Sex: U
Vaccine: FLU3
Symptoms: Influenza, Influenza virus test positive, Vaccination failure
Clinical narrative: This case was reported in a literature article and described the occurrence of vaccination failure in a subject who received Flu seasonal TIV Dresden. Concurrent medical conditions included alcohol abuse. On an unknown date, less than a year after receiving Flu seasonal TIV Dresden, the subject developed vaccination failure. Serious criteria included hospitalization and GSK medically significant. Additional event(s) included influenza with serious criteria of hospitalization. The outcome of vaccination failure was unknown. The outcome(s) of the additional event(s) included influenza (unknown). The investigator considered that there was a reasonable possibility that the vaccination failure and influenza may have been caused by Flu seasonal TIV Dresden. Relevant Tests: Lab tests were performed on an unspecified date. The patient was diagnosed with laboratory-confirmed influenza. Additional information was provided. This case was reported in a literature article and described the suspected vaccination failure in a patient aged 6 months or more of unspecified gender who was vaccinated with unspecified seasonal influenza vaccine (manufacturer unknown). The patient was part of the study that examined the impact of vaccination status on outcomes among laboratory-confirmed influenza-associated hospitalizations in a particular metropolitan statistical area (MSA). Multiple seasons and all age groups eligible for vaccination were included in the analysis. The two primary outcomes of interest were severe influenza (defined as admission to the ICU or death during the hospitalization) and pneumonia. A secondary aim of this study was to assess the role of time between vaccination and hospitalisation to determine if waning immunity affected any observed secondary protective effect. In this study, each influenza season began on the 1 October and ends on the 30 April of the subsequent year. 48 were female. 73 were of a particular racial class. The patient had a current alcohol abuse. No information on patient's medical or family history or concomitant medication or concurrent condition was provided. On an unspecified date, the patient received unspecified seasonal influenza vaccine (administration site and route unspecified; dosages unknown; batch number not provided). The age of vaccination was not provided. [In this study, a patient was considered vaccinated if they received the influenza vaccine for the respective influenza season and if vaccination occurred at least 14 days before the date of hospitalisation. Patients younger than 9 years old needed to receive two doses that season or one dose in the previous season and one in the current season to be considered vaccinated]. On an unspecified date between 2012 and 2015, an unknown period after the vaccination, the patient developed the symptoms of influenza. Between 14 and 262 days after the vaccination, the patient was hospitalised. Subsequently, the patient was diagnosed with laboratory-confirmed influenza. [In this study, an influenza-associated hospitalization was defined as a person who lived within the catchment area who experienced a hospitalization with laboratory-confirmed influenza. Testing methods were chosen by the attending physician and therefore varied; testing was performed by viral culture, rapid antigen testing, or real-time reverse transcriptase-polymerase chain reaction]. The patient had not received any antiviral treatment during admission. Those who did not receive antiviral treatment were excluded from the study. The length of hospitalisation was 2-6 days. This case has been considered as suspected vaccination failure being time to onset was unknown. This case has been considered serious due to hospitalisation/suspected vaccination failure. Treatment was unknown. The outcome of the event was not reported. The authors did not comment on the event of influenza infection and unspecified seasonal influenza vaccine. The authors stated "For those who did not receive antivirals, no impact of vaccination was observed in the unadjusted or fully adjusted models for either outcome". The authors stated "this study found that influenza vaccination might provide mild protection against pneumonia for individuals who, despite receiving the influenza vaccine, experienced an influenza-associated hospitalization and were treated with antivirals. This effect was only observed in an influenza H1N1 dominant year and was potentially driven by 25-64-year-old patients. The differences in seasons may be related to vaccine matching to the predominant circulating strain, age group affected, or virus subtype. Further information from other participating sites should be analysed to elucidate the true impact of influenza vaccination on reduction of influenza-related outcomes by influenza vaccination status".