Increase Covishield second dose gap to up to 8 weeks, Centre to States

The ministry of health and family welfare has asked that states nd UTs that the gap between two doses of the Covishield vaccine should be increased from 28 days to six-to-eight weeks for better results. 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 letteron Monday. "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 letter said.

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 current gap between two doses is 28 days, or between four and six weeks.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. Covishield and Covaxin have been used in the vaccination drive that rolled out on January 16 with healthcare workers to start with and then frontline workers.