The gap between two doses of the Covishield vaccine should be increased from 28 days to six-to-eight weeks for better results, the government has written to states and Union Territories.
The instruction has gone out in the middle of round two of nationwide vaccinations, in which people above 60 and those over 45 with other illnesses are being inoculated.
The revised interval applies only to Serum Institute of India's Covishield – the vaccine developed by Oxford AstraZeneca — and not to Bharat Biotech's Covaxin, the centre said in its letter today, reported NDTV.
The current gap between two doses is 28 days, or between four and eight weeks.
The letter issued by the centre said, "In view of the emerging scientific evidence, the interval between two doses of a specific COVID-19 vaccine, Covishield, has been revisited by the National Technical Advisory Group on Immunization (NTAGI) and subsequently by National Expert Group on Vaccine Administration for COVID-19."
The centre's letter said it appeared that "protection was enhanced if the second dose of Covishield was administered between six and eight weeks but not later than that.
The Health Ministry had earlier said two doses of vaccine needed to be taken 28 days apart to complete the immunisation schedule. The "protective levels of antibodies" were generally developed two weeks after receiving the second dose, the ministry had said.
More than 4.50 crore vaccine doses have been given across the country since January.
