In "Herd Immunity Is Over—Long Live Superimmunity" (op-ed, Jan. 18), Allysia Finley presents an excellent discussion of the possibility that "people who have been vaccinated or previously infected will develop superimmunity," and that the SARS-CoV-2 virus will become "annoying but rarely deadly or disruptive."
There are, however, several important caveats to those speculations. First, the price we are already paying for the possible progression of Covid-19 to endemic, rather than pandemic, is horrific. Hospitalizations are still running high.
Second, we don't yet know what percentage of those infected with Omicron will progress to post-Covid-19 syndrome, in which signs or symptoms persist for more than four weeks after the diagnosis of infection. If the incidence is anywhere near the 10% to 30% following Alpha or Delta infections, our healthcare system will be stressed to the breaking point.
Finally, every Covid infection results in viral replication, the creation of new mutants and the opportunity for Darwinian evolution to test them for "fitness"—greater transmissibility and ability to evade immunity. These all augur in favor of aggressive actions to flatten the curve of infections.
Henry I. Miller, M.D.
Redwood City, Calif.
Dr. Miller, a co-discoverer of a critical enzyme in influenza virus, was founding director of the FDA's Office of Biotechnology.