Subsequent Vaccination Cuts Risk for COVID-19 Reinfection

THURSDAY, March 3, 2022 (HealthDay News) -- For patients who have recovered from COVID-19, the risk for recurrent infection is reduced with receipt of at least one dose of the BNT162b2 vaccine, according to a study published online Feb. 16 in the New England Journal of Medicine.

Ariel Hammerman, Ph.D., from Clalit Health Services in Tel Aviv, Israel, and colleagues reviewed electronic medical records from a large health care organization in Israel to assess reinfection rates in patients who had recovered from severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection before COVID-19 vaccination in a retrospective cohort study. Reinfection rates were compared for patients who subsequently received the BNT162b2 vaccine and those who were not vaccinated between March 1 and Nov. 26, 2021. Data were included for 149,032 patients who had recovered from SARS-CoV-2 infection, 56 percent of whom received subsequent vaccination.

The researchers found that reinfection occurred in 354 and 2,168 of the vaccinated and unvaccinated cases (2.46 versus 10.21 cases per 100,000 persons per day), respectively. Vaccine effectiveness was estimated at 82 and 60 percent among patients aged 16 to 64 years and 65 years and older, respectively. There was no significant difference observed in vaccine effectiveness for one versus two doses.

"The evidence that was gathered in this study during a surge of the delta variant in Israel supports a public health policy of vaccinating patients who have recovered from COVID-19, particularly in places where the delta variant is still of concern," the authors write.

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