Public health experts however find it strange that the trial was not paused. They say this is contrary to the international practice of suspending trials after an adverse event is reported. Bharat Biotech did not respond to e-mailed questions till the time of going to press. According to people familiar with the development, the volunteer concerned was hospitalised with viral pneumonitis. The subject recruitment for phase 1 study of the vaccine was initiated on July 15.
While no immediate adverse event was reported within a few hours of vaccine administration, among the 402 participants who were administered the first dose, a total of 73 adverse events were recorded. Among the 394 subjects who were administered the second dose, a total of 18 adverse events were recorded. Sources said most of the adverse effects were mild in nature and resolved. However, one serious adverse event was reported.
Addressing a webinar on Friday, Bharat Biotech chairman and managing director Krishna Ella said the company was following international guidelines and there was a reason for not disclosing adverse reactions. “There is an international clinical protocol that we need to follow very strictly. We can’t give every adverse reaction to the press. The first rule is that the ethical committee of the hospital should be informed. We have to inform the DSMB. We have to follow that and then we have to inform the DCGI. The subject expert committee reviews and the process follows. Everybody is suspicious about Indian manufacturers, but trust me we are following international guidelines.”
Experts said the discovery of a serious adverse event was a serious matter. “The purpose of phase 1 trials is to determine the safety limit of the vaccine and if you find a serious adverse event because of it, then it is a serious matter,” said Amar Jesani, editor of Indian Journal of Medical Ethics. A public health professional, who did not wish to be quoted, questioned the secrecy and wondered why the trials were not halted. “These pauses are not uncommon in largescale drug trials, and I wonder why no one ever got to know about the case,” he said.
On September 6, AstraZeneca, which is developing a Covid vaccine in collaboration with the University of Oxford, temporarily halted phase 3 trials around the globe after a trial participant reportedly developed severe adverse reactions. The company resumed clinical trials of its coronavirus vaccine candidate later after confirmation from the regulatory authorities that it was safe to do so.
At present, phase 3 clinical trials of the Bharat Biotech vaccine are underway. The company received the drug regulatory authority’s approval for the final stage of testing of its coronavirus vaccine in India late last month. Over 25,000 people have been enrolled for the trials in India and the participants will be given two doses of the experimental vaccine 28 days apart.