During this pandemic, we’ve developed and deployed vaccines in real time. Meanwhile, sars-CoV-2 is replicating not in a dozen flasks but in tens of millions of people, some of whom have been immunized, all of whom exert selective pressure for the virus to find new, more efficient replication strategies. The virus will continue to mutate every moment of every day, for years, for decades…. For those who remain unvaccinated—the majority of humankind—there is also the horrifying prospect of a variant that is vastly more contagious or deadly.
…[Researcher Roberto Burioni] has written about the prospects for a “final” variant, a version of the coronavirus that has reached maximum transmissibility, and which becomes “the dominant strain, experiencing only occasional, minimal variations.”
The virus could accumulate mutations that allow it to circumvent immunity without suffering a major reduction in transmissibility or lethality…. Even in this scenario, Burioni told me, we’re in a fortunate position: we can quickly modify our vaccines to confront new variants. At the same time, the manufacturing and distribution challenges facing those variant-specific boosters would be colossal; we’re struggling to fully vaccinate even a quarter of the world’s population with the vaccines we already have.