With Covaxin, antibody response kicks in only after 2nd dose; govt to conduct 25 lakh tests by month-end
With the very first dose of Covishield vaccine, “good levels” of antibodies are produced in the body, but with Covaxin, the adequate immune response is triggered only after the second dose, said Balram Bhargava, Director General of Indian Council of Medical Research (ICMR).
At the weekly Covid update media briefing, Bhargava was responding to a question on the latest protocol released by the ICMR on the duration between two doses of the vaccines. Bhargava said the decision to extend the gap between two doses of Covishield was based on observations made by three committees — Covid Working Group, National Expert Group on Vaccine Administration for Covid-19 (NEGVAC) and National Technical Advisory Group on Immunisation.
According to the current vaccination protocol, the gap between two doses of Covaxin is four to six weeks. However, for Covishield, the government recently extended the gap between two doses to 12-16 weeks from six to eight weeks.
“Vaccines first came on December 15. We are very new and are learning; trials are still on. It is an evolving science. By giving the first dose of Covaxin, you do not achieve much of antibodies, you achieve it after the second dose. With Covishield, antibodies are achieved at good levels,” Bhargava said.
This also puts pressure on manufacturers of Covaxin to make vaccines available for the second dose. Bharat Biotech, manufacturers of Covaxin, is in the process of commencing production in facilities in Kolar, Karnataka and Manjari near Pune, besides Hyderabad. The Covaxin technology has also been transferred to three public sector enterprises, including Indian Immunologicals Limited (IIL), a Hyderabad-based subsidiary of the National Dairy Development Board.