Contracting Covid Is Like Getting an 84% Efficacy Vaccine

The discourse is ablaze with commentary about the CDC’s recommendation to temporarily halt the use of the Johnson and Johnson vaccine. The reason for the recommendation is that six women developed a rare blood-clotting disease shortly after receiving the vaccine. The recommendation does not apply to the Moderna or Pfizer vaccines, which use a different mechanism to generate immunity.

This controversy has overshadowed a more interesting development in the vaccine discourse, at least as far as my own curiosities are concerned.

Last Friday, the Lancet medical journal released a large study about the immunizing effect of having previously been infected by COVID.

The bottom line of the study is that:

A previous history of SARS-CoV-2 infection was associated with an 84% lower risk of infection, with median protective effect observed 7 months following primary infection. … This study shows that previous infection with SARS-CoV-2 induces effective immunity to future infections in most individuals.

The 84% efficacy is less than the Moderna and Pfizer vaccines, which clock in at 94% and 95% respectively. But it is more effective than the Johnson and Johnson vaccine, which has an efficacy of just 72%.

Assuming this finding holds up, this is obviously very good news for the battle against the virus. If being infected with the virus effectively immunizes you from future infection, then we should reach herd immunity more quickly than expected and immunization should ultimately find its way to almost everyone, even the vaccine resisters.