Corbevax as heterologous booster along wth Covishield more effective against Covid-19 variants: Research

Panic and worries over vaccine efficacy have arisen after it was found that the Omicron BF.7 variant of the coronavirus caused a surge in cases in China.

So far, India has reported four cases of the BF.7 variant, however, experts believe we don’t need to panic about it just yet but must keep our guard on.

The severity of the BF.7 variant of coronavirus in India may not be as serious as it is currently prevailing in China as India has already developed "herd immunity" a top official of CSIR- Centre for Cellular and Molecular Biology (CCMB) said.

Seeing how the cases are rising in other countries, the government is encouraging people to get their Covid-19 booster shots to be fully prepared for it. Not just the regular booster shot but heterologous vaccine booster shots have been found to be more effective.

Also Read | India doing fine, do not expect surge in cases due to Omicron's sub-variants XBB, BF.7: Virologist

Researchers at AIG Hospitals have published results of a study (titled 'Heterologous Booster Dose with CORBEVAX Following Primary Vaccination with COVISHIELD Enhances Protection against SARS-CoV-2') which show that the indigenous heterologous vaccine booster, Corbevax, when combined with Covishield as primary vaccination, is effective in combating Omicron variants.

Dr D Nageshwar Reddy, Chairman, AIG Hospitals and one of the researchers on board said that the study was done on 250 healthcare workers who had received two doses of Covishield as the primary vaccine regimen not more than 6 months ago.

"The first aspect was to test the safety of this combination. We are extremely happy to report that none of the 250 participants had any adverse events following the administration of Corbevax booster dose. This further cemented our belief that mixed vaccines are absolutely safe," Dr Reddy said.

The second aspect of the study was to measure the antibody response as well as the T-cell (memory cell) response at 30 days and then at 90 days to correctly estimate the overall protection against the circulating Omicron variant and Corbevax as a booster showed higher levels of antibodies at both 30 days and 90 days, the release said.

Also Read | BF.7 not variant of concern in India, claim experts

The study titled was published in journal "Vaccines."

In August 2022, the Covid-19 Working Group of the National Technical Advisory Group on Immunisation (NTAGI) recommended allowing Biological E's Corbevax as a precaution dose for adults fully vaccinated with either Covishield or Covaxin.

So far 92.6 per cent of eligible people have been fully vaccinated against Covid-19 in India. But only 27 to 28 per cent of India's eligible population have taken the booster dose.

Prime Minister Narendra Modi on Sunday asked people to be vigilant and take precautions against Covid-19, as he noted that the virus is spreading in many countries.

(With PTI inputs.)