Mass vaccination, therefore, promotes viral evolution towards more infectious variants. The resulting enhancement of viral infectious pressure makes it more likely for everyone, including healthy, unvaccinated people to come in contact with the virus, especially in times where infection prevention measures are loosened.

To the extent that high infection rates cause people to become re-exposed shortly after a previous asymptomatic infection, their innate Sars-CoV-binding antibodies (Abs) will be suppressed by short-lived, poorly functional anti-spike Abs, known to not be responsible for preventing the infection from becoming symptomatic.

It is precisely the suppression of these broadly protective innate Abs that makes previously asymptomatically infected individuals more susceptible to disease.