COVAXIN

What is Covaxin?

It has been developed by the company Bharat Biotech India (BBIL) in collaboration with ICMR’s National Institute of Virology (NIV). It is an “inactivated” vaccine — one made by using particles of the Covid-19 virus that were killed, making them unable to infect or replicate. Injecting particular doses of these particles serves to build immunity by helping the body create antibodies against the dead virus, according to BBIL.

News about Covaxin

Earlier this week, Bharat Biotech announced that it had developed a vaccine against the novel coronavirus, named Covaxin, together with the Indian Council of Medical Research (ICMR) and the National Institute of Virology (NIV), Pune. The company had also received permission from the Drug Controller General of India (DCGI) to begin human trials, expected to commence in August.

Bharat Biotech is a reputed drug manufacturer that delivers four billion doses around the world for infections like rotavirus, hepatitis, Zika, Japanese encephalitis and others. However, its claim that Covaxin is indigenous – advanced, among others, by managing director Krishna Ella – raises some doubts.

According to Bharat Biotech, Covaxin is an inactivated vaccine developed from an Indian strain of the novel coronavirus isolated by NIV. No further information has been provided, especially about the nature of the vaccine or how it was developed. There have been no prior announcements either about when the process of developing such a vaccine was begun.

ICMR transferred the strain NIV had isolated to Biotech Bharat on May 9. The company published its press release on June 29. So there were only 50 days in between, during which time the company should have developed the inactivated vaccine, conducted preclinical animal trials (with mice and hamsters, according to the company), and sent its reports to be evaluated and approved by DCGI. Although ICMR had promised to expedite the process, animal trials with mice typically take at least three months to conclude.

A related issue is that animal trials for COVID-19 can only be conducted with hACE2 transgenic mice, as ‘normal’ mice can’t get infected with the novel coronavirus. These mice need to be shipped from the US, Europe or China.

These issues therefore raise concerns about whether Bharat Biotech could really have proceeded to the human-trials phase of vaccine development within only 50 days of receiving the inactivated virus from NIV.

Collaboration with US company

Bharat Biotech has currently invested in two other vaccines: CoroFlu in collaboration with FluGen Inc. and the University of Wisconsin-Madison, and an inactivated rabies vaccine vehicle for coronavirus proteins developed along with Matthis Schnell, director of the Jefferson Vaccine Centre (JVC), Pennsylvania. The latter is of interest.

On May 20, Bharat Biotech announced its collaboration with JVC as well as the license it had received to conduct clinical trials, and to produce and deliver vaccines in 80 countries excluding the US, Europe and Japan. On April 7, JVC announced a promising vaccine candidate named Coravax.

Coravax uses an inactivated rabies vaccine to carry the spike protein of the novel coronavirus. The spike protein attaches to a host cell and causes an infection, so experts expected this vaccine to trigger a good immune response on the body’s part. Schnell corroborated this response following preliminary tests with animals. Schnell added that JVC would need one more month to complete follow-up studies.

Bharat Biotech hasn’t shared any technical details of Covaxin. But based on what we already know, there appears to be room for the possibility that Covaxin is Coravax by another name – and by another viral strain. And even if the vaccine is wholly indigenous, the timelines for the animal trials don’t line up.

When does ICMR plan to launch it?

Aiming to make it available for public use by August 15, Bhargava wrote to the 12 trial sites to ensure “all” clinical trials were conducted by then. While BBIL’s application with the Clinical Trials Registry of India (CTRI) shows it plans to complete enrolment of trial participants by July 13, Bhargava has directed the sites to complete enrolment by July 7.

Is this even achievable?

A vaccine usually goes through three phases of human trials. The Central Drugs Standard Control Organization has given approvals for phase I and II trials so far. According to details from CTRI, BBIL in its application estimated phase I and II trials to take a year and three months, including at least a month for phase I alone.

Experts have questioned how all three phases can be concluded within a month and a half. “I would find it very surprising if it is done. Even the most ambitious companies in the world that are in more advanced stages of development for their Covid-19 vaccines have a longer time-frame. Even having all the trial results, with safety and efficacy data, by August 15 is difficult. This raises several questions,” said Dr Anant Bhan, Researcher, Global Health, Bioethics and Health Policy.

While vaccine trials can be fast-tracked, it still takes over a year to launch the product, experts said. In a pandemic, emergency-use approval can be given if data from the first two trial phases is compelling enough, said an expert on condition of anonymity. This would allow the launch without the third phase being conducted, but this approval would likely be given with riders to submit additional data and adverse event reports.