At a time the scarcity of Covid photographs in India has slowed down vaccinations, the central authorities’s new technique is to check mixing two vaccines collectively and in addition the effectiveness of a single dose of Covishield.
“India might quickly begin in few weeks testing feasibility of a routine that mixes two completely different doses of Covid vaccines to see if it helps increase immune response to virus,” said Dr N K Arora, chairman of Covid-19 working group under National Technical Advisory Group on Immunisation (NTAGI).
Meanwhile, Banaras Hindu University researchers have claimed a single dose of vaccine is enough for Covid recovered patients. “We studied the effect of vaccine on Covid recovered and non-infected people. Antibodies in recovered people developed in first week,” Prof Zoology Dept BHU Gyaneshwer Chaubey said.
“While 90 per cent of non-infected people developed antibodies after 3-4 weeks, recovered people developed antibodies after first dose. By giving single-dose to recovered people, we can overcome vaccine shortage. We’ve also written a letter to PM in this regard,” the professor said.
But the reason behind this thought is lost on health experts and epidemiologists. “No, not a good idea at all. There is no data to suggest one dose has proven efficacy to offer sufficient protection against mortality/serious illness at the population level,” said Professor Giridhar Babu, Epidemiologist, Public Health Foundation of India and advisor to the Covid task force state of Karnataka.
“Available evidence suggests that two doses of vaccines are effective in preventing deaths. No efficacy gets proved by looking at the antibody levels that too at the individual levels, they are only at the population level. With respect to one dose, no trial has given any evidence that it will be sufficient in preventing deaths or serious illness. We need to cover both doses especially for the vulnerable population. In the given time frame if we are unable to cover two doses, maybe we can cover one dose, but the second dose needs to be given sometime later at least in the 12 week period when the efficacy is around 84 per cent,” said Dr Babu.
Dr Aviral Vatsa of the NHS, Scotland said, “This is scientifically wrong. Period. In fact, single dose gives some degree of protection only, and the second dose actually makes the protection levels above 60-70 per cent and even more in certain cases. Lack of vaccine doses should be dealt with differently.”
C S Pramesh, Director, Tata Memorial Hospital, mentioned there is no such thing as a information to recommend that one dose of Covishield is sweet sufficient to guard from Covid-19.
The concept of single-dose vaccination comes at a time when the UK has determined to cut back the dosing interval of the AstraZeneca vaccine to eight weeks to make sure the complete safety of its susceptible inhabitants. India has accomplished the reverse by deciding to extend the dosing interval for Covishield to 12 weeks, citing proof from the UK.
Recently, because the UK seems ahead to an unlock in June, a examine offered to the federal government emphasised that two doses offered higher safety towards particular variants of the virus than a single dose.
Covishield is the Indian model of the AstraZeneca-Oxford University vaccine produced by Pune-based Serum Institute of India and is probably the most used vaccine in India at present. Covaxin manufactured by Hyderabad-based Bharat Biotech is the second most used vaccine.