A vaccine for COVID-19 from India is unlikely to be ready for public use by August 15 but early data on whether it is safe and proof of its working could be available by then, say clinicians involved with the trial.
On July 2, Director General of the Indian Council of Medical Research (ICMR) Dr. Balram Bhargava sent out a letter asking officials at 12 hospitals across the country to expedite the vaccine testing process.
The vaccine candidate, called Covaxin, has been developed by Hyderabad-based, Bharat Biotech India Ltd (BBIL) who got approvals from the Drug Controller General of India on June 29 for phase-1 and phase-2 trials.
The trials are done on groups of people and meant to test if the vaccine is safe in humans and produces protective antibodies. The potential vaccine in question is a sars-cov-2 strain sourced from the ICMR-National Institute of Virology. The aim is to test if the weakened form of the virus can stimulate enough immunity to protect healthy people from Sars cov-2 infection.
However a paragraph in Dr. Bhargava’s letter suggested a haste and presumption of the vaccine’s protective abilities. “It is envisaged to launch the vaccine for public health use latest by15th August, 2020 after completion of all clinical trials. BBIL is working expeditiously to meet the target, however final outcome will depend on the cooperation of all clinical trial sites involved in this project.”
Though the letter wasn’t officially released by the ICMR, the body confirmed its veracity.
A scientist familiar with India’s COVID-19 vaccine development strategy, but who couldn’t be identified, said the vaccine had potential but it was “overtly optimistic” to expect it soon. “This vaccine has much potential but is at early stages. To promise delivery on a month’s timeline is overtly optimist. In exhorting partners for preparedness, due process and trial-site preparedness is also necessary.”
Two doctors who are leading trials at different locations told The Hindu they were awaiting clearances from their institutional ethics committees—a mandatory requirement—to begin recruiting volunteers. Only after such clearance could they proceed with tests. Both said that given how the trial was designed, it would be possible to assess the vaccine’s suitability or inadequacy for dissemination in the wider population.
“We haven’t yet begun recruitment but are in the process of awaiting institutional ethics clearance,” said Dr. R. Vasudev, King George Hospital, Vishakapatnam, and among the 12 sites, “We need 100-150 recruits per centre and by August 15, we should be able to get a sense of the safety, immunogenicity and possible efficacy. After four days, we are likely to get approval and begin recruitment.”
Another doctor said that each trial site posed its own unique challenges in sourcing patients and, therefore, it was possible for one centre to finish phase-1 and phase-2 studies but for others to lag. This was a common cause of delay in human trials. “Were everything to go like clockwork, it’s possible to confidently determine vaccine safety by August 15”, said Dr. Venkata Rao, Principal Investigator and based at the Institute of Medical Sciences and SUM Hospital, Jajpur, Odisha, “However, until now, we weren't made aware of a specific timeline, that it was to be ready by August 15.”
The primary aim of the phase-1 trial was to check if there were side-effects or any adverse reactions. In phase-2, it would be to check if on administering the vaccine a measurable quantity of protective antibodies are produced by the immune system. Details of the study plan are available on the ICMR’s Clinical Trial Registry and this describes how 1,125 volunteers will be recruited pan-India, divided into appropriate groups with some getting the actual vaccine 14 days apart and others a placebo. Those tested are expected to be followed up at different stages: 7 days, 28 days, 104 and 196 days. It isn’t clear if phase-3 will follow this or depending on phase-2, be co-terminus.
Krishna Ella, president, Bharat Biotech, has himself reportedly said a vaccine would be available in market only by next year.
“Unlike in a drug trial, where phase-3 compares a new drug to another that is the standard of care, in a vaccine trial, phase-3 is similar to phase-2. Except that it’s done on field conditions and in much larger population and tested for safety and immunogenicity [producing antibodies],” said Dr. Rao, “So good phase-2 data should, in most cases, translate to good phase-3 data.”
None of the doctors said they were immediately aware of pre-clinical data or how the the vaccine performed on lab animals.