Covaxin 50% Effective Against Delta Variant: Real-World Study

The efficacy of Covaxin in preventing symptomatic Covid-19 is 47%-50%, according to real-world data derived from infections in a group of over 2,700 hospital workers when India was hit by the Delta variant, according to a study published on Tuesday in the Lancet Infectious Diseases journal.

- Rhythma Kaul

NEW DELHI: The findings are based on the study conducted between April 15 and May 15, at the height of India's second wave of infections this year. Covaxin in clinical trials had an estimated efficacy of 65% when the more infectious Delta variant was taken into account.

Covaxin in clinical trials had an estimated efficacy of 65% when the more infectious Delta variant was taken into account.

All vaccines have shown to be less effective when infections have been caused by the more transmissible variant of the SarsCoV-2, and the latest report underscores the higher odds of catching Covid-19 during an active wave and among healthcare workers.

According to a study published in the New England Journal of Medicine, the efficacy of the Pfizer-BioNTech vaccine dropped from 93.7% to 88% and that of the AstraZeneca vaccine (as the Covishield shot is known in markets where the British pharma company makes) from 75% to 67% when protection against Alpha and Delta variants were compared. It is likely those numbers may have reduced further for high-risk groups such as hospital workers.