Bharat Biotech’s Covaxin Was 50 Percent Effective in Real-World Study

India-based Bharat Biotech’s COVID-19 vaccine, Covaxin (BBV152), was just 50 percent effective in preventing infections among hospital employees in India who received the recommended two doses.

The results of the real-world study differ sharply from the vaccine’s pivotal phase 3 data, which found an effectiveness rate of 77.8 percent.

Several differences in the study population and setting may account for the disparity, said the new study’s primary investigator Devashish Desai, of the All India Institute of Medical Sciences in New Delhi, and his colleagues, who reported their findings in The Lancet.

As healthcare workers, all subjects were considered high-risk. And the study was also conducted during India’s peak COVID-19 surge, when 35 percent of the population was testing positive for the virus. The infections were largely caused by the Delta variant, Desai noted.

The case-control study comprised 2,136 fully vaccinated subjects tested for COVID-19 infections in the facility; half of these were symptomatic and half were not.

Although the protection against infection was much lower in this study than previously found, the vaccine does appear to offer substantial protection against severe disease (93.4 percent), symptomatic infection (63.6 percent) and delta variant infection (65.2 percent).

Covaxin was initially given only to frontline health workers, police and emergency responders in India. Last March, the vaccine was approved for all Indian residents older than 60 years and for people aged 45-60 with medical comorbidities. It’s now offered to any adult aged 18 years or older.

The World Health Organization (WHO) granted an emergency use listing to Covaxin in early November, allowing the shot’s inclusion in the WHO-backed COVAX vaccine-sharing program (DID, Nov. 4).

Read the full study here: bit.ly/3r7TyLG. — Michele G. Sullivan