“The contents of the actual Covid-19 vaccine will be the same as that of the placebo, the only difference being the latter will not have antigens,” said Dr Dhananjay Lad, director of Crom Clinical Research, the agency selected to conduct the trials in Goa.
He said some candidates may be given placebos as per protocol drawn by the Indian Council of Medical Research (ICMR). All candidates of the trials are given a fair idea about it without disclosing who will be in the placebo group and who will get the vaccine.
Lad, however, said that he is not authorised to speak about the content of the vaccine or the sample size of the placebo group. “A controlled group is required to check the safety and efficacy of the new vaccine,” he said.
“Whenever comparative parameters are not available for a new drug, placebos have to be introduced,” he said.
He added that since there is no marketed Covid-19 vaccine available anywhere in the world, it is not possible to compare it with similar vaccines.
He said that after getting the jab, participants are under observation for half an hour, since most of the content of the vaccine is absorbed in the body in the first 30 minutes.
“There is no question of pain in the test arm either with placebo or vaccine,” he said. “So it shouldn’t be construed by any candidate that if he/she doesn’t get pain after the shot, it is a placebo.” He was referring to several queries from participants who did not experience any reaction after vaccination.
The trials are underway at Redkar hospital in North Goa, and more than 600 candidates in Goa have so far registered to participate in the trials.
Lad said they are only taking 40 appointments a day. Persons above 18 can participate by submitting their identity proof, after which persons will be called for trials.
“We have participants from all sections, including healthcare workers,” he said.