Biotechnology company Bharat Biotech said on Sunday that Covaxin, its coronavirus vaccine candidate, will be at least 60% effective, reported News18. The statement was based on the trial data of the vaccine candidate.

The company said that while it aimed to achieve at least 60% efficacy, it could actually be more. “Chances of the vaccine being less than 50% effective are remote, as suggested by our trial results so far,” it said.

The World Health Organization had said that a “clear demonstration of efficacy (on a population basis) ideally with ∼50% point estimate” should be a minimum criterion for any coronavirus vaccine candidate. It had also said that the efficacy can be assessed against disease, severe disease, and/or shedding.

Malini Aisola, co-convenor of All India Drug Action Network, raised questions on the company’s claims. “Bharat Biotech says vaccine will be at least 60% effective before any results are known, she said in a tweet. “Has not shared Phase 1 & 2 results. Doesn’t come clean on adverse events. Detailed protocols for Phases 1/2 &Phase 3 r not in public domain.”

However, NITI Aayog member VK Paul, member of the Centre’s expert group on vaccines, told the news channel that the data from the earlier trials would be available after completion of phase 3 trials.

The company said on Tuesday that it had begun the third phase trials of the vaccine with 26,000 participants from across 22 sites in the country. It is conducting the trails in collaboration with the Indian Council of Medical Research.

The vaccine has so far been evaluated in 1,000 subjects in Phase I and Phase II clinical trials, the company said. Earlier this month, senior ICMR scientist Rajni Kant had expressed hope that the Bharat Biotech vaccine could be available as early as February, months earlier than expected.

Drug manufacturer Pfizer on Wednesday said that its vaccine showed 95% efficacy in phase 3 trials. Biotechnology company Moderna too had said that its vaccine candidate was found to be 94.5% effective against the virus during its phase three trials.

Meanwhile, India on Sunday registered 45,209 new coronavirus cases, taking the country’s tally to 90,95,806. The toll rose to 1,33,227 with 501 more deaths. The number of active cases stood at 4,40,962. So far, 85,21,617 people have recovered from the disease.

Race for vaccines

With so many Covid-19 vaccines in development, more results are likely to follow in the coming months. Pfizer, which has completed its trial, submitted an application on Friday for emergency use authorisation of the vaccine. Another vaccine candidate developed by the Oxford University and AstraZeneca has produced strong immune responses in older adults in second stage trials.

India has not yet signed a deal for a coronavirus vaccine so it is unclear when it will be available for use in the country, despite some leaders promising it will be available from as early as January. Availability of the vaccine in India will be subject to approval by domestic regulators, and the Indian government agreeing to purchase them. So far, many other nations including the United States, United Kingdom, the European Union, Australia and Israel have made deals to buy millions of doses of the vaccines.

Besides, the cold storage requirements also pose a challenge for developing countries like India in the procurement of the vaccines. For instance, Pfizer’s vaccine must be shipped and stored at freezing temperatures of minus 70 degrees Celsius from the moment they are bottled to the time they are ready to be injected. This is significantly lower than the standard 2-8 degrees Celsius storage requirement. Currently India has no system or infrastructure to be able to deliver a minus 80 degree Celsius vaccine.

A research by German logistics firm DHL and consultancy firm McKinsey has found that insufficient “last mile” cooling facilities in the final delivery stages and a lack of storage at clinics in large parts of Africa, Asia and South America would “pose the biggest challenge” to delivering these vaccines at scale.

The health ministry on November 18 said the government is examining all possibilities for the procurement of these vaccines despite the challenges.