Vaccine efficacy. First Covishield jab triggers ‘good levels’ of antibodies

With the very first dose of Covishield vaccine, “good levels” of antibodies are produced in the body, but with Covaxin, 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.

25 lakh tests by month end

At the briefing, Bhargava also spoke about testing facilities. He said the government aims to conduct 25 lakh tests by the end of the month and 45 lakh tests by June. He urged people to go for more rapid antigen tests so that the spread can be prevented by adopting measures like isolation. He said the pace of tests needs to be speeded up till the 5 per cent positivity rate is achieved. “For home testing for Covid-19, three companies are in the pipeline for approval,” Bhargava added.

Lav Agarwal, Joint Secretary, Health Ministry, said eight States have reported more than one lakh active cases, in nine States, they are in the 50,000-100,000 range and 19 States have less than 50,000 active cases. Karnataka and West Bengal remain a concern, with more than 25 per cent positivity rate. Tamil Nadu and some north-eastern States have been asked to continue with containment measures, he added.

Agarwal further stated that since the last nine days, the number of recovered cases has actually surpassed the active cases. He said 69 per cent of the total active cases are limited to only eight States compared with 21 States, where the recovered cases are more than the daily registered ones.

Mucormycosis, an epidemic

On the Centre notifying Mucormycosis as an epidemic, Agarwal said, every case has to be reported by the hospital to the public health network. All the guidelines related to its treatment and management have to be followed, he added.

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