Post-authorisation Passive Enhanced Safety Surveillance of Seasonal Influenza Vaccines: Pilot Study in England

Study Overview
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Brief Summary
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This pilot study, to be conducted in the 2017/2018 influenza season, is a safety surveillance study using passive surveillance enhanced with a reporting card system to report adverse events of interest (AEIs) after Flu vaccination.

Detailed Description
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This is the third pilot study following, EPI-FLU-045 VS UK [NCT02567721] and EPI-FLU-046 VS UK [NCT02893878] studies, carried out in the 2 previous influenza seasons (2015/2016 and 2016/2017). This study will collect data about vaccination status and adverse events following influenza immunisation (AEFI) on a weekly basis, from 01 September 2017 onwards, using a customized Adverse Drug Reaction (ADR) Cards and data from Electronic Health Records system for a period of approximately 13 weeks.

Official Title
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Post-authorisation Passive Enhanced Safety Surveillance of Seasonal Influenza Vaccines: Pilot Study in England 2017/18

Conditions
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Influenza, Human

Intervention / Treatment
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* Other: Enhanced vaccine safety surveillance


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All individuals who receive influenza vaccination among the 10 participating GP practices between 1 September and 30 November 2017 are eligible for inclusion in the analysis. Exclusion Criteria: Registered patients who have explicitly opted out of data sharing will be excluded from the analysis.

Ages Eligible for Study
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Minimum Age: 6 Months

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Vaccinated_Fluarix Tetra Group<br>Volunteered subjects who received GlaxoSmithKline's (GSK's) influenza vaccination (Fluarix Tetra) in 10 volunteer GP practices between 01 September and 30 November 2017. | Other: Enhanced vaccine safety surveillance<br>* Routinely collected primary care data from up to ten general practices to support passive surveillance. Additionally, this passive surveillance will be enhanced by the use of a customized card-based ADR reporting system.<br>* Other names: Data collection;|
| Vaccinated_Non GSK Group<br>Volunteered subjects who received non-GSK influenza vaccination in 10 volunteer GP practices between 01 September and 30 November 2017. | Other: Enhanced vaccine safety surveillance<br>* Routinely collected primary care data from up to ten general practices to support passive surveillance. Additionally, this passive surveillance will be enhanced by the use of a customized card-based ADR reporting system.<br>* Other names: Data collection;|
| Vaccinated_Unknown Group<br>Volunteered subjects who received influenza vaccination (GSK or non-GSK not known) in 10 volunteer GP practices between 01 September and 30 November 2017. | Other: Enhanced vaccine safety surveillance<br>* Routinely collected primary care data from up to ten general practices to support passive surveillance. Additionally, this passive surveillance will be enhanced by the use of a customized card-based ADR reporting system.<br>* Other names: Data collection;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Weekly Incidence Rates of Any Adverse Events of Interest (AEIs) Reported Via Adverse Drug Reaction (ADR) Card, by Vaccine Group | The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Any AEIs Reported Via ADR Card, by Vaccine Group | The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Fever/Pyrexia Adverse Events Reported Via ADR Card, by Vaccine Group | Fever/pyrexia = all subjects with a fever/pyrexia read code recorded were considered as having fever/pyrexia, regardless of what temperature had been recorded. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Fever/Pyrexia Adverse Events Reported Via ADR Card, by Vaccine Group | Fever/pyrexia = all subjects with a fever/pyrexia read code recorded were considered as having fever/pyrexia, regardless of what temperature had been recorded. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Local Symptoms Reported Via ADR Card, by Vaccine Group | Local symptoms include local erythema. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Local Symptoms Reported Via ADR Card, by Vaccine Group | Local symptoms include local erythema. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of General Non-specific Symptoms Reported Via ADR Card, by Vaccine Group | General non-specific symptoms include any general non-specific symptoms, drowsiness, fatigue, headache, irritability, and malaise. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of General Non-specific Symptoms Reported Via ADR Card, by Vaccine Group | General non-specific symptoms include any general non-specific symptoms, drowsiness, fatigue, headache, irritability, and malaise. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Respiratory/Miscellaneous Adverse Events Reported Via ADR Card, by Vaccine Group | Respiratory/miscellaneous adverse events include any respiratory/miscellaneous adverse events, conjunctivitis, coryza, cough, epistaxis, hoarseness, nasal congestion, oropharyngeal pain, rhinorrhoea and wheezing. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Respiratory/Miscellaneous Adverse Events Reported Via ADR Card, by Vaccine Group | Respiratory/miscellaneous adverse events include any respiratory/miscellaneous adverse events, conjunctivitis, coryza, cough, epistaxis, hoarseness, nasal congestion, oropharyngeal pain, rhinorrhoea and wheezing. