You should not think about it: a corona variant that our vaccines do nothing against. How do we prevent such a mutant from developing?

As far as the corona pandemic is concerned, we have entered calmer waters. The number of new infections per day is past its peak and most measures have been relaxed. But, what if a new variant emerges that does not care about the vaccines? Then we could just be back to square one.

What’s the best way to avoid that disaster scenario? A team of Israeli, German and American scientists tackled that question. Their conclusion, published in Nature Human Behavior: vaccinating everyone as soon as possible while keeping their distance, offers the smallest chance of a variant that is resistant to the vaccine.


The team relied on data from Israel, the United States, United Kingdom, Brazil, France and Germany. They put that data into a mathematical model that took into account the number of people who were vaccinated and the degree of social distancing, which adapted to the number of infections. They then looked at the chance that a variant would emerge that cared much less or not at all about the vaccines.

To keep their calculations manageable, the researchers simplified a number of things. For example, they assumed that the original and the new corona variants are exactly as lethal, that all vaccines consist of a single dose, and that a vaccine protects against a new variant just as well as a previous infection.

The influence of seasons on the virus and the fact that the protection offered by a vaccine slowly decreases were also not included in the initial calculations. Some of these simplifications were already examined by the researchers themselves by extending their model. Others will have to tackle future studies.

The conclusion of the current study, the researchers write, is that “if you vaccinate slowly, vaccine resistance is likely, even if people keep their distance.” If you vaccinate quickly and in the meantime continue to practice social distancing, “the emergence of mutants can be prevented”.

Worst case scenario

Marjolein van Egmond, professor of immunology at Amsterdam UMC, agrees with the researchers’ final conclusion. She does wonder how much practical value it has. “It just takes time to make and roll out a vaccine. Even with the record pace at which the corona vaccines have been developed, it took a year and a half before most of the Netherlands was vaccinated.”

Furthermore, Van Egmond notes that many mutants arose before large-scale vaccination was carried out. “Even early forms of omikron, which do best evading our immune system after vaccination or infection, probably emerged early in the pandemic.”

She also says that vaccine-resistant variants are no longer seen as the most likely scenario, but more as a worst-case scenario. “We are already several variants further and the vaccines still protect well against serious disease. Although that can of course still change; we cannot see into the future.”

western perspective

Van Egmond’s main objection is that the study is very much written from a Western perspective. “A new, resistant variant could theoretically arise anywhere, but the chance is greatest in individuals with compromised immune systems – for example, people with HIV in Africa. And there, vaccination campaigns are more difficult to organize, while social distancing means a loss of income needed to survive.”

The fact that a large part of the world has not yet been vaccinated is also a thorn in the side of the researchers themselves. Our results highlight the importance of a global effort to rapidly vaccinate as many individuals as possible, especially in densely populated countries with limited access to vaccines.