In an about-face in favor of persons who had COVID and now have natural antibodies, Spectrum Health, Michigan, said it would lift vaccine mandates for anyone who can prove they have natural immunity to COVID-19.
All individuals with a positive PCR or antigen test for COVID-19 plus a positive antibody test from within the past three months can qualify for the exemption. Spectrum also allows medical and religious exemptions. The policy could change if future evidence shows natural protection is either waning or longer-lasting, depending on the circumstances, Spectrum said.
In reference, two different studies on natural immunity had different outcomes. Cleveland Clinic, which isn't making vaccination mandatory for its employees, studied 50,000 of its employees and found that none who had been previously infected were reinfected.
On the other hand, the CDC did a study in Kentucky of those with previous infections but were unvaccinated as per CDC's definition versus those who had both natural infection and were vaccinated and found that those who had natural infection but were not fully vaccinated were 2.34 times as likely to get reinfected than those who had both the infection and the shots.
The CDC had just 246 fully vaccinated patients in the case study and nearly twice as many unvaccinated — 492 — in the control "unvaccinated" group to come up with that number. The CDC's definition of "fully" vaccinated only applies to individuals who have received the full recommended doses of vaccine, and then only if 14 days or more have passed since receipt of the last dose.
The Detroit News September 12, 2021
Hospital Review August 9, 2021
CDC August 13, 2021