- COMPREHENSIVE META ANALYSIS FOR SCREENING TESTS FULL
- COMPREHENSIVE META ANALYSIS FOR SCREENING TESTS SERIES
Kentucky residents with previous infections who were unvaccinated had 2.34 times the odds of reinfection (OR = 2.34 95% CI = 1.58–3.47) compared with those who were fully vaccinated partial vaccination was not significantly associated with reinfection (OR = 1.56 95% CI = 0.81–3.01). Among case-patients, 20.3% were fully vaccinated, compared with 34.3% of controls ( Table 2). Among the population included in the analysis, 60.6% were female, and 204 (82.9%) case-patients were initially infected during October–December 2020 ( Table 1). Overall, 246 case-patients met eligibility requirements and were successfully matched by age, sex, and date of initial infection with 492 controls. This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy. SAS (version 9.4 SAS Institute) was used for matching and statistical analyses.
COMPREHENSIVE META ANALYSIS FOR SCREENING TESTS FULL
Using conditional logistic regression, ORs and CIs were used to compare no vaccination and partial vaccination with full vaccination among case-patients and controls.
COMPREHENSIVE META ANALYSIS FOR SCREENING TESTS SERIES
Partial vaccination was defined as receipt of ≥1 dose of vaccine, but either the vaccination series was not completed or the final dose was received <14 days before the case-patient’s reinfection date. For controls, the same definition was applied, using the reinfection date of the matched case-patient. Case-patients were considered fully vaccinated if a single dose of Janssen (Johnson & Johnson) or a second dose of an mRNA vaccine (Pfizer-BioNTech or Moderna) was received ≥14 days before the reinfection date. Case-patients and controls were matched to the KYIR database using first name, last name, and date of birth. Vaccination status was determined using data from the Kentucky Immunization Registry (KYIR). Random matching was performed to select controls when multiple possible controls were available to match per case ( 4). The report date in NEDSS was used if specimen collection date was missing. Date of initial positive test result refers to the specimen collection date, if available. Case-patients and controls were matched on a 1:2 ratio based on sex, age (within 3 years), and date of initial positive SARS-CoV-2 test (within 1 week). § Control participants were Kentucky residents with laboratory-confirmed SARS-CoV-2 infection in 2020 who were not reinfected through June 30, 2021. May and June were selected because of vaccine supply and eligibility requirement considerations this period was more likely to reflect resident choice to be vaccinated, rather than eligibility to receive vaccine. A case-patient was defined as a Kentucky resident with laboratory-confirmed SARS-CoV-2 infection in 2020 and a subsequent positive NAAT or antigen test result during May 1–June 30, 2021. The REDCap database was queried to identify previously infected persons, excluding COVID-19 cases resulting in death before May 1, 2021. NEDSS data for all Kentucky COVID-19 cases were imported into a REDCap database that contains laboratory test results and case investigation data, including dates of death for deceased patients reported to public health authorities ( 3). Kentucky residents aged ≥18 years with SARS-CoV-2 infection confirmed by positive nucleic acid amplification test (NAAT) or antigen test results † reported in Kentucky’s National Electronic Disease Surveillance System (NEDSS) during March–December 2020 were eligible for inclusion. To reduce their risk of infection, all eligible persons should be offered vaccination, even if they have been previously infected with SARS-CoV-2.* These findings suggest that among persons with previous SARS-CoV-2 infection, full vaccination provides additional protection against reinfection. Kentucky residents who were not vaccinated had 2.34 times the odds of reinfection compared with those who were fully vaccinated (odds ratio = 2.34 95% confidence interval = 1.58–3.47). This report details the findings of a case-control evaluation of the association between vaccination and SARS-CoV-2 reinfection in Kentucky during May–June 2021 among persons previously infected with SARS-CoV-2 in 2020. Although laboratory evidence suggests that antibody responses following COVID-19 vaccination provide better neutralization of some circulating variants than does natural infection ( 1, 2), few real-world epidemiologic studies exist to support the benefit of vaccination for previously infected persons.