Widening Covishield gap - did the govt rely on proper evidence and follow due process?

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The government's decision to increase the gap between two doses of the Covishield vaccine to 12-16 weeks was taken unanimously, an official statement said after media reports alleged dissent by some members of a technical panel.

According to media reports, at least three members of the Standing Technical Sub-Committee (STSC) of National Immunization Technical Advisory Group (NTAGI) had expressed dissent on increasing the gap between doses.

The government rejected the reports. "In both the meetings COVID-19 Working Group and STSC, no dissent was given by any of the three members who have been quoted in a news report of Reuters, namely. Dr Mathew Varghese, Dr MD Gupte and Dr JP Muliyil, further it is on record that Dr Mathew Varghese has denied talking to Reuters on the issue of his alleged dissent," the government said.

Here is an explainer on why the decision to widen the gap between two doses of Covishield is becoming controversial, on what basis the decision was arrived at, and what process was followed.

Why did the government widen the gap between doses? When the government took the decision in mid-May to expand the interval, COVID-19 was killing about 4,000 deaths per day. Many believed that that the gap was increased to tide over the shortage of COVID-19 vaccines in the country and save more lives.

The chair of covid sub-committee of NTAGI Dr N.K Arora denied the decision has anything to do with shortage of vaccines. He maintained that the decision to increase the interval was based on evidence in the UK.

“We have not increased the dosing interval because there was a shortage of doses," Arora said at that time.

Data of AstraZeneca vaccine efficacy suggests that in participants who had an interval of 12 weeks or more between the two jabs, the efficacy increases to 81.3 percent. Overall efficacy against symptomatic COVID-19 after more than 14 days after the second dose in the UK and Brazil is at 66.7 percent. Based on this information, the UK government extended the gap to three months. It was able to vaccinate more people, with limited supplies of the vaccine.

The decision by the government coincided with Public Health England's study that pointed out that the protection offered by one dose of the vaccine could be considerably lower at 33 percent, particularly against the B.1.617 or Delta variant and not 65-85 percent that was estimated earlier. This prompted the UK government to reduce the gap between the two doses of vaccines for people over 40 from 12 weeks to 8 weeks. This led to a growing chorus of experts demanding the government to review their decision and go back to the previous regimen of 8-12 weeks interval.

"Delta variant - likely to escape one vaccine dose. Twice more likely to get you into hospital," said Dr. Arvinder Singh Soin, leading surgeon and Chairman, Medanta Liver Transplant Institute tweeted.

"But two doses almost certain to prevent hospitalization. We must shorten the 12-16 week dosage gap for Covishield without further ado," he added.

There were also allegations that the increasing the gap was a political decision, camouflaged as a scientific one. But the government vehemently denied these allegations.

What process was followed? The government's decision on May 13 to widen the gap between two doses of Covishield to 12-16 weeks was based on NTAGI recommendation. NTAGI's COVID-19 Working Group took the decision to expand the interval on May 10. This decision was further deliberated by the Standing Technical Sub-Committee (STSC), which endorsed COVID-19 Working Group decision. Both COVID-19 Working Group and STSC function under NTAGI.

According to the minutes of the meetings, STSC met on May 13, 2021 under the joint chairpersonship of Renu Swarup, Secretary, Department of Biotechnology and Balram Bhargava, Secretary, DHR & DG, ICMR.

Both COVID-19 Working Group and STSC function under NTAGI.  NTAGI members and invited attendees are made to sign confidentiality agreements at the start of meetings.

Is there a dissent recorded? The minutes of the May 28 meeting of the NTAGI's COVID-19 Working Group neither records any dissenting notes by any member nor any recommendations. There was no information about the crucial NTAGI's STSC meetings which met five times and took up several COVID vaccine issues including interval between doses.

The members in STSC are Dr JP Muliyil, Professor, CMC Vellore, Dr Gagandeep Kang, Professor CMC Vellore, Dr. Indrani Gupta, Professor Institute for Economic Growth, Delhi, Dr. Rakesh Aggarwal, Director, JIPMER, Puducherry, Dr. Mathew Varghese, Head of the Dept, Orthopaedics, St.Stephen’s Hospital, New Delhi, Dr. Satinder Aneja, Professor Sharda University, Noida, Dr. Neerja Bhatla Professor AIIMS, New Delhi, Dr. M D Gupte, Former Director, NIE, Chennai, Dr. Y K Gupta Principal Adviser THSTI-DBT, Dr. Arun Aggarwal Professor, PGIMER, Chandigarh and Dr Lalit Dhar, Professor, Virology, AIIMS, New Delhi