Covaxin Approved as Backup in Case of Virus Surge: AIIMS Director

Phase III trials of India’s indigenous vaccine are still ongoing, with recruitment not yet completed. 

Updated
COVID-19
4 min read
Bharat Biotech's COVID Vaccine Approval: What is the approval for? Is the vaccine safe?
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The surprise conditional approval of Bharat Biotech's Covaxin by India's highest drugs regulator DCGI has raised several questions. Currently, phase III trials of India's indigenous vaccine are still ongoing, with recruitment not yet completed. Only preliminary animal trial and phase 1 data is available in public domain that indicates 'robust immune response.' The data has not been peer reviewed.

While the approval is conditional, 'for public interest out of abundance of precaution,' it still raises questions on what was the hurry. The Quint asks all this and more to Dr Randeep Guleria, director, All India Institute of Medical Sciences (AIIMS).

Dr Guleria, Bharat Biotech’s Covaxin approval appears to be based on initial animal trial data, interim analysis of phase 1 and 2 trials. This data cannot possibly indicate safety and efficacy which requires phase 3 data. I wanted to understand from you on what basis did the SEC recommend the vaccine?

If one reads what’s been shared, the vaccine has been approved for ‘emergency situation out of abundance of precaution.’ I think because of what is happening in the US, UK and Europe, if India has a surge in cases, and an emergency situation arises, we will need more doses and there is no drug available, then this vaccine may be made available. Otherwise it will be Covishield that will be used.

Whatever data that was shared was reassuring as far as safety was concerned. The safety data was robust, efficacy data is still needed to be proven, but the committee felt that in case an ‘emergency situation’ arises, an alternative to Covishield can be made available in clinical trial mode.

The idea seems to be to give them a green signal to start stockpiling the vaccine. Hopefully in next 4-6 weeks more data will come in that will prove efficacy as well.

I see this as a back up rather than a front-end vaccine. I don’t think they’ll start using it till more data is available.

The question being asked is, what was the hurry? Why not just wait a month or two, get this data in, and then give a similar approval as Covishield?

It will happen in a month’s time, but if in a couple of weeks time new cases are touching one lakh, then you are in a situation where you want to vaccinate as many people as possible, and that is not possible with Covishield alone. This remains a backup till then.

This is what happened in the UK, where the cases went up by nearly 70 percent due to the new mutant variant, and a panic situation was created where they are even considering a schedule where the second dose is delayed. The type of clearance they’ve given Serum Institute, will happen only after 4-6 weeks for Bharat Biotech.

Covaxin is an inactivated vaccine, and these are generally considered safer, but without a robust data, are we taking a risk with people’s lives?

This is a whole virion inactivated vaccine. The theory is that the chances this will act against the mutant variant is higher, compared to a viral vector vaccine, and therefore it is worthwhile to keep a stockpile ready as backup.

Covaxin is an indigenous vaccine and made in collaboration with Indian Council of Medical Research (ICMR) and National Institute of Virology (NIV). While a pharma major may be under no obligation to share the data with the public, but does this responsibility of putting the data out in public not extend to ICMR and NIV?

The data should be published, it should be in public domain. Whatever data you have, you should publish it in good peer-reviewed journals because that gives strength and confidence to everyone. I hope they will publish it in due course. Everyone should have a chance to look at the data critically, it inspires confidence.

For Covishield, Dr Guleria, do we know what dosage and schedule has been approved? The DCGI in the statement mentioned 70.4 per cent efficacy, but that efficacy arrives from combining two very different trial data from Brazil and the UK where the efficacy ranged from 62 percent to 90 percent.

So currently India is sticking to two full doses rather than a half dose and one full dose combination, because that data is still not robust enough for us to adopt it. Also our trials in India were done on two full doses. Secondly, since we are not in the same situation as the UK, we are sticking to a schedule of 28 days between doses. I don’t think currently the government and the regulators are looking at the same schedule as the UK.

In the UK, there was a suggestion of mixing two vaccines, for eg, if one received an oxford vaccine first, you may get a Pfizer vaccine as the second dose. Is that wise? Considering these are all very different vaccines?

I currently don’t think it is safe to mix two vaccines, because the booster effect is basically looking at the same mechanism which has worked in the first dose. We need more data for that. Unless we have at least some studies that have looked at a schedule like this, it is a bit premature to consider this.

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