(p. A17) Public-health officials ruined many lives by insisting that workers with natural immunity to Covid-19 be fired if they weren’t fully vaccinated. But after two years of accruing data, the superiority of natural immunity over vaccinated immunity is clear. By firing staff with natural immunity, employers got rid of those least likely to infect others. It’s time to reinstate those employees with an apology.
For most of last year, many of us called for the Centers for Disease Control and Prevention to release its data on reinfection rates, but the agency refused. Finally last week, the CDC released data from New York and California, which demonstrated natural immunity was 2.8 times as effective in preventing hospitalization and 3.3 to 4.7 times as effective in preventing Covid infection compared with vaccination.
Yet the CDC spun the report to fit its narrative, bannering the conclusion “vaccination remains the safest strategy.” It based this conclusion on the finding that hybrid immunity—the combination of prior infection and vaccination—was associated with a slightly lower risk of testing positive for Covid. But those with hybrid immunity had a similar low rate of hospitalization (3 per 10,000) to those with natural immunity alone. In other words, vaccinating people who had already had Covid didn’t significantly reduce the risk of hospitalization.
Similarly, the National Institutes of Health repeatedly has dismissed natural immunity by arguing that its duration is unknown—then failing to conduct studies to answer the question. Because of the NIH’s inaction, my Johns Hopkins colleagues and I conducted the study. We found that among 295 unvaccinated people who previously had Covid, antibodies were present in 99% of them up to nearly two years after infection. We also found that natural immunity developed from prior variants reduced the risk of infection with the Omicron variant. Meanwhile, the effectiveness of the two-dose Moderna vaccine against infection (not severe disease) declines to 61% against Delta and 16% against Omicron at six months, according to a recent Kaiser Southern California study. In general, Pfizer’s Covid vaccines have been less effective than Moderna’s.
The CDC study and ours confirm what more than 100 other studies on natural immunity have found: The immune system works. The largest of these studies, from Israel, found that natural immunity was 27 times as effective as vaccinated immunity in preventing symptomatic illness.
None of this should surprise us. For years, studies have shown that infection with the other coronaviruses that cause severe illness, SARS and MERS, confers lasting immunity.
For the full commentary, see:
(Note: the online version of the commentary has the date January 26, 2022, and has the title “The High Cost of Disparaging Natural Immunity to Covid.”)
The Israeli preprint study mentioned above is:
Gazit, Sivan, Roei Shlezinger, Galit Perez, Roni Lotan, Asaf Peretz, Amir Ben-Tov, Dani Cohen, Khitam Muhsen, Gabriel Chodick, and Tal Patalon. “Comparing Sars-Cov-2 Natural Immunity to Vaccine-Induced Immunity: Reinfections Versus Breakthrough Infections.” medRxiv (2021): doi: https://doi.org/10.1101/2021.08.24.21262415.