Similar natural protection seen against mild and severe disease<\/p>\n<\/h3>\n
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WEDNESDAY, April 27, 2022 (HealthDay News) — Unvaccinated individuals with prior symptomatic COVID-19 have a much lower risk for acquiring recurrent COVID-19 than unvaccinated individuals without prior COVID-19 for up to nine months from the index infection, according to a research letter published online April 20 in JAMA Network Open<\/em>.<\/p>\n Jessica P. Ridgway, M.D., from the University of Chicago, and colleagues assessed the degree and duration of protection associated with natural COVID-19 immunity in unvaccinated individuals. The analysis included data from unvaccinated patients with COVID-19 symptoms tested for severe acute respiratory syndrome coronavirus 2 at 1,300 sites in the Providence Health Care System (six states) between Oct. 1, 2020, and Nov. 21, 2021 (24,043 cases [positive initial test] and 97,572 controls [negative initial test]).<\/p>\n The researchers found that 2.8 percent of controls and 0.4 percent of cases developed COVID-19. Among cases, prior COVID-19 was associated with protection of 85 percent against any recurrent COVID-19, 88 percent against hospitalization for COVID-19, and 83 percent against COVID-19 not requiring hospitalization. For up to nine months from initial infection, protection remained stable.<\/p>\n “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 six months,” the authors write.<\/p>\n