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Gastrointestinal Adverse Events Reported Via ADR Card, by Vaccine Group | Gastrointestinal adverse events include any gastrointestinal adverse events, decreased appetite, diarrhea, nausea, and vomiting. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Gastrointestinal Adverse Events Reported Via ADR Card, by Vaccine Group | Gastrointestinal adverse events include any gastrointestinal adverse events, decreased appetite, diarrhea, nausea and, vomiting. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Sensitivity/Anaphylaxis Adverse Events Reported Via ADR Card, by Vaccine Group | Sensitivity/anaphylaxis adverse events include any sensitivity/anaphylaxis adverse events, anaphylactic reactions, facial edema, and hypersensitivity reactions. The weekly incidence rates expressed as the percentage of subjects, of AEIs were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Sensitivity/Anaphylaxis Adverse Events Reported Via ADR Card, by Vaccine Group | Sensitivity/anaphylaxis adverse events include any sensitivity/anaphylaxis adverse events, anaphylactic reactions, facial edema, and hypersensitivity reactions. The cumulative incidence rates expressed as the percentage of subjects, of AEIs were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Rash Adverse Events Reported Via ADR Card, by Vaccine Group | The weekly incidence rates expressed as the percentage of subjects, of AEIs were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Rash Adverse Events Reported Via ADR Card, by Vaccine Group | The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Musculoskeletal Adverse Events Reported Via ADR Card, by Vaccine Group | Musculoskeletal adverse events include any musculoskeletal adverse events, arthropathy, and muscle aches/myalgia. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Musculoskeletal Adverse Events Reported Via ADR Card, by Vaccine Group | Musculoskeletal adverse events include any musculoskeletal adverse events, arthropathy, and muscle aches/myalgia. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Neurological Adverse Events Reported Via ADR Card, by Vaccine Group | Neurological adverse events include any neurological adverse events, Bell's palsy, Guillain-Barre Syndrome, peripheral tremor and seizure/febrile convulsions. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Neurological Adverse Events Reported Via ADR Card, by Vaccine Group | Neurological adverse events include any neurological adverse events, Bell's palsy, Guillain-Barre Syndrome, peripheral tremor and seizure/febrile convulsions. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of SAEs Reported Via ADR Card by Vaccine Group | The weekly incidence rates of SAEs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card; The numerator was the number of subjects from the denominator who reported any SAEs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine. Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of SAEs Reported Via ADR Card by Vaccine Group | The cumulative incidence rates of SAEs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card; The numerator was the number of subjects from the denominator who reported any SAEs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine. Vaccination of the subjects happened between week 35 and week 48 of the year 2017. | Within 7 days post vaccination | 
| Weekly Incidence Rates of Any AEIs Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Any AEIs Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Fever/Pyrexia Adverse Events Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Fever/pyrexia = all subjects with a fever/pyrexia read code recorded were considered as having fever/pyrexia, regardless of what temperature had been recorded. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Fever/Pyrexia Adverse Events Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Fever/pyrexia = all subjects with a fever/pyrexia read code recorded were considered as having fever/pyrexia, regardless of what temperature had been recorded. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Local Symptoms Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Local symptoms include local erythema. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Local Symptoms Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Local symptoms include local erythema. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of General Non-specific Symptoms Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. General non-specific symptoms include any general non-specific symptoms, drowsiness, fatigue, headache, irritability, and malaise. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of General Non-specific Symptoms Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. General non-specific symptoms include any general non-specific symptoms, drowsiness, fatigue, headache, irritability, and malaise. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Respiratory/Miscellaneous Adverse Events Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Respiratory/miscellaneous adverse events include any respiratory/miscellaneous adverse events, conjunctivitis, coryza, cough, epistaxis, hoarseness, nasal congestion, oropharyngeal pain, rhinorrhoea and wheezing. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Respiratory/Miscellaneous Adverse Events Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Respiratory/miscellaneous adverse events include any respiratory/miscellaneous adverse events, conjunctivitis, coryza, cough, epistaxis, hoarseness, nasal congestion, oropharyngeal pain, rhinorrhoea and wheezing. