Association of receiving a fourth dose of the BNT162b vaccine with SARS-CoV-2 infection among healthcare workers in Israel

Aug. 4, 2022
Was there a benefit of vaccinating healthcare workers with a fourth dose of BNT162b2 vaccine during the Omicron variant outbreak of the COVID-19 pandemic?

In this multicenter cohort study of 29 611 healthcare workers in Israel, the breakthrough infection rate among those who received 4 doses was 6.9% compared with 19.8% in those who received 3 doses. The study was published in JAMA Network Open.

These findings suggest that a fourth vaccine dose was effective in preventing breakthrough COVID-19 infections in healthcare workers, helping to maintain the function of the healthcare system during the pandemic.

In this multicenter cohort study of HCWs in 11 general hospitals in Israel, researchers found that 4-dose vaccine recipients had a lower risk of acquiring COVID-19 than 3-dose recipients during the peak Omicron variant wave. The benefit of the fourth vaccine was significant in subgroup analyses (sex, age group, and profession) and in most participating hospitals. These results were consistent and significant in the matched analysis and the Cox proportional hazards regression model as well, albeit less prominent.

Read the full study here