Effectiveness of COVID-19 vaccines against the B.1.617.2 variant

Abstract

Background: The B.1.617.2 COVID-19 variant has contributed to the surge in cases in India and has now been detected across the globe, including a notable increase in cases in the UK. We estimate the effectiveness of the BNT162b2 and ChAdOx1 COVID-19 vaccines against this variant. Methods: A test negative case control design was used to estimate the effectiveness of vaccination against symptomatic disease with both variants over the period that B.1.617.2 began circulating with cases identified based on sequencing and S-gene target status. Data on all symptomatic sequenced cases of COVID-19 in England was used to estimate the proportion of cases with B.1.617.2 compared to the predominant strain (B.1.1.7) by vaccination status. Results: Effectiveness was notably lower after 1 dose of vaccine with B.1.617.2 cases 33.5% (95%CI: 20.6 to 44.3) compared to B.1.1.7 cases 51.1% (95%CI: 47.3 to 54.7) with similar results for both vaccines. With BNT162b2 2 dose effectiveness reduced from 93.4% (95%CI: 90.4 to 95.5) with B.1.1.7 to 87.9% (95%CI: 78.2 to 93.2) with B.1.617.2. With ChAdOx1 2 dose effectiveness reduced from 66.1% (95% CI: 54.0 to 75.0) with B.1.1.7 to 59.8% (95%CI: 28.9 to 77.3) with B.1.617.2. Sequenced cases detected after 1 or 2 doses of vaccination had a higher odds of infection with B.1.617.2 compared to unvaccinated cases (OR 1.40; 95%CI: 1.13-1.75). Conclusions: After 2 doses of either vaccine there were only modest differences in vaccine effectiveness with the B.1.617.2 variant. Absolute differences in vaccine effectiveness were more marked with dose 1. This would support maximising vaccine uptake with two doses among vulnerable groups.

COVID-19: Unmasking Emerging SARS-CoV-2 Variants, Vaccines and Therapeutic Strategies

“…(2.7-3.8-fold) [191,192] Vaccine efficacy slightly lower or unchanged, largely preserved neutralizing titers 1. BNT162b2: 89.5-93.4% [200,217] 2. NVX-CoV2373: 86% [222].…”

“…2. Partially evaded neutralization by the antibodies induced through natural infection [214,217] 1. BNT162b2 vaccine: 90% [217].…”

“…2. ChAdOx1 nCoV-19: 60% [217] 3. BBV152 (Covaxin) vaccinated individuals offer reduced, but significant protection against B.1.617 as compared to B1 strain [214].…”

“…On similar lines, Bernal et al have demonstrated that the effectiveness of BNT162b2 against B.1.617.2 after 2 doses of vaccine reduced from 93.4% with B.1.1.7 to 87.9% with B.1.617.2. However, with ChAdOx1, the 2 doses effectiveness reduced from 66.1% with B.1.1.7 to 59.8% with B.1.617.2[217]. Convalescent sera from infected patients and from recipients of BBV152 (Covaxin) were able to neutralize B.1.617 partially, but the effect was robust as seen with mRNA vaccines…”

Second wave of COVID-19 in India could be predicted with genomic surveillance of SARS-CoV-2 variants coupled with epidemiological data: A tool for future

“…The studies have shown a significant reduction in the neutralization against B.1.617 lineage variants by antibodies received from natural infections and manycurrently used COVID-19 vaccines and multiple monoclonal antibodies (5)(6)(7)(8). Higher transmissibility and immunoescape is being reported for B.1.617.2, which is currently the fastest growing SARS-CoV-2 strain in the Indian population (1,(9)(10). Until December 2020, B.1.1.7 was a dominant strain in the Indian population, although the first cases of B.1.617 lineage had started appearing by then.…”