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Gastrointestinal Adverse Events Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Gastrointestinal adverse events include any gastrointestinal adverse events, decreased appetite, diarrhoea, nausea and vomiting. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Gastrointestinal Adverse Events Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Gastrointestinal adverse events include any gastrointestinal adverse events, decreased appetite, diarrhea, nausea, and vomiting. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Sensitivity/Anaphylaxis Adverse Events Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Sensitivity/anaphylaxis adverse events include any sensitivity/anaphylaxis adverse events, anaphylactic reactions, facial oedema and hypersensitivity reactions. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Sensitivity/Anaphylaxis Adverse Events Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Sensitivity/anaphylaxis adverse events include any sensitivity/anaphylaxis adverse events, anaphylactic reactions, facial edema, and hypersensitivity reactions. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Rash Adverse Events Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Rash Adverse Events Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Musculoskeletal Adverse Events Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Musculoskeletal adverse events include any musculoskeletal adverse events, arthropathy, and muscle aches/myalgia. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Musculoskeletal Adverse Events Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Musculoskeletal adverse events include any musculoskeletal adverse events, arthropathy, and muscle aches/myalgia. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Neurological Adverse Events Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Neurological adverse events include any neurological adverse events, Bell's palsy, Guillain-Barre Syndrome, peripheral tremor and seizure/febrile convulsions. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Neurological Adverse Events Reported Via ADR Card, by Vaccine and Age Group | AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Neurological adverse events include any neurological adverse events, Bell's palsy, Guillain-Barre Syndrome, peripheral tremor and seizure/febrile convulsions. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Serious Adverse Events (SAEs) Reported Via ADR Card, by Vaccine and Age Group | SAE data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. The weekly incidence rates of SAEs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any SAEs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of SAEs Reported Via ADR Card, by Vaccine and Age Group | SAE data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. The cumulative incidence rates of SAEs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any SAEs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Any AEIs Reported Via ADR Card, by Vaccine Group and United Kingdom Chief Medical Officer (UK CMO)-Specified Risk Status | The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Any AEIs Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Fever/Pyrexia Adverse Events Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | Fever/pyrexia = all subjects with a fever/pyrexia read code recorded were considered as having fever/pyrexia, regardless of what temperature had been recorded. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Fever/Pyrexia Adverse Events Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | Fever/pyrexia = all subjects with a fever/pyrexia read code recorded were considered as having fever/pyrexia, regardless of what temperature had been recorded. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Local Symptoms Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | Local symptoms include local erythema. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Local Symptoms Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | Local symptoms include local erythema. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of General Non-specific Symptoms Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | General non-specific symptoms include any general non-specific symptoms, drowsiness, fatigue, headache, irritability and malaise. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of General Non-specific Symptoms Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | General non-specific symptoms include any general non-specific symptoms, drowsiness, fatigue, headache, irritability, and malaise. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Respiratory/Miscellaneous Adverse Events Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | Respiratory/miscellaneous adverse events include any respiratory/miscellaneous adverse events, conjunctivitis, coryza, cough, epistaxis, hoarseness, nasal congestion, oropharyngeal pain, rhinorrhoea and wheezing. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Respiratory/Miscellaneous Adverse Events Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | Respiratory/miscellaneous adverse events include any respiratory/miscellaneous adverse events, conjunctivitis, coryza, cough, epistaxis, hoarseness, nasal congestion, oropharyngeal pain, rhinorrhoea and wheezing. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Gastrointestinal Adverse Events Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | Gastrointestinal adverse events include any gastrointestinal adverse events, decreased appetite, diarrhea, nausea, and vomiting. