Inactivated SARS-CoV-2 vaccine (BBV152)-induced protection against symptomatic COVID-19

At present, the delta (B.1.617.2) variant is outcompeting all other SARS-CoV-2 variants as the most predominant variant of concern (VOC) globally, showing substantially higher transmissibility than other VOCs.1 Notably reduced vaccine effectiveness against the delta variant has been reported in real-world studies or case-control studies of the BNT162b2 vaccine or ChAdOx1 nCoV-19 vaccine.2 The surge in breakthrough cases among vaccinated people highlights the extraordinary transmissibility of the delta variant. [...]the report in The Lancet by Raches Ella and colleagues is a welcome advance;3 in a phase 3 trial of an inactivated SARS-CoV-2 vaccine (BBV152) based on an Asp614Gly variant, the authors found a substantial reduction in symptomatic COVID-19. Additionally, BBV152 was well tolerated; the same proportion of participants (12·4%) reported adverse events in the vaccine group (1597 of 12 879 participants) and placebo group (1597 of 12 874), with no clinically significant differences in the distributions of solicited, unsolicited, or serious adverse events between the vaccine and placebo groups, and no cases of anaphylaxis or vaccine-related deaths. The roll-out of BBV152 might ease the ultra-cold chain requirements of other SARS-CoV-2 vaccine platforms, increase the finite global manufacturing capacity, and improve insufficient supply of vaccines which disproportionately affects low-income and middle-income countries.9 The next step for studies of BBV152 should be a focus on monitoring for epidemiological variations in SARS-CoV-2 and the long-term vaccine efficacy against symptomatic COVID-19 and asymptomatic infection to identify whether the vaccine provides ongoing protection when any VOC replacement (other than by the VOCs investigated in this study) has occurred.