Image courtesy: Business Standard
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Inadvertently, a recent study in the United Kingdom on vaccination effectiveness against variations of the Covid-19 virus has uncovered a key gap in India’s own immunisation efforts: the absence of proof of how successful these doses are on the country’s own population.
Experts predict that the lack of such data will make it difficult to develop evidence-based plans and adapt appropriately when fresh data from real-world research comes elsewhere. Take, for example, PHE data indicating that two doses of the Covid-19 vaccine are required to provide “strong protection” against the B.1.1.7 and B.1.617.2 strains.
Because of its tiny sample size, PHE’s study looked at all symptomatic Covid-19 cases, but it doesn’t determine whether these vaccines protect against severe sickness and mortality, which is India’s major goal. Second, the study considers a 12-week interval between the first and second doses of the AstraZeneca vaccine, whereas patients in India have received their second doses at 4-6 weeks.
Dr Gagandeep Kang, a vaccination expert and professor at Christian Medical College in Vellore, said, “I’m not sure what these findings signify for India because I don’t have any Indian data to go on.” “In the UK, only a small percentage of those who had previously been infected were given the vaccine, whereas in India, sero surveys conducted before the second wave revealed that 50% of the population in urban areas and a smaller amount
According to her, these findings highlight India’s need to undertake its own vaccination effectiveness study “immediately.” “I’d love to see real-world vaccine performance in India, complete with comprehensive sequencing, since this is an opportunity for Indian research to influence the rest of the world, not the other way around,” she said.
When simply looking at moderate to severe illnesses and mortality benefits, the effectiveness of these vaccines is likely to be different. “Having our own statistics on that would be quite beneficial,” said Dr. Chandrakant Lahariya, a vaccine expert who specialises in public policy and health systems.
Experts claim that, unlike the United Kingdom, which has been collecting data from those who have received vaccines from Pfizer and AstraZeneca, India has not taken use of its potential to examine those who have received vaccines here.
Instead, it has relied on data from places like the United Kingdom to better understand the performance and dosing intervals of vaccines like Covishield, AstraZeneca’s Indian version. According to the government’s Covid-19 vaccination registration system CoWIN, Covishield has accounted for over 90% of the doses delivered thus far.
According to the Health Ministry, almost 43 million people in the country have gotten two doses of either Covishield or Covaxin in the last four months. Experts believe it has yet to make public any real-world data, such as whether giving Covishield at a 4-6 week and a 6-8 week interval gave adequate protection.
Vaccine effectiveness studies are simple to plan and carry out, according to Dr. Lahariya. According to him, specific sub-groups such as healthcare professionals, army and police officials, and railway employees have been vaccinated “to a large extent.”
“These population sub-groups can provide useful insight into the country’s real-world vaccine effectiveness,” he said. “However, while these groups exist, I’m not aware of any official study or analysis being conducted to evaluate issues like breakthrough infections following immunizations or even a comparison between individuals who have been vaccinated and those who have not been vaccinated,” he added.