Awareness drives on vaccines must to fight off scepticism, importance of masking, distancing underscored by the episode
Vij participated in a double-blind trial—neither he nor the person administering the shot knew whether the shot contained the vaccine or a placebo.
The controversy over Haryana minister Anil Vij testing positive for Covid-19 days after participating in the clinical trials for Bharat Biotech’s Covaxin underscores the need for the government and civil society to create basic vaccine-awareness among the masses. This will not only help battle vaccine scepticism but also prevent risky behaviour by trial participants/vaccine recipients. Vij testing positive was breathlessly covered by the media—his volunteering for the trial had been covered extensively too—without accompanying explainers on how he could have contracted the virus. The rather simplistic narrative of vaccine failure in the immediate aftermath makes for a dangerous cocktail along with ‘pandemic fatigue’ and confusion over some other vaccine-trials (the Oxford vaccine results announcement/unintended ‘mis-dosing’). It is corrosive for public trust in the robustness of vaccine-science.
Vij participated in a double-blind trial—neither he nor the person administering the shot knew whether the shot contained the vaccine or a placebo. If Vij received the placebo, then he would not have had any protection against the virus to begin with. However, if he received the vaccine, his subsequently contracting Covid-19 needs to be seen against factors such as the trial-dose-regimen and vaccine efficacy. Covaxin is a two-dose vaccine, with the second dose administered 28 days after the first, and Bharat Biotech says that the antibody build-up for an effective response against SARS-CoV-2 occurs only after two weeks from the second dose. So, even if Vij received the vaccine in the first shot, there is always a chance that he could have been susceptible to Covid-19—given he received the shot on November 20, he is still in the interval between the two doses. That said, he, or any other trial participant—or eventually, vaccine-recipient—could still suffer from Covid-19 after receiving the complete dose of a vaccine. How many vaccine recipients still risk the disease will depend on the vaccine efficacy, which will only be clear at a later stage in a trial. For determining this, a threshold number of participants in a trial will have to contract the disease, and based on a comparison of the relative risk of participants in the vaccinated and the placebo arms, the vaccine efficacy will be determined.
Given India has set a 50% efficacy threshold—as recommended by the World Health Organization—for any vaccine that is to be authorised for public use, there will always be some within the vaccinated population who will still contract the disease. This shouldn’t mean that a vaccine or the entire gamut of vaccines rolled out are dismissed as ineffective in the fight against Covid-19. To counter such a perception—vaccine scepticism in the context of Covid-19 is a significant threat, some studies have determined—scientific concepts must be explained in a digestible manner, and the government and the civil society have to see this as integral to the rolling out of Covid-19 vaccines. The narrative can’t be left on auto-pilot. That said, the Vij episode has important lessons for the masses too. It underscores the importance of distancing and proper use of masks, even by people who have received vaccines; bear in mind, a systemic vaccine can train your immune system to fight off the virus once it enters the body, but it won’t block the virus’s entry (though there are specific nasally-administered vaccine candidates that have claimed to provide topical protection).