NEW DELHI: Keeping in view the scientific evidence that has emerged regarding the interval between two doses of a specific COVID-19 vaccine, Covishield, the Centre has directed all the States and Union Territories to increase the dosing interval from 28 days to six-to-eight weeks for better results.
The Ministry of Health and Family Welfare has earlier recommended that two doses of vaccine are 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.
However, on the recommendation of the National Technical Advisory Group on Immunization (NTAGI) and subsequently by the National Expert Group on Vaccine Administration for COVID-19, it appeared that "protection was enhanced if the second dose of Covishield was administered between six and eight weeks but not later than that.
In a letter written by the Union Health Secretary Rajesh Bhushan to the Chief Secretaries of States/UTs today, he mentioned that the recommendations of NTAGI and NEGVAC have been accepted by the Ministry of Health and Family Welfare, Government of India and has thereafter advised the States and UTs to ensure the administration of second dose of COVISHIELD to beneficiaries within this stipulated time interval of 4-8 weeks after the first dose.
It needs to be mentioned here that the revised interval of doses applies only to Serum Institute of India's Covishield - the vaccine developed by Oxford AstraZeneca -- and not to Bharat Biotech's Covaxin.
Bhusan in his letter further urged the States and UTs to instruct the concerned officials accordingly to undertake necessary steps to widely disseminate the message of revised dosing interval amongst programme managers, vaccinators and recipients of COVISHIELD vaccine and ensure adherence of the revised dosing interval.
In India, Covishield and Covaxin have been used in the vaccination drive against the SARS-CoV-2 virus which has caused the COVID-19 pandemic. The first phase of the vaccination drive rolled out on January 16 with healthcare workers to start with and then frontline workers.
On March 1, the second phase prioritized inoculation of people above 60 and those over 45 with other illnesses.
As per reports, over 4.50 crore vaccine doses have been administered across the country since January.