(HealthDay News) – The odds of COVID-19 hospitalization are increased more than fivefold for unvaccinated patients with a previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection than among individuals who are fully vaccinated with an mRNA COVID-19 vaccine, according to research published in the Oct. 29 early-release issue of the U.S. Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report.
Catherine H. Bozio, Ph.D., from the CDC COVID-19 Response Team, and colleagues examined hospitalizations in adults with COVID-19-like illness using data from the VISION Network for 187 hospitals across nine states and compared the odds of receiving a positive SARS-CoV-2 test result for unvaccinated patients with a previous SARS-CoV-2 infection occurring 90 to 179 days before hospitalization and patients who were fully vaccinated with an mRNA COVID-19 vaccine 90 to 179 days before hospitalization.
The researchers found that after adjustment for sociodemographic and health characteristics, the odds of laboratory-confirmed COVID-19 among COVID-19-like illness hospitalizations were higher among unvaccinated, previously infected individuals than among fully vaccinated recipients of an mRNA COVID-19 vaccine (adjusted odds ratio, 5.49).
“[These data provide] powerful evidence that vaccinations offer superior protection against COVID-19 than relying on natural immunity alone,” a coauthor said in a statement. “Many have been asking if they should get vaccinated if they’ve already been infected — this research shows the answer is yes.”
Several authors disclosed financial ties to pharmaceutical companies, including Pfizer and AstraZeneca for COVID-19 vaccine clinical trials.