Shortfall in Phase-III Covaxin trial target, can delay rollout: AIIMS doctor (IANS Special)

New Delhi, Dec 18 (IANS) The rollout of Covid-19 vaccine by Bharat Biotech for the general public may get delayed as the All India Institute of Medical Sciences (AIIMS), where its Phase-III human clinical trial is underway, is struggling to find takers of the trial shots, the official heading the project told IANS.

While speaking to IANS, Sanjay Rai, the doctor who is the principal investigator (PI) of Covaxin trial, stated that there are chances that the vaccine may get delayed for the public use if the participation of subjects in the trial does not go up.

"The rollout would definitely get delayed if the participation in the trial remains low and does not meet the targeted sample size.

"With low sample size, the credible data on efficacy will not be achieved," he said.

"However, it is completely the prerogative of the regulatory authority to decide whether and when to approve a vaccine," Rai said.

The enrollment of candidates for undergoing Phase III human clinical trials of Bharat Biotech's Covid-19 vaccine at AIIMS has reported a mammoth refusal rate.

Rai, who also heads the Department of Community Medicine at AIIMS told IANS that in the Phase-III trials, around 80 per cent refusal rate was seen in the participation, whereas it was around 8 per cent for the earlier Phase I and II.

In Phase I and II, the clinical site had enrolled more than 800 candidates cumulatively while the target for phase III is around 1,500.

Rai stated that the institute is way behind the committed target. "We had committed around 1,500 participants till December end. However, only 300 recruitments have taken place so far. The recruitment of the volunteers is way behind the committed target," he said.

Two days ago, results of the Phase I trial of Covaxin were published in a medical journal which showed that the vaccine was found safe and well-tolerated in all dose groups.

The interim results were published in pre-print format on MedRxiv and found that the vaccine generated an immune response with one adverse event during the trial, which was found to be unrelated to the vaccine. The phase I trial was done on 375 participants.

The Phase III trials of Covaxin are meant to be conducted upon a total of 25,800 participants across 25 different sites in India.

Commenting on the results of Phase I trial, Rai said it reflects that the vaccine is "safe and has negligible side-effects".

"Covaxin also induced immune response. The immediate safety concerns have been addressed by Phase-I results," he added.

Bharat Biotech had applied for Emergency Use Authorisation (EUA) of Covaxin along with Astrazeneca and Oxford university developed and Serum Institute of India manufactured Covishield to the Drug Controller General of India (DCGI).

Their application is pending for approval after the Subject Expert Committee (SEC) found inadequate safety and efficacy data of the vaccines.

The SEC has recommended furnishing further safety and efficacy data to Bharat Biotech and SII to receive the EUA.

--IANS

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