NEW DELHI: A booster dose of Covaxin enhances vaccine effectiveness against Delta and Omicron variants BA.1.1 and BA.2, a study by ICMR and Bharat Biotech said.
The protective efficacy of Covaxin following two and three-dose immunisations against the two variants was studied in a Syrian hamster model (animal model to study human-associated diseases).
“In the Delta infection study, where we compared the protective response between the two and three-dose regimens, we could observe the advantage of the booster dose vaccination in the protection. Although the neutralising antibody levels were comparable among the groups, lung disease severity was found more reduced after the three dose vaccination. The virus shedding and viral organ load were considerably reduced in both the two dose and three-dose immunised animals indicating the vaccine efficacy against Delta variant,” said the study.