The two-dose COVID vaccines are far better at preventing a COVID infection than "natural immunity," new research says.
The study, published Friday by the Centers for Disease Control and Prevention (CDC), looked at two groups: Unvaccinated individuals who had previously gotten COVID, and fully vaccinated individuals who had never been infected with COVID.
The study found the group with "natural immunity" was 5.49 times as likely to test positive for COVID than the fully vaccinated group.
"The data demonstrate that vaccination can provide a higher, more robust, and more consistent level of immunity to protect people from hospitalization for COVID-19 than infection alone for at least 6 months," the CDC said in a news release.
The agency's director, Dr. Rochelle P. Walensky, said the study "adds more to the body of knowledge demonstrating the protection of vaccines against severe disease from COVID-19."
Natural immunity is an oft-cited talking point among anti-vax groups and the vaccine skeptic crowd. That include Minnesota gubernatorial candidate Scott Jensen, who has asked why natural immunity is being "ignored" despite being "far more effective" than vaccines — a claim that was already unproven before the release of this most recent study.
While natural immunity does offer infected individuals at least some level of protection, it's unclear just how effective it is and how long that protection lasts. (It's also worth noting natural immunity requires someone actually get COVID, which carries risks of death, hospitalization and long-term symptoms).
The study published Friday looked at hospitalized adult patients across nine states, including Minnesota, from January through September of 2021. The previously infected individuals (1,020 total) included in the study all had COVID sometime between 90 and 179 days prior to being hospitalized for COVID-like symptoms. About 9% of them against tested positive for COVID while hospitalized.
The vaccinated group (totaling 6,328 people) had all been fully vaccinated via an mRNA vaccine (so not Johnson & Johnson) 90-179 days before their hospitalization, and had no previous documented COVID infection. About 5% tested positive for COVID while hospitalized.
Dr. Charlene McEvoy, MD, of HealthPartners Institute, and Dr. Anupam B. Kharbanda, MD, with Children's Minnesota, are listed among the study's authors.