Coronavirus vaccines | Adverse events must be reported fortnightly

Covaxin and Covishield haven’t gone through all tests

A dry run for COVID vaccination was performed at a centre in Chennai. File

Both Bharat Biotech and the Serum Institute of India (SII), which have received approval from the Drugs Controller General of India for manufacturing and distributing their COVID-19 vaccines, are expected to submit reports every 15 days on adverse events among those vaccinated, if any, for two months. After this, they would have to submit such reports once a month.

The vaccines developed by both companies haven’t gone through all the required tests, particularly the trials that determine whether the vaccines are effective in Indians. Both companies have been given approvals for “restricted emergency use” though there are further caveats to Covaxin, the Bharat Biotech product, which restrict it to be provided only in “clinical trial mode”.

SII’s vaccine, Covishield, is based on a chimpanzee adenovirus and developed at the Oxford University. U.K. trials showed a 70.4% efficacy with wide variation across subgroups. Covaxin is a whole inactivated virus, the oldest technology in vaccine development, and current scientific reports suggests that it produced a strong immune response in animals but no data yet suggested its efficacy.

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According to the permission notices made public on Monday, Covaxin has to finish its Phase-1, Phase-2 and Phase-3 trials, and submit updated safety, immunogenicity and efficacy data.

Experts express concern

The firms should have a risk management plan in place and must keep providing evidence that their formulations were stable under the required storage conditions.

The approvals notwithstanding, scientists and experts have expressed misgivings , with some saying that the lack of efficacy data for Covaxin means it doesn’t pass a key requirement of vaccine approval.

The government has justified the approval on the grounds that the vaccine employs a whole inactivated virus and therefore had a better probability of providing protection against mutated strains. However, there is no scientific evidence that a such an approach would confer such wide protection.