Evidence for increased breakthrough rates of SARS-CoV-2 variants of concern in BNT162b2-mRNA-vaccinated individuals

Abstract

The BNT162b2 mRNA vaccine is highly effective against SARS-CoV-2. However, apprehension exists that variants of concern (VOCs) may evade vaccine protection, due to evidence of reduced neutralization of the VOCs B.1.1.7 and B.1.351 by vaccine sera in laboratory assays. We performed a matched cohort study to examine the distribution of VOCs in infections of BNT162b2 mRNA vaccinees from Clalit Health Services (Israel) using viral genomic sequencing, and hypothesized that if vaccine effectiveness against a VOC is reduced, its proportion among breakthrough cases would be higher than in unvaccinated controls. Analyzing 813 viral genome sequences from nasopharyngeal swabs, we showed that vaccinees who tested positive at least 7 days after the second dose were disproportionally infected with B.1.351, compared with controls. Those who tested positive between 2 weeks after the first dose and 6 days after the second dose were disproportionally infected by B.1.1.7. These findings suggest reduced vaccine effectiveness against both VOCs within particular time windows. Our results emphasize the importance of rigorously tracking viral variants, and of increasing vaccination to prevent the spread of VOCs.

Dominance of Alpha and Iota variants in SARS-CoV-2 vaccine breakthrough infections in New York City

“…Our finding that B.1.1.7 and B.1.526 are not preferentially represented in the vaccine breakthrough group but distributed at similar proportions as other variants in case and control groups suggests that the studied mRNA vaccines are comparably effective against these predominant variants in the NYC area. This is in agreement with recent data from Israel evaluating B.1.1.7 in this context 17 . A sieve effect of the B.1.526 variant has not been studied in this detail, except for two studies with small sample sizes of n=2 and n=11 that did not allow strong conclusions 14,19 .…”

Clinical characterization and Genomic analysis of COVID-19 breakthrough infections during second wave in different states of India

“…The copyright holder for this preprint this version posted July 15, 2021. ; https://doi.org/10.1101/2021.07. 13.21260273 doi: medRxiv preprint NOTE: This preprint reports new research that has not been certified by peer review and should not be used to guide clinical practice.…”

Viral and Immunological Characteristics of COVID-19 Vaccine Breakthrough Infections

“…We next found that the virus detected among breakthrough cases matched the viruses circulating both temporally and spatially. Several reports have suggested increased breakthrough rates of SARS-CoV-2 variants of concern and variants with mutations known to escape antibodies in vitro [9][10] . In our investigation, when there was major transmission of the R.1 lineage, which contains the E484K mutation (known to escape antibodies in vitro 11 ), we saw several breakthrough cases with this lineage.…”