Covid-19 Vaccine Effectiveness in Healthcare Personnel in Clalit Health Services in Israel (CoVEHPI)

Study Overview
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Brief Summary
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Although clinical trials for approved COVID-19 vaccines demonstrated efficacy of the vaccine in preventing symptomatic infection, many questions about vaccine effectiveness, such as the effectiveness of COVID-19 vaccine in preventing asymptomatic infection, a surrogate for transmission, and duration of protection, can only be evaluated in real-world trials. The objective of the study is to evaluate COVID-19 vaccine effectiveness (Pfizer vaccine, and, if available, Moderna vaccine) in preventing infection in healthcare personnel in Israel. HCP who are Clalit members and working in Soroka, Beilinson, Meir, Haemek, Kaplan and Schneider hospitals, 18 years or older, and eligible to get COVID-19 vaccine according to Ministry of Health guidelines, will be recruited, regardless of their intention to get the COVID-19 vaccine. A baseline serology sample and respiratory sample will be collected. Participants will be asked to provide a respiratory sample weekly for 3 months, and then monthly for the remainder of the study. Participants will also have blood drawn at 1 month, 3 months, 6 months, 9 months and 12 months. Respiratory samples will be tested for SARS-CoV-2 by RT-PCR; serology will be tested for SARS-CoV-2 antibodies. The study will last for 12 months. For each participant, data will be extracted from the Electronic Medical Record for the period of the study and retrospectively from 2010.

Official Title
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Covid-19 Vaccine Effectiveness in Healthcare Personnel in Clalit Health Services in Israel (CoVEHPI): A Prospective Cohort Study

Conditions
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Covid19, Corona Virus Infection, Vaccine Effectiveness

Intervention / Treatment
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* Diagnostic Test: Serologic test
* Diagnostic Test: Respiratory swabs


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - Any HCP at any of the participating hospitals who is a member of Clalit Health Services is eligible to get the Covid-19 vaccine did not receive the first dose of COVID-19 vaccine more than 21 days prior to the enrollment date Exclusion Criteria: - Employees at any of the participating hospitals will be excluded if they are: not a member of Clalit Health Services; or not eligible to get the Covid-19 vaccine according to the Ministry of Health guidelines; or Less than 18 years of age Received first dose of COVID-19 vaccine more than 21 days prior to date of enrollment

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 120 Years

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<br>participants who received the Covid-19 vaccine | Diagnostic Test: Serologic test<br>* A blood test to check antibodies type and amount<br>Diagnostic Test: Respiratory swabs<br>* PCR test to Covid-19<br>|
| unvaccinated<br>participants who didn't received the Covid-19 vaccine | Diagnostic Test: Serologic test<br>* A blood test to check antibodies type and amount<br>Diagnostic Test: Respiratory swabs<br>* PCR test to Covid-19<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| COVID-19 vaccine effectiveness (VE) | Incidence of SARS-CoV-2 infections in healthcare workers vaccinated with COVID-19 vaccine compared to unvaccinated healthcare workers | 18 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Symptomatic SARS-CoV-2 infection in vaccinated vs. unvaccinated healthcare workers | Incidence of symptomatic SARS-CoV-2 infections in healthcare workers vaccinated with COVID-19 vaccine compared to unvaccinated healthcare workers | 18 months | 
| asymptomatic SARS-CoV-2 infection in vaccinated vs. unvaccinated healthcare workers | Incidence of symptomatic SARS-CoV-2 infections in healthcare workers vaccinated with COVID-19 vaccine compared to unvaccinated healthcare workers | 18 months | 
| Duration of effectiveness of the vaccine | Incidence of SARS-CoV-2 infections in healthcare workers vaccinated with COVID-19 vaccine compared to unvaccinated healthcare workers over different periods of time | 18 months | 
| Vaccine Effectiveness by age | Incidence of SARS-CoV-2 infections in healthcare workers vaccinated with COVID-19 vaccine compared to unvaccinated healthcare workers of different age groups | 18 months | 
| Vaccine Effectiveness by comorbidity | Incidence of SARS-CoV-2 infections in healthcare workers vaccinated with COVID-19 vaccine compared to unvaccinated healthcare workers by various underly medical conditions | 18 months | 
| Vaccine effectiveness in persons previously infected with SARS-CoV-2 virus | Incidence of SARS-CoV-2 infections in previously infection healthcare workers vaccinated with COVID-19 vaccine compared to previously infection unvaccinated healthcare workers | 18 months | 
| VE by degree of exposure to COVID-19 patients | Incidence of SARS-CoV-2 infections in healthcare workers vaccinated with COVID-19 vaccine compared to unvaccinated healthcare workers by degree of occupational exposure to COVID-019 patients | 18 months | 
| VE by different SARS-CoV-2 variants | Incidence of SARS-CoV-2 infections in healthcare workers vaccinated with COVID-19 vaccine compared to unvaccinated healthcare workers for different variant strains of SARS-CoV-2 | 18 months | 
| Vaccine effectiveness of one dose compared to two doses | Incidence of SARS-CoV-2 infections in healthcare workers vaccinated with two doses of COVID-19 vaccine compared to healthcare workers vaccinated with two doses of COVID-19 vaccine | 18 months | 
| Compartive vaccine Effectiveness of different vaccine brands | Incidence of SARS-CoV-2 infections in healthcare workers vaccinated with different brands of COVID-19 vaccine | 18 months |