Covaxin booster dose: What is it? What does govt say about this?
Natural antibodies produced after Covid-19 infection remain effective for 7-12 months, but the effectiveness of vaccine-produced antibodies is not known and the requirement of a booster shot will depend on that.
How long will two doses of vaccines protect you from Covid-19? There is no exact answer to this question as the jury is still out on this. Breakthrough infections or infections after one or two doses of vaccines have also been reported from several parts of the country. While a third booster shot may be the answer to the situation, the government on Tuesday said it will take time to come to a concrete conclusion about the requirement of booster dose while Bharat Biotech is carrying out the trial of its booster shot, which will be the third shot after the two-dose vaccination.
"Booster dose is in the stage of scientific ideation," Dr Balram Bhargava, director-general, the Indian Council of Medical Research, said.
What is the Covaxin booster dose?
In April, Bharat Biotech, the makers of India's Covaxin, got permission from the Drug Controller General of India to conduct trials for a third shot which will be administered as a booster shot. The trial is going on and the first trial result is likely to come in August. The final results are expected by November 2021, reports said. The booster shot might become a yearly thing to keep the immune system to the optimum level.
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Why might a booster shot become crucial?
A booster shot might become crucial in the coming days to fight Covid-19 because emerging variants of the virus are likely to become dominant.
Natural immunity versus vaccine immunity
Dr Bhargava on Tuesday explained that the timeline of vaccine efficacy is yet to be ascertained, while those who have been infected once by SARS-CoV-2 have antibodies for 7 to 12 months. "The application of the booster shot will depend on the knowledge of the efficacy of the vaccine. It is well known that natural antibodies after infection remain for 7-12 months. But the jury is still out to decide how long vaccine-generated antibodies remain effective. Then we can talk about booster shot," Dr Bhargava said. Covaxin's phase 3 trial results are out, which needs to be followed up by probing how long the effect stays, Dr Bhargava said.
Will it be only for people who took the 1st and the 2nd dose of Covaxin?
This is not yet known but in general, booster shots are standalone shots. Sputnik V too has also said it will offer a booster shot to fight against variants.
What has govt said on the booster shot?
Joint secretary of the Union health minister Lav Agarwal said the immediate challenge is to ve vaccinate priority groups at the earliest. "The immediate challenge is to vaccinate the priority age groups; to address vaccine hesitancy. A booster shot is more in a research state. Based on further research, if it comes to a state where booster shots need to be administered in a form of a programme, we will bring that to your notice," Lav Agarwal said.