“If the virus changes substantially, particularly the spike proteins, then it might escape a vaccine. We want to slow transmission globally to slow the clock,”
Is this why some are saying we might need a booster shot in a few years?
Is this why some are saying we might need a booster shot in a few years?
There is little selection pressure on the virus for the spike proteins to evolve and change. SARS-CoV-2 infects human cells just fine using its current spike protein. [1]
We’ll have to watch for signs of selection pressure as more and more of us get vaccinated to recognize the spike protein. Hopefully SARS-CoV2 mutates too slowly to escape the vaccines, or can only escape with sharply reduced infectivity and virulence.
> Studies of common-cold coronaviruses, sampled across multiple seasons, have identified some signs of evolution in response to immunity. But the pace of change is slow, says Volker Thiel, an RNA virologist at the Institute of Virology and Immunology in Bern. “These strains remain constant, more or less.”
So there seems to be a pretty good chance that this won’t really be an issue.
Anyhow, if the spike proteins vary too much, then we'll need a new vaccine all together, not just a booster for the current one
If COVID begins to mutate in ways that make the vaccine (and anti-bodies it causes) less effective, we would be in a situation like the flu - annual vaccines based on that year's strain (which takes some guesswork). The disease is then called endemic.
But, there is currently no indication COVID will become endemic. It might. It might not. We don't know, but current knowledge tends to indicate it won't.