Two men from the city who had participated in the phase III clinical trial of Covaxin are yet to know whether they had been administered the vaccine or given a placebo, a piece of information without which they cannot decide whether they need a Covid jab now, the men said.

One of the men, in his late 20s, had received the second dose in the second week of January. The other, in his late 30s, had received the second dose in early January.

The youths had not sought the information earlier, but now that Covid vaccination has been opened for the 18-44 age group, they need the information.

“We get calls from NICED every week. They enquire about our health. Last week, I had called the number and asked when we would get to know whether we were given the vaccine or the placebo. Now that Covid vaccination is open for people in the 18-44 age group, we need to know this. If we were given the placebo, we have to take the vaccine now,” said the younger man, a data scientist.

The National Institute of Cholera and Enteric Diseases (NICED) conducted the phase III clinical trial of Covaxin.

The other trial participant said he had got a Covid antibody test done. “I tested positive but that does not mean I was administered the vaccine. It could be that I got infected and was asymptomatic,” he said.

The younger man said his physician had told him to wait for information on the matter from the Indian Council of Medical Research (ICMR). “My doctor told me that there is no evidence or data yet to suggest what will happen if someone gets vaccinated twice,” he said.

NICED is a research organisation under ICMR.

Shanta Dutta, the director of NICED, told The Telegraph on Tuesday that they were getting in touch with the participants who were given the placebo.

“We are administering them vaccines here. They do not have to go anywhere else to get the jab,” said Dutta. “The participants can get in touch with our trial team members, whose contact numbers were given to them, to know whether they were given the vaccine or the placebo.”

The two participants said they had called the numbers but did not get any clear response.

Covaxin — one of the two Covid vaccines being administered in India, the other being Covishield — has been developed jointly by ICMR and Bharat Biotech, a private company in Hyderabad.

In the phase III trial, which determined the efficacy of the vaccine, the participants were given two doses, similar to the actual vaccination process.

While some were administered the vaccine, others were given the placebo, a solution without the contents of the vaccine.

The placebo is administered to participants in a vaccine trial to understand whether those who were given the vaccine mounted a better immune response than the others.

“It was a unique situation. The vaccine was given emergency use approval before all trial reports were published. This had to be done because of the exceptional situation,” said Dipyaman Ganguly, an immunologist at the Indian Institute of Chemical Biology in Jadavpur.

“I believe that the participants of the clinical trial deserve to know whether they were administered the vaccine or the placebo, because that will determine their decision to take a vaccine against Covid. I am sure ICMR will inform the recipients of the placebo sooner or later,” said Ganguly.

Case count

Bengal on Tuesday recorded 17,639 new infections, 107 deaths and 16,547 recoveries. The number of active cases has risen to over 1.2 lakh. Of the 107 deaths, 31 were reported from Calcutta and 33 from North 24-Parganas. While Calcutta recorded 3,914 new infections, North 24-Parganas reported 3,954.