Based on the recommendation from the National Technical Advisory Group on Immunisation (NTAGI) and National Expert Group on Vaccine Administration for Covid-19 (NEGVAC), the central government in March advised states and Union territories to administer the two doses of the Covishield vaccine against the coronavirus disease in a gap of four to eight weeks, instead of the earlier prescribed interval of four to six weeks. This recommendation was based on emerging scientific evidence.
In a statement, the Union ministry of health and family welfare mentioned “Keeping the existing scientific evidence in view, it appears that protection is enhanced if the second dose of COVISHIELD is administered between 6-8 weeks, but not later than stipulated period of 8 weeks.”
The ministry further stated that this revised time interval between two vaccination doses is valid only for Covishield, the Indian-based version Oxford-AstraZeneca AZD1222 vaccine, and not for Covaxin, the indigenously developed shot. Thus, Rajesh Bhushan, the Union health secretary wrote to the chief secretaries of states and Union territories informing them about the decision of the health ministry to go ahead with the recommendations of NTAGI and NEGVAC. Hence, states and UT’s were advised that the administration of the second dose of Covishield has to be systematically inoculated within the stipulated time interval of four to eight weeks post first dose.
Hindustan Times reported, “Bhushan urged the states and UTs to instruct the concerned officials to take necessary steps to widely disseminate the message of revised dosing interval amongst program managers, vaccinators, and recipients of the Oxford vaccine and ensure adherence to the revised gap.”
This recommendation of increasing the time interval between the two jabs will prove advantageous as it will aid hospitals and clinics to provide a larger amount of first doses to people instead f being apprehensive about the number of adequate supplies for second doses for the time being. Thus, there is a high chance that this new practice will help including a larger number in the ongoing second phase of the vaccination drive. In fact, back in December, the Joint Committee on Vaccination and Immunisation (JCVI) in the UK had first suggested delaying the inoculation of second doses of AZD1222 with the aim to speed up the number of first dosages.
Speaking to Hindustan Times, Dr. Gagandeep Kang, one of India’s top vaccine experts, stated, “It is possible (there will be better protection) based on immunogenicity and UK trial efficacy data. The US data indicates good protection with shorter intervals, so real-world monitoring will show how much extending the gap matters.”