The gap between the first and second doses of Serum’s Covishield vaccine can be increased to 12-16 weeks, or three to four months, the National Technical Advisory Group on Immunisation has recommended. But no changes have been recommended in dosage intervals for Covaxin, which remains at four to six weeks.
This is the second time in three months that the Covishield dosage intervals have been widened; in March states and UTs were told to increase the gap from 28 days to six-eight weeks "for better results". At that time the Centre also said: "protection is enhanced if the second dose of Covishield is administered between six and eight months but not later than that.’’
Congress leader Jairam Ramesh flagged the ever-widening interval between doses with sarcasm. ``First, it was four weeks for the second dose, then six-eight weeks and now we are told 12-16 weeks. Is this because there are not enough stocks of vaccines... or because professional scientific advice says so?" he asked. "Can we expect some transparency from the Modi government?" he added.
The changes in interval are based on available real-life evidences, particularly from the United Kingdom, it is claimed. A study published in international medical journal The Lancet on February 19 claimed a 26.2 per cent increase - from 55.1 per cent to 81.3 per cent - if doses were spaced 12 or more weeks apart.
These recommendations will be sent to NEGVA - the National Expert Group on Vaccine Administration - for approval before the changes and suggestions are implemented.
India started the world's largest vaccination drive on January 16 this year in a phased manner with healthcare workers (HCWs) getting inoculated first. The vaccination of frontline workers (FLWs) started from February 2.
The next phase of Covid-19 vaccination commenced from March 1 for those over 60 years of age and for people aged 45 and above with specified co-morbid conditions. India launched vaccination for all people aged more than 45 from April 1.