BENGALURU: Covishield vaccine had higher antibody response compared to Covaxin during the pandemic, according to a study by a consortium of 11 institutions led by scientists from the National Centre for Biological Sciences, Bengaluru.
In all, 691 people aged between 18 and 45, mostly from Bengaluru and Pune, were part of the study.’Immunogenicity of SARS - CoV-2 vaccines Covaxin and Covishield in seronegative and seropositive individuals in India: a multicentre non-randomised observational study’ was published in Lancet Regional Health Southeast Asia journal in February.
The researchers compared the immunogenicity of Covishield and Covaxin, which were the two primary Covid-19 vaccines, widely used in India.Compared to the pre-vaccination baseline, both vaccines elicited statistically significant seroconversion.
The study was conducted between June 30, 2021 and January 28, 2022. It was a non-randomised and laboratory blinded study, where the participants received either two doses of Covaxin or Covishield as per the vaccination policy. The vaccination records were monitored and immune responses noted at different intervals.
Dr Mangaiarkarasi Asokan, former programme head, VISION (Vaccine Immunology Studies-Indian Outbreak-response Network) and lead author of the study, said Covishield demonstrated more robust immune response compared to Covaxin in leveraging a virus vector to deliver the spike protein of coronavirus.
Also, the response to Covaxin was variable, particularly among those inoculated before the emergence of the omicron variant. Covishield consistently exhibited higher levels of antibodies against various virus strains compared to Covaxin, suggesting its potential superior protection against variants such as omicron.
Prof Satyajit Mayor, scientist, NCBS-TIFR (Tata Institute of Fundamental Research), said the study was conducted at the peak of the pandemic and reflected a collective sentiment to bring evidence-based decision-making to the outcomes of vaccination on the Indian population, using two indigenous vaccines that were rolled out quickly. Finally, the outcome of the study, where the Covishield vaccine was shown to outperform Covaxin in all respects, should have important implications to strategise future vaccination drives.