Hyderabad-based Bharat Biotech, which is developing the indigenous COVID-19 vaccine Covaxin, on Saturday issued a statement after Haryana Health Minister Anil Vij, who had taken part in the phase-3 clinical trials, tested positive for coronavirus. After questions were raised over the efficacy of the vaccine candidate, Bharath Biotech said that for the vaccine to work, it needs to be taken in two doses, and the vaccine’s efficacy can only be known two weeks after the second dose, which is administered 28 days after the first dose.
Bharat Biotech also stated that it is carrying out a double-blind study, which means neither the participants nor the administrators are aware whether the individual is receiving the actual vaccine or a placebo. A placebo is a shot that looks identical to the treatment administered in a clinical trial, but isn't.
Anil Vij, the Haryana Health Minister, had taken part in the vaccine trial on November 20, as part of phase 3 clinical trials. He was administered a dose, but as per protocol, Bharat Biotech has not specified whether the minister received the vaccine dose or the placebo.
Bharath Biotech has stated that Covaxin volunteers only have a 50% chance of receiving either the vaccine or a placebo in the phase 3 trials. The company added that Covaxin is designed to be protective two weeks after the volunteers receive the second dose. The pharma company has added that as per the norm, they have advised all their volunteers to continue following prevention guidelines for COVID-19 set by the Union Ministry of Health and Family Welfare.
The company released the statement after Anil Vij tested positive for the coronavirus on December 5, days after taking part in the trial, causing a tweetstorm with many questioning the vaccine’s efficacy. However, as it's a double-blind study, there is no way for the minister to know if he had taken a vaccine shot or a placebo.
Stressing that experts would know better about how the COVID-19 vaccine works, Vij told PTI over the 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."
After media reports of Vij testing positive, the Health Ministry issued a statement to the media: "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. Since this is a two-dose vaccine. Minister in question has taken only one dose of the vaccine."
Bharath Biotech had begun the phase 3 clinical trials on November 16, and at the time, the company’s chairman and managing director, Krishna Ella, had said that the firm was attempting to make the vaccine in the form of a single-dose nasal spray. The CEO had raised concerns over the prospect of distributing a two-drop injectable vaccine that requires cold storage to 1.3 billion people. The company observed that over 2.6 billion doses will have to be developed if the vaccine is in its 2-dose form.