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Gastrointestinal Adverse Events Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | Gastrointestinal adverse events include any gastrointestinal adverse events, decreased appetite, diarrhea, nausea, and vomiting. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Sensitivity/Anaphylaxis Adverse Events Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | Sensitivity/anaphylaxis adverse events include any sensitivity/anaphylaxis adverse events, anaphylactic reactions, facial edema, and hypersensitivity reactions. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Sensitivity/Anaphylaxis Adverse Events Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | Sensitivity/anaphylaxis adverse events include any sensitivity/anaphylaxis adverse events, anaphylactic reactions, facial edema, and hypersensitivity reactions. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Rash Adverse Events Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Rash Adverse Events Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Musculoskeletal Adverse Events Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | Musculoskeletal adverse events include any musculoskeletal adverse events, arthropathy, and muscle aches/myalgia. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Musculoskeletal Adverse Events Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | Musculoskeletal adverse events include any musculoskeletal adverse events, arthropathy, and muscle aches/myalgia. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Neurological Adverse Events Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | Neurological adverse events include any neurological adverse events, Bell's palsy, Guillain-Barre Syndrome, peripheral tremor and seizure/febrile convulsions. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Neurological Adverse Events Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | Neurological adverse events include any neurological adverse events, Bell's palsy, Guillain-Barre Syndrome, peripheral tremor and seizure/febrile convulsions. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of SAEs Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | The weekly incidence rates of SAEs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any SAEs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of SAEs Reported Via ADR Card, by Vaccine Group and UK CMO-specified Risk Status | The cumulative incidence rates of SAEs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any SAEs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Weekly Incidence Rates of Any AEIs Recorded in Electronic Health Record (EHR), by Vaccine Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from General Practitioners (GPs). The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Fever/Pyrexia Adverse Events Recorded in EHR, by Vaccine Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Fever/pyrexia = all subjects with a fever/pyrexia read code recorded were considered as having fever/pyrexia, regardless of what temperature had been recorded. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Local Symptoms Recorded in EHR, by Vaccine Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Local symptoms include local erythema. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of General Non-specific Symptoms Recorded in EHR, by Vaccine Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. General non-specific symptoms include any general non-specific symptoms, drowsiness, fatigue, headache, irritability, and malaise. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Respiratory/Miscellaneous Adverse Events Recorded in EHR, by Vaccine Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Respiratory/miscellaneous adverse events include any respiratory/miscellaneous adverse events, conjunctivitis, coryza, cough, epistaxis, hoarseness, nasal congestion, oropharyngeal pain, rhinorrhoea and wheezing. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Gastrointestinal Adverse Events Recorded in EHR, by Vaccine Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Gastrointestinal adverse events include any gastrointestinal adverse events, decreased appetite, diarrhoea, nausea, and vomiting. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Sensitivity/Anaphylaxis Adverse Events Recorded in EHR, by Vaccine Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Sensitivity/anaphylaxis adverse events include any sensitivity/anaphylaxis adverse events, anaphylactic reactions, facial edema, and hypersensitivity reactions. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Rash Adverse Events Recorded in EHR, by Vaccine Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Musculoskeletal Adverse Events Recorded in EHR, by Vaccine Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Musculoskeletal adverse events include any musculoskeletal adverse events, arthropathy, and muscle aches/myalgia. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Neurological Adverse Events Recorded in EHR, by Vaccine Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Neurological adverse events include any neurological adverse events, Bell's palsy, Guillain-Barre Syndrome, peripheral tremor and seizure/febrile convulsions. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of SAEs Recorded in EHR, by Vaccine Group | SAEs reported here are derived from 2 sources of data - ADR cards and SAE routinely collected from GPs. The weekly incidence rates of SAEs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any SAEs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Any AEIs Recorded in EHR, by Vaccine Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Fever/Pyrexia Adverse Events Recorded in EHR, by Vaccine Group | subjects with a fever/pyrexia read code recorded were considered as having fever/pyrexia, regardless of what temperature had been recorded. