So far, under the largest vaccination drive in India, more than 1.43 crore people have been vaccinated. Among this, 66.69 lakh healthcare workers have received their first dose whereas other 24.56 lakh beneficiaries are done with their second and final jab. India began monitoring the second dose for healthcare workers on February 13 for the ones who completed 28 days after the first dose.
The report citing the WHO’s advisory group SAGE said that an 8-12-week between the doses has been suggested. The Lancet too published some results of a study that indicated that the Oxford-AstraZeneca vaccine (Covishild) can have a higher efficacy when given with a six-week interval. It said that the first dose can offer 76 per cent protection in the three months between the second dose is administered. The report further cited vaccine scientist Dr Gagandeep Kang highlighting that there is evidence around the world that shows an increase in efficacy by 20 to 30 per cent if the interval between two doses is stretched. Kang added that this is something the government should take in consideration on a serious note. “A 20% increase in efficacy when you give it to millions of people is tens of thousands of new infections prevented,” the report quoted Kang as saying.
It is to note that this increasing the intervals can also allow the government to give more doses to people as well as increase vaccine exports. The evidence from the Lancet paper indicates that the first dose is pretty effective for short-term protection. Similarly, scientists at Serum Institute of India also gave a nudge in favour of longer the interval between doses. Dr Shashank Joshi, expert on Maharashtra’s Covid-19 task force also asserted that while a gap of four weeks is reasonable, the gap of 8-12 weeks can be ideal.
However, Prof Sanjay Rai, President, Indian Public Health Association is of the view that the vaccines being precious should be used judiciously. According to him, clinical trials gave the best evidence and gave more weightage when compared to observational studies. Therefore, as per the clinical trials, it was better to give both doses within the time frame that the Centre’s drug regulator has laid down, at least till the time more robust evidence comes in.