Haryana Health Minister Anil Vij tweeted that he tested positive for COVID-19 on Saturday; two weeks after he participated in the Phase III trials of COVAXIN, Bharat Biotech's indigenous vaccine prepared from a COVID-19 strain isolated by the National Institute of Virology. Vij had participated in the trials on November 20 at PGI in Rohtak.
As the trials are double-blinded, it is unclear whether Vij received a dosage of the vaccine or the placebo. Bharat Biotech refused to comment on the nature of his participation but the Ministry of Health and Family Welfare statement suggested that he might have received the vaccine. In double- blinded trials, 50% of the participants receive the vaccine while the other 50% receive a placebo.
In a double-blind trial, both the participant and the health worker administering the vaccine are kept in the blind about whether a participant received the vaccine or a placebo. If the participant is aware about what he is receiving, it nullifies their participation from the trial as it raises a confounding bias in the clinical trial. It affects the study of the trial as results are pre-determined instead of being studied scientifically. Only a principal investigator is aware about the trial arm a participant belongs to.
A spokesperson from the Ministry of Health and Family Welfare commenting on Vij testing positive highlighted that the vaccine's efficacy- its action against the SARS-CoV-2 virus can only be determined 14 days after the second dose of the virus has been administered to the participant but also said that Vij has only received one dose of "the vaccine" so far. Questions about whether Vij has been unblinded to reveal whether he received the vaccine went unanswered.
The statement read, "The anti-bodies 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 (Vij) has taken only one dose of the vaccine." The spokesperson attached Vij's tweet where he shares that he tested positive along with the statement.
The pharmaceutical also released a statement clarifying the protocol for vaccine efficacy. The statement, however, does not mention the minister anywhere in its statement. " COVAXIN™ clinical trials are based on a two dose schedule, given 28 days apart. The vaccine efficacy will be determined 14 days post the second dose," read the statement.
Bharat Biotech is conducting Phase III trials for its vaccine at 25 locations in the country. More than 26,000 participants are participating in these large-scale trials to check for the safety and efficacy of COVAXIN.