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Local Symptoms Recorded in EHR, by Vaccine Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Local symptoms include local erythema. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of General Non-specific Symptoms Recorded in EHR, by Vaccine Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. General non-specific symptoms include any general non-specific symptoms, drowsiness, fatigue, headache, irritability, and malaise. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Respiratory/Miscellaneous Adverse Events Recorded in EHR, by Vaccine Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Respiratory/miscellaneous adverse events include any respiratory/miscellaneous adverse events, conjunctivitis, coryza, cough, epistaxis, hoarseness, nasal congestion, oropharyngeal pain, rhinorrhoea and wheezing. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Gastrointestinal Adverse Events Recorded in EHR, by Vaccine Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Gastrointestinal adverse events include any gastrointestinal adverse events, decreased appetite, diarrhoea, nausea, and vomiting. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who received the ADR card The numerator was the number of subjects from the denominator who reported any AEIs on the ADR card within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Sensitivity/Anaphylaxis Adverse Events Recorded in EHR, by Vaccine Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Sensitivity/anaphylaxis adverse events include any sensitivity/anaphylaxis adverse events, anaphylactic reactions, facial edema, and hypersensitivity reactions. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Rash Adverse Events Recorded in EHR, by Vaccine Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. The cumulative incidence rates AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Musculoskeletal Adverse Events Recorded in EHR, by Vaccine Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Musculoskeletal adverse events include any musculoskeletal adverse events, arthropathy and muscle aches/myalgia. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Neurological Adverse Events Recorded in EHR, by Vaccine Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Neurological adverse events include any neurological adverse events, Bell's palsy, Guillain-Barre Syndrome, peripheral tremor and seizure/febrile convulsions. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of SAEs Recorded in EHR, by Vaccine Group | SAEs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. The cumulative incidence rates of SAEs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Any AEIs Recorded in EHR, by Vaccine and Age Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Any AEIs Recorded in EHR, by Vaccine and Age Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Fever/Pyrexia Adverse Events Recorded in EHR, by Vaccine and Age Group | AEIs reported here are derived from 2 data sources - ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years, and >65 years. Fever/pyrexia = all subjects with a fever/pyrexia read code recorded were considered as having fever/pyrexia, regardless of what temperature had been recorded. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with seasonal influenza vaccine Vaccination of subjects happened between weeks 35 and 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Fever/Pyrexia Adverse Events Recorded in EHR, by Vaccine and Age Group | AEIs reported here are derived from 2 data sources - ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12, 13 to 17, 18 to 65, and >65 years. Fever/pyrexia = all subjects with a fever/pyrexia read code recorded were considered as having fever/pyrexia, regardless of what temperature had been recorded. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between weeks 35 and 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Local Symptoms Recorded in EHR, by Vaccine and Age Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Local symptoms include local erythema. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Local Symptoms Recorded in EHR, by Vaccine and Age Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Local symptoms include local erythema. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of General Non-specific Symptoms Recorded in EHR, by Vaccine and Age Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. General non-specific symptoms include any general non-specific symptoms, drowsiness, fatigue, headache, irritability, and malaise. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of General Non-specific Symptoms Recorded in EHR, by Vaccine and Age Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. General non-specific symptoms include any general non-specific symptoms, drowsiness, fatigue, headache, irritability, and malaise. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Respiratory/Miscellaneous Adverse Events Recorded in EHR, by Vaccine and Age Group | AEIs reported are derived from 2 data sources: ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12, 13 to 17, 18 to 65, and >65 years. Respiratory/miscellaneous adverse events include any respiratory/miscellaneous adverse events, conjunctivitis, coryza, cough, epistaxis, hoarseness, nasal congestion, oropharyngeal pain, rhinorrhea, and wheezing. