New Delhi, 24 November
According to the first real-world assessment of India’s indigenous coronavirus vaccine published in The Lancet Infectious Disease journal, two doses of Covaxin are 50 percent effective against symptomatic COVID-19.
Results from an interim study recently published in The Lancet showed that two doses of Covaxin, also known as BBV152, had 77.8 percent efficacy against symptomatic disease and no serious safety concerns.
The latest study assessed 2,714 hospital workers at the All India Institute of Medical Sciences (AIIMS) in Delhi from April 15 to May 15, who were symptomatic and underwent RT-PCR test for COVID detection.
The researchers noted that the delta variant was the dominant strain in India during the study period, accounting for about 80 per cent of all confirmed COVID cases.
Covaxin, developed by Hyderabad-based Bharat Biotech in collaboration with National Institute of Virology, Indian Council of Medical Research (NIV-ICMR), Pune, is an inactivated whole virus vaccine administered in a two-dose regimen 28 days apart .
In January this year, Covaxin was approved for emergency use in India for people aged 18 years and above. The World Health Organization (WHO) added the vaccine to its list of approved emergency use COVID vaccines earlier this month.
The latest study was conducted during India’s second COVID surge and in healthcare workers who were primarily offered Covaxin.
Manish Soneja, Additional Professor of Medicine at AIIMS, New Delhi.
“Our findings provide evidence that the rapid vaccine rollout program remains the most promising route to epidemic control, while public health policies should include additional protective measures, such as the wearing of masks and social distancing.” ,
The COVID Vaccination Center at AIIMS, New Delhi exclusively offered Covaxin to all its 23,000 employees from 16th January this year.
The researchers evaluated the vaccine’s effectiveness against symptomatic RT-PCR confirmed SARS-CoV-2 infection.
Of the 2,714 employees in the study population, 1,617 people tested positive for SARS-CoV-2, the virus that causes COVID, and 1,097 tested negative.
Positive cases were matched with negative RT-PCR tests (controls).
The odds of vaccination with Covaxin were compared between cases and controls and adjusted for occupational exposure to Covid, previous SARS-CoV-2 infection, and dates of infection.
The study found that the vaccine effectiveness against symptomatic COVID was 50 per cent after two doses of Covaxin with a second dose 14 or more days before the RT-PCR test.
The effectiveness of the two vaccine doses remained stable over a seven-week follow-up period, the researchers said.
He said the adjusted vaccine effectiveness of the first dose estimated after seven and 21 days was low, which is in line with the performance of other preventives against the delta variant. PTI