COVID vaccines offer lasting protection against reinfection, studies find
A pair of studies yesterday in the New England Journal of Medicine (NEJM) suggest good, durable protection of COVID-19 vaccines against recurrent infection.Fewer reinfections among older participantsResearchers from Clalit Health Services in Tel Aviv, Israel, retrospectively analyzed the electronic health records of 83,356 recipients of at least one dose of the Pfizer/BioNTech COVID-19 vaccine after recovery from infection and 65,676 unvaccinated survivors.The observational study began on Mar 1, 2021, after the Israeli Ministry of Health approved COVID-19 vaccination for all patients who had recovered from COVID-19 3 or more months before.
All participants had recovered from a primary SARS-CoV-2 infection from Aug 23, 2020 (190 days before the study period), to May 31, 2021 (90 days after study initiation).
Average patient age was 39.3 years (range, 16 to 110).COVID-19 reinfection occurred in 354 of 83,356 vaccinated participants (0.4%; 2.5 cases per 100,000 person-days) and in 2,168 of 65,676 of their unvaccinated peers (3.3%; 10.2 per 100,000).In the 16- to 64-year age-group, 326 of 73,972 vaccinated participants (0.4%; 2.6 cases per 100,000 person-days) were reinfected, compared with 2,120 of 60,877 of their unvaccinated counterparts (3.5%; 10.8 per 100,000).
Among patients 65 years and older, reinfection occurred in 28 of 9,384 vaccinated (0.3%; 1.5 cases per 100,000 person-days) and 48 of 4,799 unvaccinated participants (1.0%; 3.0 per 100,000).
United States
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Cases: 46 252 513
Deaths: 750 423
Recovered: 0
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India
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Cases: 34 321 025
Deaths: 459 652
Recovered: 0
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Brazil
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Cases: 21 835 785
Deaths: 608 235
Recovered: 0
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United Kingdom
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Cases: 9 215 683
Deaths: 141 607
Recovered: 0
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Russia
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Cases: 8 494 589
Deaths: 237 619
Recovered: 0
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