The United States has decided not to give emergency use authorisation (EUA) to Covaxin, the inactivated whole virus vaccine developed by Bharat Biotech. The decision was communicated to the company’s American partner, Ocugen, even before it submitted an EUA application for the vaccine.
Why did the US not want to give an EUA for Covaxin?
The US is no longer in a situation where it needs to fast-track approvals of Covid-19 vaccines for increased supplies to immunise its people. The country, through its Operation Warp Speed initiative, had invested $18 billion in the development of various vaccines for its population last year. It has already granted EUAs to the Pfizer-BioNTech and Moderna-NIAID mRNA vaccines, as well as Johnson & Johnson’s viral vector jabs. According to Bharat Biotech, the country has managed to vaccinate a “significant” percentage of its population and has also achieved “good” herd immunity.
In this scenario, the US Food and Drugs Administration (FDA) has decided on a new strategy to prioritise its review of EUA requests. The regulator had said in May that it “intends to decline to review and process” EUA requests in cases where it is “not feasible” for it to verify “any one” of the following — the conduct of the clinical trials, the integrity of the clinical trial data, and whether the manufacturing facilities for the vaccine meet “appropriate standards”.
Given the need to address “urgent public health priorities”, the FDA also said it may need to further prioritise among the requests that it received for Covid-19 vaccines. This means that it could decline to review and process EUA requests that came from vaccine makers who had not engaged “in an ongoing manner” with the FDA during the development of their manufacturing process and clinical trials programme.
Does this mean that there is something wrong with Covaxin?
Not really. The US FDA has instead recommended that Ocugen now apply for a full authorisation for the vaccine instead of an emergency approval.
This means that the US FDA will now need “additional information and data”, likely from more human clinical trials, to be convinced that the vaccine is safe, prompts an immune response in its population and has an acceptable efficacy.
However, this is still a setback for Bharat Biotech and Ocugen — it will take longer for Covaxin to be used in the US.
EUA applications for various Covid-19 vaccines have been reviewed and approved within months of the proper data being submitted. However, a full authorisation would mean that Covaxin’s approval may take “up to a year” to receive since it is no longer considered urgent, according to Massachusetts-based vaccine expert Dr Davinder Gill.
Have other countries flagged issues about Covaxin?
Brazil’s health regulator, ANVISA, had rejected an application to give Covaxin a certificate of Good Manufacturing Practices following an inspection of Bharat Biotech’s site in Hyderabad in March. These issues, according to the Brazilian regulator, could potentially risk the quality of the vaccine and, in turn, implied a health risk for those who would use it. While this move was not expected to affect the company’s application for an EUA in Brazil, it would delay its ability to supply the vaccine to the country.
However, on June 4, ANVISA approved the import and use of limited quantities of Covaxin with stringent conditions. According to ANVISA, Bharat Biotech had presented an adequate action plan and had worked on the quality related issues raised earlier this year.
How far have trials of Covaxin progressed?
In India, Covaxin has been tested in phase 1, 2 and 3 human clinical trials involving over 26,000 participants.
However, the vaccine had initially raised red flags for its restricted emergency permission “in clinical trial mode” in January, as it had not generated sufficient data on its efficacy at that time.
Since then, Bharat Biotech has only released media statements claiming that the vaccine’s efficacy is around 78%. Actual published data from the phase 3 clinical trials of the vaccine, which were conducted on over 25,000 participants, is still awaited.
The company expects data on the efficacy and two-month safety of Covaxin to “instantly” reach a preprint server in July after it is submitted to the Central Drugs Standard Control Organization (CDSCO). Peer review of this information is expected to take another 2-4 months, according to Dr Raches Ella, Bharat Biotech’s Covid-19 vaccines project lead.
If I received Covaxin, does that mean I will not be allowed in the US?
If you are not restricted from travelling to the US in the current circumstances, the country requires a negative RT-PCR test for you to be able to board a flight.
If you are a student looking to attend a university in the US in the fall, it is unlikely that having received two doses of Covaxin will stop you from being able to enter the country. Several universities have allowed international students to “restart” their immunisation upon arrival in the US with one of the approved vaccines that are available in the country.
The vaccine is still going to be reviewed by the US FDA under a standard approval process that may take time. In the meantime, Bharat Biotech has also submitted an application for an Emergency Use Licence from the World Health Organization, which it expects will come between July and September this year.
It is likely that this would ease any potential restrictions that could arise in the US for those who have been vaccinated with Covaxin.