From a WSJ article Omicron Makes Biden’s Vaccine Mandates Obsolete by Luc Montagnier and Jed Rubenfeld.
The little data we have suggest the opposite. One preprint study found that after 30 days the Moderna and Pfizer vaccines no longer had any statistically significant positive effect against Omicron infection, and after 90 days, their effect went negative—i.e., vaccinated people were more susceptible to Omicron infection. Confirming this negative efficacy finding, data from Denmark and the Canadian province of Ontario indicate that vaccinated people have higher rates of Omicron infection than unvaccinated people.
According to the CDC, the overwhelming majority of symptomatic U.S. Omicron cases have been mild. The best policy might be to let Omicron run its course while protecting the most vulnerable, naturally immunizing the vast majority against Covid through infection by a relatively benign strain. As Sir Andrew Pollard, head of the U.K.’s Committee on Vaccination and Immunisation, said in a recent interview, “We can’t vaccinate the planet every four or six months. It’s not sustainable or affordable.”
In any event, the vaccine mandates before the court don’t require boosters. They define “fully vaccinated” as two doses of Moderna or Pfizer-BioNTech or one dose of Johnson & Johnson. Even if boosters would help, the mandates would leave tens or hundreds of thousands of unboosted employees on the job, who have zero or negative protection against Omicron infection, and who would be highly contagious if they become infected. In other words, there is no scientific basis for believing these mandates will curb the spread of the disease.