Sumary of Increased risk of breakthrough SARS-CoV-2 infection with ChAdOx1 compared to BNT162b2 vaccine:
- Study: Waning of SARS-CoV-2 antibodies targeting the Spike protein in individuals post second dose of ChAdOx1 and BNT162b2 COVID-19 vaccines and risk of breakthrough infections: analysis of the Virus Watch community cohort.
- however, 79% of recent coronavirus disease 2019 (COVID-19) deaths in the U.K. have occurred as a result of breakthrough infections in double vaccinated individuals at least 14 days prior to the positive SARS-CoV-2 test.
- Given the high levels of breakthrough infections and subsequent deaths occurring in double vaccinated individuals, it is important to understand trajectories of anti-S waning in individuals after they have received their second dose of the COVID- 19 vaccine.
- Furthermore, it is important to determine whether the timing of their second dose can be used as a correlate of protection for SARS-CoV-2 infection in an effort to inform vaccine policies around the world.
- A total of 24,049 samples from 8,858 individuals, 5,549 of whom received a second dose of ChAdOx1 and 3,205 received BNT162b2 vaccines, who remained anti-nucleocapsid (anti-N) antibody negative, were included in the analysis of anti-S waning over time.
- Anti-S level, a meaningful correlate of protection against SARS-Cov-2 infection Related StoriesIn total, data from 8,275 individuals were analyzed for anti-S levels prior to breakthrough infection to examine anti-S as a correlate of protection against SARS-Cov-2 infection.
- During the timeline for this particular study, the team observed 197 breakthrough infection cases.
- Further, they found that individuals with anti-S levels less than 500 U/ml following the second dose were nearly twice as likely to experience a breakthrough infection compared to those with higher levels.