E-Paper
Dropping face masks, social distancing rules may trigger new 'vaccine-resistant' Covid-19 variants: Study
The authors said that the risk of a vaccine-resistant strain of the SARS-CoV-2 emerging was the highest when a large proportion of the population was vaccinated but not large enough to achieve herd immunity.
Relaxing non-pharmaceutical interventions (NPI) such as facemasks and social distancing measures when most people have been immunised with the Covid-19 vaccine greatly increases the risk of vaccine-resistant variants of the SARS-CoV-2 virus that causes the disease, according to a new research, news agency AFP reported on Friday.
The authors of the research said that their modelling study showed the need to maintain face masks and social distancing rules until everyone is fully vaccinated against the disease. The study came at a time when nearly 60% of citizens in Europe have received at least one dose of the vaccine.
Probability of a vaccine-resistant variant
A pan-European team of experts studied the chances of a vaccine-resistant strain of the coronavirus emerging in a population of 10 million people over three years. The study was done to predict how the SARS-CoV-2 might mutate in response to vaccination campaigns.
Many variables such as vaccination, mutation and transmission rates, including recurring "waves" of infections and the fall in cases in response to lockdowns were considered for the study.
As expected, the model showed that a faster pace of vaccination would reduce the risk of the emergence of a vaccine-resistant strain.
Also read | Fourth wave of Covid-19 hits Middle East, WHO sounds alarm over delta variant
However, the authors also said that the risk of a resistant strain emerging was the highest when a large proportion of the population was vaccinated but not large enough to achieve herd immunity. They called this scenario “counter-intuitive.” The authors also said that their model estimated a threshold of 60% population being vaccinated after which, the vaccine-resistant variants appeared more likely to emerge.
Co-author of the study Simon Rella from the Institute of Science and Technology, Austria, said that the vaccines are the “best bet” to beat the Covid-19 pandemic. “What our model showed is that when most people are vaccinated, the vaccine-resistant strain has an advantage over the original strain. This means that the vaccine-resistant strain spreads through the population faster than the original strain at a time when most people are vaccinated,” Rella said in an online briefing.
The authors, based on the results of the study, urged policymakers and individuals to consider keeping the measures in place throughout the entire vaccination process.
Delta variant
Europe, which is now witnessing the rapid spread of the Delta Covid-19 variant, is currently in a similar scenario, where 60% of the population is vaccinated. In the US too, where 60% of adults are fully vaccinated, the conditions appear similar. Also, 80% of new cases of Covid-19 in the US were due to the Delta variant. The US Centers for Disease Control and Prevention (CDC) on Tuesday recommended wearing a face mask indoors for vaccinated people too, in areas where the prevalence of the Delta variant was higher.
While the Delta variant is significantly more infectious than the original variant, there is little evidence currently to suggest that it is more deadly.
(With agency inputs)
