COVID vaccines have proved to be magnificent successes, dramatically decreasing the number of cases, hospitalizations and deaths. If a carrier’s viral load is relatively low—meaning that fewer viral particles are shed while breathing and speaking—the risk of transmission is substantially reduced. One possible indirect benefit of a COVID vaccine, then, may be to reduce the viral load in so-called breakthrough cases, or vaccinated people who get infected. The viral load in these breakthrough cases was about three to four times lower than the viral load among infected people who were unvaccinated. And the efficacy of the COVID vaccines in protecting against illness is indeed remarkable.