WHO has said that a COVID-19 vaccine should at least show the efficacy of 50 percent in mandated trials and Covaxin clears this requirement with its latest Phase-3 results
With 77.8 percent efficacy rate and at least over 2.5 crore doses administered so far, Covaxin is up for evaluation by WHO as India’s only indigenously created COVID-19 vaccine eyes an emergency use listing. Clearing WHO’s licensing process will be a shot in the arm for a jab that has dealt with its share of uncertainty and controversy even as it became a key component of India’s
Why is the meeting with WHO crucial?
The World Health Organisation (WHO) has extended its emergency use nod to a total of seven manufacturers worldwide. Of these, three are for those producing the Oxford-AstraZeneca vaccine with the submissions linked to different national-level regulators, including one by the Serum Institute of India after Covishield was cleared by the Drug Controller General of India (DCGI). The other vaccine makers are Pfizer-BioNtech, Moderna, Janssen (which is making the single-shot Johnson & Johnson vaccine), and the Chinese Sinopharm.
When India offered expedited approvals for foreign-made vaccines for emergency use in India, it had said that the vaccines that have been cleared for interim use by WHO are welcome to launch in India. Apart from WHO, it had said that vaccines cleared by US, UK, EU and Japanese regulators can also apply for rollout in India. So, it is evident that there is a level of trust that accompanies a green light for vaccines from these regulators. Remember, Covaxin has got an emergency nod from Indian health authorities, but that has not prevented controversy and uncertainty around its use.
One concern flagged by those inoculated with Covaxin is if the lack of approvals to the vaccine from international regulators will impact their travel to other countries. Speculation surrounding vaccine passports has triggered fears that countries will not accept vaccine certificates if the jab in question is not authorised by international regulators. However, those fears may be unfounded as countries like the US have so far said that only a negative COVID-19 test is enough at the time of boarding the flight out.
More importantly, the WHO nod will allow Bharat Biotech to more easily offer its shots or technology to other countries and manufacturers to boost the use of its shot globally. According to WHO, its “emergency use listing (EUL) is a prerequisite for Covax Facility vaccine supply. It also allows countries to expedite their own regulatory approval to import and administer COVID-19
vaccines”. Covax is an international alliance working to ensure equitable vaccine supply for poorer countries.
What was the approval process for Covaxin in India?
The DCGI had in January granted permission for emergency use to Covaxin based on its phase-1 and -2 clinical trials. While extending the nod, authorities had said that the “permission is given for restricted use in emergency situation in public interest as an abundant precaution, in clinical trial mode, where Covaxin… will be administered to the vaccine recipients and they will be followed up for safety.”
Vaccine trials typically include three phases of a clinical trial before they are reviewed for any approvals. Bharat Biotech had announced interim results of its Phase 3 trials in March this year and days before its meeting with WHO had shared final data from trials involving 25,800 individuals that showed an overall 77.8 percent efficacy for Covaxin. Reports said that the Phase 3 data is being reviewed by the Subject Expert Committee (SEC), an independent panel that advises DCGI on approvals for new drugs, etc.
Recently, the US drug regulator had advised that Covaxin seek full approval in that country and not an emergency nod. That was seen as a setback towards expeditiously launching the vaccine in the US, which is already seen as having a good stockpile of vaccines to meet its domestic vaccination needs.
What will happen in the meeting with WHO?
Covaxin’s 23 June date with WHO is for just a pre-submission meeting and it will see company officials share the latest data from clinical trials to the officials of the UN health body. Company officials are reported to have said that they will make a detailed presentation and will discuss the submission of the remaining sought by WHO.
The pre-submission meeting in that respect serves as a step towards the submission of the medicines dossier on the vaccine for review by WHO experts. Bharat Biotech officials had last month said they expect WHO’s EUL nod between July and September this year.
In WHO’s own words, “A pre-submission meeting is an essential component of the medicines assessment process. Pre-submission meetings provide an opportunity for advice and guidance before submission of a medicines dossier, as well as an opportunity for the applicant to meet WHO medicines assessors who will be involved in assessing their product.”
What will WHO assess as part of EUL process?
According to WHO, EUL “is a procedure for assessing unlicensed vaccines” and other interventions during public health emergencies so that such products can be quickly made available to people who need them. EUL is relevant for public health emergencies and is based on assessments of whether a “disease may cause an outbreak, epidemic or pandemic; there are no products available
capable of eradicating or preventing the disease…”
When it comes to EUL, say, for a vaccine still in the works, “WHO will assess the quality, safety and efficacy data generated during development and conduct a risk-benefit assessment to decide if they can be used outside clinical trials”. The key idea is that “for an investigational vaccine to be considered fit for use in a public health emergency, data should demonstrate that there is a benefit in the target population that outweighs the risk of its use”.
Statistically speaking, WHO has said that a COVID-19 vaccine should at least show the efficacy of 50 percent in mandated trials. Covaxin clears this requirement with its latest Phase-3 results.
But WHO points out that EUL is “only a temporary measure to ensure availability of preventive tools that present a favorable benefit-risk ratio” in a public health emergency (PHE). So, WHO says that manufacturers have to “commit to continue with the development” of the product that gets EUL and “provide detailed guidance and a risk management plan”.
How was Covaxin developed?
The vaccine has the distinction of being India’s first indigenous COVID-19 vaccine and was developed by Bharat Biotech in collaboration with the Indian Council of Medical Research (ICMR)’s National Institute of Virology (NIV). The vaccine is based on what is known as a “whole-virion inactivated vero cell” platform. Bharat Biotech has said the vaccine contains the “dead virus, incapable of infecting people but still able to instruct the immune system to mount a defensive reaction against an infection”.