Govt defends Covishield dose gap, says it’s based on scientific evidence

Junking reports over dissent among the medical experts of the Covid Task Force regarding increase in the gap between two doses of Covishield vaccine from 6-8 weeks to 12-16 weeks, the Union Health Ministry on Wednesday cleared the air, saying that the decision of increasing the gap was based on the scientific reason regarding behaviour of adenovector vaccines unanimously. The clarification came on the day India reported 62,224 fresh Covid-19 cases in the last 24 hours, while the daily positivity rate further dropped to 3.22%, according to the Ministry.

According to a statement released by the Ministry, the 22nd meeting of Covid-19 Working Group of the National Technical Advisory Group on Immunization (NTAGI) was held on 10 May, 2021. This Covid-19 Working Group considered a proposal for a change in dose interval for Covishield used under the National Vaccination Policy. “It recommended that ‘based on the real-life evidence particularly from the United Kingdom (UK), the Covid-19 Working Group agreed for increasing the dosing interval to 12-16 weeks between two doses of Covishield vaccine,” the statement from the Health Ministry said.

  This recommendation of the Covid-19 Working Group was further taken up for discussion in the 31st meeting of the Standing Technical Sub-Committee (STSC) of NTAGI which was held on 13 May 2021 under the joint chairpersonship of Secretary, Department of Biotechnology and Secretary, DHR & DG, ICMR. The STSC of NTAGI gave the following recommendation: “As per the Covid-19 Working Group recommendation, a dosing interval of minimum three months between two doses of Covishield vaccine was recommended.”

In both the meetings i.e. Covid-19 Working Group and STSC, no dissent was given by any of the three members who have been quoted in a news report by Reuters, namely, Dr Mathew Varghese, Dr M.D. Gupte and Dr. J.P Muliyil. Further, it is on record that Dr Mathew Varghese has denied talking to Reuters on the issue of his alleged dissent.

Rebutting social media reports related to composition of the Covaxin vaccine, suggesting that Covaxin vaccine contains the newborn calf serum, the Union Health Ministry stated that facts have been twisted and misrepresented in these posts. As per the statement released by the Health Ministry, newborn Calf Serum is used only for preparation/ growth of vero cells. “Different kinds of bovine and other animal serum are standard enrichment ingredients used globally for vero cell growth. Vero cells are used to establish cell lines which help in production of vaccines. This technique has been used for decades in Polio, Rabies, and Influenza vaccines,” the statement read.

These vero cells, after the growth, are washed with water, with chemicals (also technically known as a buffer), many times to make it free from the newborn calf serum. Thereafter, these vero cells are infected with coronavirus for viral growth. The vero cells are completely destroyed in the process of viral growth. Thereafter this grown virus is also killed (inactivated) and purified. This killed virus is then used to make the final vaccine, and in the final vaccine formulation, no calf serum is used. The Union Health Ministry concluded that the final vaccine (Covaxin) does not contain newborn calf serum at all and the calf serum is not an ingredient of the final vaccine product.

Meanwhile, India’s daily positivity rate has been below 5% for nine consecutive days. The active cases have further declined to 865,432. They have gone down to less than 9 lakh for the first time in 70 days. According to the Health Ministry, the national Covid-19 recovery rate has improved to 95.80%. The Covid-19 death toll climbed to 379,573 with 2,542 fresh fatalities in the last 24 hours.