New Delhi: Two doses of COVID-19 vaccine Covaxin (BBV152) are 50 per cent effective against symptomatic COVID-19 disease, according to the first real-world assessment of the COVID-19 vaccine published in the Lancet Infectious Diseases journal.
The study assessed 2,714 hospital workers at the All India Institute of Medical Sciences (AIIMS) in Delhi, from April 15-May 15, who were symptomatic and underwent RT-PCR test for COVID-19 detection.
"2714 symptomatic tested participants remained, of whom 1,617 tested positive for SARS-CoV-2 and 1,097 tested negative," the study said.
"The unadjusted effectiveness of two doses of BBV152 against symptomatic RT-PCR-confirmed SARS-CoV-2, with an interval of at least 14 days between administration of the second dose and day of testing, was 53 per cent. After adjustment, the effectiveness was estimated to be 50 per cent. The adjusted effectiveness of two doses administered at least 28 days before testing was 46 per cent and administered at least 42 days before testing was 57 per cent," it said.
In January this year, Covaxin was approved for emergency use in India for people aged 18 and above. The World Health Organization (WHO) added the vaccine to its list of approved emergency use COVID-19 vaccines earlier this month.
Head of Medicine at AIIMS Delhi, Professor Naveet Wig said that the results demonstrate the effectiveness of BBV152 against symptomatic RT-PCR confirmed SARS-CoV-2 in the setting of a huge surge dominated by the delta variant.
"Given the long safety record and easy scalability of the platform on which it is developed, it is emerging as an important tool in the fight against COVID. It is important not to get fixated with varying effectiveness figures obtained from different studies under different conditions," he said.
"Addressing vaccine hesitancy by the availability of a safe and effective vaccine and achieving universal coverage at a rapid pace are crucial to controlling the pandemic. Results also reinforce the need for continued adherence to non-pharmacological interventions like masks, social distancing and avoiding large public gatherings," he said.