After the vaccine has been used, the mask cannot be removed. During the vaccination period, the spread of the virus must be curbed to prevent the emergence of drug-resistant variants.

A model study recently published by Natural Science Research’s "Science Report" shows that during the period of large-scale vaccination, non-drug means, such as wearing a mask, are still needed to reduce the spread of the new coronavirus in order to reduce resistance to the vaccine.
Probability of the emergence of the virus strain
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The research was participated by scientists from many countries in Europe
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The Austrian Institute of Science and Technology scientist Fjordor Kandraszow and his colleagues simulated the possibility of drug-resistant strains appearing within 3 years among 10 million people in the first year of vaccination

The research team’s model shows that rapid vaccination reduces the possibility of drug-resistant strains
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But the model also shows that if the intervention of non-drug means is relaxed when the majority of the population has been vaccinated, the possibility of drug-resistant strains will greatly increase

The study also found that when more than half of the population has been vaccinated but has not yet reached herd immunity, the risk is highest at this stage
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This phenomenon is called "selection pressure": as more and more people produce antibodies, the competitive advantage of more resistant strains increases, and the risk of more vaccine resistant variants increases.

And Europe is at this "high-risk" moment
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At present, more than 60% of the EU population has received at least one dose of vaccine, but it is far from achieving herd immunity

Researchers suggest that before reaching herd immunity, we should continue to strictly implement epidemic prevention measures such as wearing masks, extensive testing, and maintaining social distance to reduce the rate of virus transmission
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They believe that any means to curb the spread of the virus, such as increasing the number and scope of tests, strictly tracing contacts, high sequencing rates, and travel restrictions, can increase the probability of extinction of new strains

However, this study also pointed out that in their investigation, there was no modeling analysis of the impact of these individual measures on the spread of the virus
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The author of the paper therefore concluded that as some countries postpone vaccination, it is more likely that vaccine-resistant strains will appear around the world.