Is There A Way To Prevent The Emergence Of Vaccine-Resistant Variants?

Could a combination of vaccinations and non-pharmaceutical/behavioural interventions that decrease viral transmission rates be used to decrease the risk that new problematic COVID-19 variants will emerge?

A European group has done the modelling and they published their work in the peer-reviewed journal Scientific Reports last Friday.

First, what their objective was, from the Introduction to the paper:

...(T)o our knowledge, the interplay of the population vaccination rate with the stochastic dynamics of emergence of a resistant strain has been discussed, but not formally modeled. Specifically, a concern is whether a combination of vaccination and transmission rates can create positive selection pressure on the emergence and establishment of resistant strains. To address this issue, we implemented a model to simulate the probability of emergence of a resistant strain as a function of vaccination rates and changes in the rate of virus transmission, resembling those caused by non-pharmaceutical interventions and behavioural changes...

Second, what they found, from the Abstract of the paper:

...We found that a fast rate of vaccination decreases the probability of emergence of a resistant strain. Counterintuitively, when a relaxation of non-pharmaceutical interventions happened at a time when most individuals of the population have already been vaccinated the probability of emergence of a resistant strain was greatly increased. Consequently, we show that a period of transmission reduction close to the end of the vaccination campaign can substantially reduce the probability of resistant strain establishment...

So, assuming their modelling has validity, what would be the recommendation for policy makers?

Here's what the authors had to say about that in the Discussion of the paper:

...One simple specific recommendation is to keep transmission low even when a large fraction of the population has been vaccinated by implementing acute non-pharmaceutical interventions (i.e. strict adherence to social distancing) for a reasonable period of time, to allow emergent lineages of resistant strains to go extinct through stochastic genetic drift..."

Now.

Even the best models are just that.

However, why not err on the side of caution?

_______

Of course, unlike the U.S. where the real world experiment currently being carried out is one based, to a large degree, on differences in vaccination rates, here in Canada we may soon be doing our own real world experiment that is instead based on differences in non-pharm/behavioural interventions.


.