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator = the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator = the number of subjects from the denominator who reported any AEIs in EHR (routine data collection + card-based ADR reporting system) within 7 days following vaccination with seasonal influenza vaccine Vaccination happened between weeks 35 and 48, of 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Respiratory/Miscellaneous Adverse Events Recorded in EHR, by Vaccine and Age Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12, 13 to 17, 18 to 65, and >65 years. Respiratory/miscellaneous adverse events include any respiratory/miscellaneous adverse events, conjunctivitis, coryza, cough, epistaxis, hoarseness, nasal congestion, oropharyngeal pain, rhinorrhea, and wheezing. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (routine data collection + ADR) within 7 days following vaccination with seasonal influenza vaccine Vaccination of the subjects happened between weeks 35 and 48, 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Gastrointestinal Adverse Events Recorded in EHR, by Vaccine and Age Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Gastrointestinal adverse events include any gastrointestinal adverse events, decreased appetite, diarrhea, nausea, and vomiting. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Gastrointestinal Adverse Events Recorded in EHR, by Vaccine and Age Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Gastrointestinal adverse events include any gastrointestinal adverse events, decreased appetite, diarrhoea, nausea and vomiting. The cumulative incidence rates of AEIs expressed as a cumulative percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system); The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine. Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Sensitivity/Anaphylaxis Adverse Events Recorded in EHR, by Vaccine and Age Group | AEIs reported here are derived from 2 data sources: ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Sensitivity/anaphylaxis adverse events include any sensitivity/anaphylaxis adverse events, anaphylactic reactions, facial edema, and hypersensitivity reactions. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between weeks 35 and 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Sensitivity/Anaphylaxis Adverse Events Recorded in EHR, by Vaccine and Age Group | AEIs reported here are derived from 2 data sources: ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Sensitivity/anaphylaxis adverse events include any sensitivity/anaphylaxis adverse events, anaphylactic reactions, facial edema, and hypersensitivity reactions. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between weeks 35 and 48 of 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Rash Adverse Events Recorded in EHR, by Vaccine and Age Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Rash Adverse Events Recorded in EHR, by Vaccine and Age Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Musculoskeletal Adverse Events Recorded in EHR, by Vaccine and Age Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Musculoskeletal adverse events include any musculoskeletal adverse events, arthropathy, and muscle aches/myalgia. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Musculoskeletal Adverse Events Recorded in EHR, by Vaccine and Age Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Musculoskeletal adverse events include any musculoskeletal adverse events, arthropathy and muscle aches/myalgia. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Neurological Adverse Events Recorded in EHR, by Vaccine and Age Group | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Neurological adverse events include any neurological adverse events, Bell's palsy, Guillain-Barre Syndrome, peripheral tremor and seizure/febrile convulsions. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between weeks 35 and 48 of 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Neurological Adverse Events Recorded in EHR, by Vaccine and Age Group | AEIs reported here are derived from 2 data sources: ADR cards and AEI routinely collected from GPs. AEI data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. Neurological adverse events include any neurological adverse events, Bell's palsy, Guillain-Barre Syndrome, peripheral tremor and seizure/febrile convulsions. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between weeks 35 and 48 of 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of SAEs Recorded in EHR, by Vaccine and Age Group | SAEs reported here are derived from 2 sources of data - ADR cards and SAEs routinely collected from GPs. SAE data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. The weekly incidence rates of SAEs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of SAEs Recorded in EHR, by Vaccine and Age Group | SAEs reported here are derived from 2 sources of data - ADR cards and SAEs routinely collected from GPs. SAE data was presented by age strata: 6 months to 5 years, 6 to 12 years, 13 to 17 years, 18 to 65 years and >65 years. The cumulative incidence rates of SAEs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Any AEIs Recorded in EHR, by Vaccine Group and United Kingdom Chief Medical Officer (UK CMO)-Specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Any AEIs Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Fever/Pyrexia Adverse Events Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Fever/pyrexia = all subjects with a fever/pyrexia read code recorded were considered as having fever/pyrexia, regardless of what temperature had been recorded. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Fever/Pyrexia Adverse Events Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Fever/pyrexia = all subjects with a fever/pyrexia read code recorded were considered as having fever/pyrexia, regardless of what temperature had been recorded. