The natural immunity provided by COVID-19 infection in unvaccinated adults is on par with protection conferred from vaccines against reinfection with or hospitalization from the virus, a new study reveals. Immunity from COVID-19 was also shown to persist longer than vaccine-induced immunity.
“We found that, before the emergence of the Omicron variant, natural immunity provided a similar degree of protection against COVID-19 infection as mRNA vaccination,” summarized study author Dr. Ari Robicsek.
Dr. Robicsek is the chief medical analytics officer for the Providence health system, one of the largest health systems in the United States, which published the study in collaboration with researchers from the University of Chicago.
The study – “Rates of COVID-19 Among Unvaccinated Adults With Prior COVID-19” – found that unvaccinated adults with prior COVID-19 infection had an 85 percent lower risk of acquiring COVID-19 than unvaccinated individuals without previous infection.
“The findings that patients with prior COVID-19 had 88% protection against hospitalization for COVID-19 and 83% protection against COVID-19 not requiring hospitalization suggest that natural immunity was associated with similar protection against mild and severe disease,” explained the study.
“mRNA vaccines are associated with similar prolonged protection from severe COVID-19 as found in our study, although vaccine-associated protection from mild COVID-19 has been shown to wane at 6 months,” it continued.
Natural immunity in unvaccinated individuals was shown to persist for up to nine months following the initial infection, which was as far out as researchers were able to study. “Protection remained stable over the study period with no attenuation up to 9 months from initial infection,” it explained.
“Prior studies investigating protection against SARS-CoV-2 reinfection found similar results, with protection associated with natural immunity ranging from 80.5 percent to 100 percent,” added the paper. “This level of protection is similar to that reported for mRNA vaccines.”
The figures were based on an analysis of over 100,000 patients tested for COVID-19 at 1,300 sites of care across Providence’s massive health care system between October 1st, 2020 and November 1st, 2021. The study was published online on April 20th in JAMA Network Open.
“This data is key to helping us understand the strength and longevity of natural immunity, and allows us to compare the effectiveness of a prior infection with mRNA vaccines,” according to Dr. Amy Compton-Phillips, Providence’s chief clinical officer.
“The results provide new insight into the length of protection following an initial infection among the unvaccinated population and could have important implications for vaccination guidelines and public health policy,” she added.
The study follows an unearthed interview featuring Anthony Fauci asserting that the “best vaccination is to get infected yourself,” in reference to influenza in 2004.