Index Entries

Barak Mizrahi, Roni Lotan, Nir Kalkstein, Asaf Peretz, Galit Perez, Amir Ben-Tov, Gabriel Chodick, Sivan Gazit, and Tal Patalon
November 4, 2021
Maccabi Healthcare Services (Israel)

"Abstract: … Leveraging the centralized computerized database of Maccabi Healthcare Services (MHS), we assessed the correlation between time-from-vaccine and incidence of breakthrough infection between June 1 and July 27, the date of analysis. After controlling for potential confounders as age and comorbidities, we found a significant 1.51 fold (95% CI, 1.38–1.66) increased risk for infection for early vaccinees compared to those vaccinated later...

Results

... Individuals who were vaccinated in January 2021 had a 2.26-fold increased risk (CI 1.80-3.01) for breakthrough infection compared to individuals who were vaccinated in April 2021.

Discussion

In this cohort of MHS members, all of whom are vaccinated with the BioNTech/Pfizer mRNA BNT162b2 vaccine in a two-dose regimen, we identified a significant correlation between time-from-vaccine and afforded protection against SARS-CoV-2 infection. The risk for breakthrough infection was significantly higher for Early Vaccinees compared with those vaccinated later with an additional trend for higher risk for hospitalization among the Early Vaccinees group. Our results correspond to recent publications that demonstrate a significant decline in antibody levels and immune systems compounds over time following the second dose of vaccination."

document
breakthrough cases,clinical cases,COVID-19,vaccines