Safety check

As trials of vaccine candidates are expedited, worries abound about the consequences of haste

- NAMITA KOHLI

ON SEPTEMBER 26, a group of public health experts wrote an open letter to Dr Albert Bourla, CEO of US pharma giant Pfizer, which is developing a Covid-19 vaccine candidate with German firm BioNTech. The company’s mRNA vaccine is one of the world’s leading candidates, and Bourla’s claims of a “clinical answer” to its phase 3 trials by October end has triggered safety concerns among a section of global experts. In the letter, they urge the company to wait until the end of November before seeking emergency authorisation for the vaccine to ensure that rigorous safety standards are followed and public trust and confidence in the vaccine is guaranteed.

According to the WHO, 40 vaccine candidates are being clinically evaluated, of which 10 have entered phase 3 trials, which involve testing the vaccine on thousands of people. In that context, the next couple of months will be crucial for regulators, vaccine manufacturers and distributors across the world, and put the world’s best delivery systems to test. With emerging possibilities of emergency use authorisation (EUA) for multiple candidates, safety and immunogenicity data is also being closely evaluated.

Union Health Minister Dr Harsh Vardhan has said that India is considering EUA, too. An EUA allows the vaccine to be used before it is fully licenced, after conducting a risk-benefit analysis based on available data. Normally, the third trial [phase 3] takes about six to nine months. But if the government decides, this period can be cut short through an EUA, Vardhan said. “Any emergency authorisation is always done by adopting reinforced safeguards so that people do not worry about safety,” he said. “A high-level group has been formed to monitor the pace of the vaccine development under the direct guidance of Prime Minister Narendra Modi. There will be no shortcut on safety. EUA will be given only if it meets the standards.”