How quickly can Bharat Biotech's coronavirus vaccine hit the market?

Fifty-two days after the Indian Council of Medical Research (ICMR) announced its partnership with Bharat Biotech to develop a fully indigenous vaccine, the Hyderabad-based company has said that the vaccine candidate COVAXIN has received regulatory approval for accelerated human clinical trials.

COVAXIN, which is a fully indigenous vaccine, has been developed using a strain isolated at ICMR's National Institute of Virology (NIV), Pune. Bharat Biotech has received the approval for accelerated phase 1 and 2 human clinical trials of the vaccine candidate.

Now, the question is how long will it take for the vaccine to be ready for use. Let's understand the duration of different stages of vaccine development to get an idea:

As per global average, a drug candidate in a lab typically takes 12 years to hit the market; a vaccine takes 8-10 years. They are put through different phases of clinical trials which take years.

• Phase 1 is on 1,000-3,000 patients and takes 2 years
• Phase 2 is on 1,000-3,000 patients and takes 2 years
• Phase 3 is on 15,000 to 30,000 patients and takes 3-5 years

But that's not it. Regulators sometimes demand bigger surveys before clearing the drug or vaccine, which can further delay the process.

However, in situations such as the ongoing pandemic, it's in everybody's interest for things to move fast in vaccine development. So, we have what's called accelerated trials.

Under the accelerated trials:

• Phase 1 is for safety studies and conducted on 50 to 500 people. It takes up to 4 months.
• Phase 2 is for dosage. It's conducted on 500 to 1,000 people and takes another 4 months.

But, to make the vaccine development process even faster, these 2 phases will now happen together in the case of COVAXIN, and other coronavirus vaccine candidates around the world.

• Phase 3 is for vaccine efficacy in mass trials for different genetic types. It depends on disease prevalence and the recommendation of the scientific advisory committee of the government. The phase 3 could cover anywhere between 1,000 to even 50,000 people. The time taken depends on the dosage, and can be anywhere between 4 months to up to 2 years.
• Phase 3 also depends on the negatives that result from the first two phases. Fewer negatives mean fewer people in Phase III. More the negatives, more people need to be covered.

After these three phases, the trial results are presented to regulator for approvals and validation which could take up to 6 months even in accelerated trials.

Bharat Biotech isn't committing a timeline, but based on the above processes, and if the vaccine does not fail at any stage, the earliest COVAXIN could hit the market is late 2021.

Meanwhile, there are close to 150 vaccines under different stages of development, according to the World Health Organisation. Among them, there are about 10 or so, which are in a relatively advanced stage of development. The WHO has listed these vaccine candidates on different stages of development as of June 29:

• University Oxford/AstraZeneca vaccine candidate is in phase 3 trial. Indian company Serum Institute will manufacture the vaccine.
• CanSino Biological Inc./Beijing Institute of Biotechnology has two candidates in phase 2 and in phase 1.
• Wuhan Institute of Biological Products/Sinopharm is in phase 1/2 combined.
• Moderna/NIAID has two candidates in Phase 2 and 1.
• Sinovac has also a candidate in phase 1/2.
• Novavax has also a candidate in phase 1/2.
• BioNTech/Fosun Pharma/Pfizer also has a candidate in phase 1/2.
• There are eight others globally in phase 1 and the rest in pre-clinical stage, including Indian companies like Zydus Cadila, Biological E, Indian Immunological. Other global companies that have Indian connection, include Sanofi along with GSK, which also has a candidate in pre-clinical stage.

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