Covishield shows 60-70% efficacy; Modi to visit Serum Institute on Saturday

Interim data from the Indian arm of Oxford-AstraZeneca vaccine candidate AZD1222 (also known as Covishield) has shown the lowest efficacy results of 60-70 per cent. Pune-based Serum Institute of India (SII) is conducting phase-3 trials on 1,600 Indian volunteers, with people in the know indicating that these trials are being done with two full doses. So far, they added, trials have shown efficacy of 60-70 per cent. If the primer-booster regimen (half dose followed by a full dose) has to be adopted, SII would need to conduct additional tests.

On the Oxford-AstraZeneca vaccine, an SII spokesperson said: “The AstraZeneca-Oxford vaccine is safe and effective. Even the lowest efficacy results are at 60-70 per cent, making it viable. That said, varied age groups with different dosage forms will result in slight variations and efficacy. We must be patient and not panic.” 

SII is unlikely to announce any interim data from the trials here. It will wait to compile and analyse data, before sharing it with the Indian regulator. Oxford and AstraZeneca are also expected to submit their global trial data to the Indian drug regulator, with people in the know indicating that recent developments will not delay the timeline.

As for India, SII said the trials were running ‘smoothly’. “The Indian trials are running smoothly, with strict adherence to necessary processes and protocol. So far, there has been no concern. However, we are going through the data that is available, and will make further statement, if needed,” said the spokesperson. People in the Central Drugs Standard Control Organisation (CDSCO) said the regulators will not go by announcements made by vaccine makers (whether in India or abroad) citing interim data.

“Efficacy data announced is based on interim data, and these have not been yet published in peer-reviewed journals. Companies can make any tall claim. Regulators will analyse the data in detail, and not go by press conferences. We will take a call keeping in mind all scientific parameters as well as the safety and efficacy of the vaccine,” said an official.

Following the announcement this week by AstraZeneca and the University of Oxford — regarding efficacy of their candidate — they now face mounting questions on their trial results after acknowledging a manufacturing error.

While this announcement showed that their shot was, on an average, 70 per cent effective (in a late-stage study), the scant details released by the UK partners have sparked worries, with some expressing doubts about whether US regulators will clear it.