Countries such as the UK and Canada that are also using the vaccine developed by AstraZeneca and Oxford have extended the interval between the two doses to as long as four months. Serum Institute of India manufactures this vaccine in India and exports it to many markets.
India has decided to continue with the interval of 4-6 weeks for the administration of the two doses of the Covishield vaccine, despite new evidence suggesting better efficacy when the second booster shot is given after 8-12 weeks.
Countries such as the UK and Canada that are also using the vaccine developed byAstraZenecaand Oxford have extended the interval between the two doses to as long as four months. Serum Institute of India manufactures this vaccine in India and exports it to many markets.
A new study that was published in the medical journal Lancet on March 6 has shown that a longer interval between the doses provided a higher efficacy (as much as 90%) compared with a six-week gap. Those vaccinated are protected against the symptomatic Covid-19 despite the longer dosing interval.
However, the National Expert Group on Vaccine Administration for Covid-19 (NEGVAC), which met this week, decided to continue with the same dosage interval of four-six weeks for both Covishield and Covaxin in India.
The World Health Organization recommends an interval of six weeks between the shots.
“The NEGVAC reviewed the matter both from the scientific and programmatic point of view and decided to continue with the same regime,” a senior government official said.
Earlier, the National Technical Advisory Group on Immunisation (NTAGI), the government’s advisory committee which had met on February 19 to review the vaccine dosage interval, had not felt any need to extend it, given that India has enough vaccine supplies and recommended the NEGVAC to continue with the same regime, government officials told ET.