May 3, 2021

Real-World Effectiveness of Ad26.COV2.S Adenoviral Vector Vaccine for COVID-19

Category: Article Summary

Topic: Vaccines and Immunity

Keywords (Tags): vaccine

• [Pre-print, not peer-reviewed] The Johnson & Johnson/Janssen vaccine showed a real-world effectiveness of 76.7% in preventing SARS-CoV-2 infection at least two weeks after vaccination among patients in the Mayo Clinic Health system, according to an analysis comparing the infection rate among 2,195 individuals who received the vaccine to that among 21,950 unvaccinated, propensity-matched individuals between February 27th and April 14th, 2021. Of 1,779 vaccinated individuals with at least two weeks of follow-up, only 3 (0.17%) tested positive on day 15 or later after vaccination compared to 128 of 17,744 (0.72%) unvaccinated individuals, corresponding to a 4.3-fold reduction in cumulative incidence. The authors note that at the time of the study, there were not enough hospitalizations, ICU admissions, or deaths within the cohort to assess the effect of the vaccine on COVID-19 severity.

Corchado-Garcia et al. (Apr 30, 2021). Real-World Effectiveness of Ad26.COV2.S Adenoviral Vector Vaccine for COVID-19. Pre-print downloaded May 3 from https://doi.org/10.1101/2021.04.27.21256193