Covaxin is a two-dose anti-coronavirus vaccine and Haryana health minister Anil Vij, who had volunteered for its phase-three trial, was given only the first dose, the Union health ministry clarified on Saturday hours after the minister announced that he has tested positive for COVID-19.
Vij had offered to be the first volunteer in the phase three trials for Covaxin, an indigenous potential vaccine against COVID-19 being developed by Bharat Biotech in collaboration with the Indian Council of Medical Research.
On Saturday, the Union health ministry said, "The antibodies against the infection build up in a human being only after a specific number of days pass after the second dose of the vaccine is taken. This is a two-dose vaccine. The minister in question has taken only one dose of the vaccine."
The Haryana health minister too said antibodies start to develop after administration of the second dose, which is given 28 days after the first shot, and there is no protection during this period. The 67-year-old minister was given the first shot on November 20.
Stressing that experts would know better about how the COVID-19 vaccine works, Vij told PTI over phone: "I was told that antibodies start to develop after the second dose, which is administered after 28 days of getting the first shot. And full antibodies are developed 14 days after the second dose is given. So, the complete cycle takes 42 days. In between there is no protection."
Asked about his condition, Vij said he has sore throat, fever and body ache.
"But overall I am okay," he said.
The minister said that he had gone to Panipat a few days ago where he spent two to three hours with a BJP leader, who too has tested positive for COVID-19.
In a statement, Bharat Biotech defended its COVID-19 vaccine, Covaxin, terming it safe and efficacious.
The drug firm said its vaccine Covaxin is based on two dose schedule and its efficacy is determined 14 days post the second dosage.
"COVAXIN clinical trials are based on a 2-dose schedule, given 28 days apart. The vaccine efficacy will be determined 14 days post the second dose," Bharat Biotech said in a statement.
Bharat Biotech said the phase 3 trials of the vaccine are double blinded and randomised, where 50 per cent of subjects will receive the vaccine and 50 per cent of subjects will receive placebo.
Covaxin is a fully indigenously developed COVID-19 vaccine, with the largest Phase 3 clinical trial conducted in India, on 26,000 subjects across 25 sites, it said.
The goal is to evaluate the efficacy of COVAXIN across the country, the company added.
The phase 3 trials of the vaccine is the only efficacy trial being conducted in India for COVID-19 vaccines, to determine its suitability to the diverse Indian population, Bharat Biotec said.