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‘No need to worry, but we have to prepare’ | India News

An Israeli study sounded the alarm when it suggested that those vaccinated could be eight times more susceptible to the South African variant of Covid-19 than the unvaccinated. Lead virologist Dr. Gagandeep Kang, during an interaction with TOI, explains why the implications are not as severe as they appear.
Are the results of the Israeli study as bad as they sound? If not, why not?
The study took people who became infected after vaccination (either full immunization with two doses or partially immunized, from the moment the first dose is expected to be activated until the second dose begins, that is, from two weeks after from the first dose up to a week after the second dose) and compared them with unvaccinated infected people. Most infections were due to B.1.1.7 (UK variant) and there was some reduction in effectiveness in those partially immunized, but there was a small number with B1.351 (South African variant), with eight cases in fully vaccinated individuals and one in unvaccinated. This sounds concerning and it appears that the vaccine is not working against B1.351. But there were no cases of B1.351 more than 14 days after the second dose.
What does this mean? It is possible that while the design of this study showed reduced early effectiveness against B1.351, the effect of the vaccine is showing up later, long enough to stop later infections. We will need other studies to confirm if this is really the case.
Although this study is specifically about the Pfizer vaccine, would it have any implications for other vaccines?
All spike protein-based vaccines can have similar problems and we need to do exactly the kind of vaccine effectiveness studies that are being rolled out around the world. WHO has guidance on how these studies should be conducted, even in poorer settings without the types of surveillance systems available in richer countries.
Given that we are not using the Pfizer vaccine and the South African variant is not very common in India, is there any cause for concern in India?
The concern is the variants and how the vaccines will work. This study is about the Pfizer vaccine, but studies using other vaccines in other settings will also give us an early warning on what to expect with the variants. I don’t think we should worry, but we must prepare. Without the ability to measure the extent of the problem before and after any intervention, we will apply control measures without understanding their impact. That’s not science, it’s shooting in the dark.
Considering that we have identified variants in India, and much of the current increase is attributed to variants, what does that imply for our vaccination strategy?
Based on limited sequencing data from India, we know we have the UK variant in Punjab. In the UK, there was an almost vertical rise in cases with this variant, which is more communicable and causes more serious disease. As far as we know, we have far fewer of the so-called South African and Brazilian variants, and they may not be spreading as widely. The ‘double mutant’ or B1.617 has been found in a good proportion of cases, but we have not yet put the pieces together to determine how much this variant contributes to disease and what the biology of the virus predicts for vaccine performance. We need to establish the ability to study diseases and disseminate them on a finer scale in the community and much deeper in the laboratory and then synthesize the data to predict what this might mean for our vaccination strategy. As far as I know, we don’t have the comprehensive, integrated research approach that is really needed, operating at the speed and scale that is needed.

Times of India

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