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Local Symptoms Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Local symptoms include local erythema. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Local Symptoms Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Local symptoms include local erythema. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of General Non-specific Symptoms Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. General non-specific symptoms include any general non-specific symptoms, drowsiness, fatigue, headache, irritability, and malaise. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of General Non-specific Symptoms Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. General non-specific symptoms include any general non-specific symptoms, drowsiness, fatigue, headache, irritability, and malaise. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Respiratory/Miscellaneous Adverse Events Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Respiratory/miscellaneous adverse events include any respiratory/miscellaneous adverse events, conjunctivitis, coryza, cough, epistaxis, hoarseness, nasal congestion, oropharyngeal pain, rhinorrhoea and wheezing. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Respiratory/Miscellaneous Adverse Events Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Respiratory/miscellaneous adverse events include any respiratory/miscellaneous adverse events, conjunctivitis, coryza, cough, epistaxis, hoarseness, nasal congestion, oropharyngeal pain, rhinorrhoea and wheezing. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Gastrointestinal Adverse Events Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Gastrointestinal adverse events include any gastrointestinal adverse events, decreased appetite, diarrhea, nausea, and vomiting. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Gastrointestinal Adverse Events Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Gastrointestinal adverse events include any gastrointestinal adverse events, decreased appetite, diarrhea, nausea, and vomiting. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Sensitivity/Anaphylaxis Adverse Events Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Sensitivity/anaphylaxis adverse events include any sensitivity/anaphylaxis adverse events, anaphylactic reactions, facial edema, and hypersensitivity reactions. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Sensitivity/Anaphylaxis Adverse Events Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Sensitivity/anaphylaxis adverse events include any sensitivity/anaphylaxis adverse events, anaphylactic reactions, facial edema, and hypersensitivity reactions. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Rash Adverse Events Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Rash Adverse Events Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Musculoskeletal Adverse Events Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Musculoskeletal adverse events include any musculoskeletal adverse events, arthropathy, and muscle aches/myalgia. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Musculoskeletal Adverse Events Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Musculoskeletal adverse events include any musculoskeletal adverse events, arthropathy, and muscle aches/myalgia. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of Neurological Adverse Events Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Neurological adverse events include any neurological adverse events, Bell's palsy, Guillain-Barre Syndrome, peripheral tremor and seizure/febrile convulsions. The weekly incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of Neurological Adverse Events Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | AEIs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. Neurological adverse events include any neurological adverse events, Bell's palsy, Guillain-Barre Syndrome, peripheral tremor and seizure/febrile convulsions. The cumulative incidence rates of AEIs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any AEIs in EHR (combining routine data collection and card-based ADR reporting system) within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Weekly Incidence Rates of SAEs Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | SAEs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. The weekly incidence rates of SAEs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Weekly vaccinated cohort for the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any SAEs in EHR (combining routine data collection and card-based ADR reporting system)within 7 days following vaccination with the seasonal influenza vaccine Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 
| Cumulative Incidence Rates of SAEs Recorded in EHR, by Vaccine Group and UK CMO-specified Risk Status | SAEs reported here are derived from 2 sources of data - ADR cards and AEI routinely collected from GPs. The cumulative incidence rates of SAEs expressed as the percentage of subjects, were estimated as follows: The denominator was the number of subjects in the Cumulative vaccinated cohort up to the week of interest who were registered in EHR (combining routine data collection and card-based ADR reporting system) The numerator was the number of subjects from the denominator who reported any SAEs in EHR (combining routine data collection and card-based ADR reporting system) Vaccination of the subjects happened between week 35 and week 48 of the year 2017 | Within 7 days post vaccination | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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England, Adverse Event of Interest, Seasonal influenza vaccines, Pilot study, Prospective passive enhanced safety surveillance