Re-infection in COVID-19: Do we exaggerate our worries?

Arslan Y., Akgul F., Sevim B., VAROL Z. S., Tekin S.

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, vol.52, no.6, 2022 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 52 Issue: 6
  • Publication Date: 2022
  • Doi Number: 10.1111/eci.13767
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, BIOSIS, CAB Abstracts, EMBASE, MEDLINE, Veterinary Science Database
  • Keywords: coronavirus, COVID-19, re-infection, SARS-CoV-2, vaccination, SARS-COV-2
  • Dokuz Eylül University Affiliated: Yes


Background Protective long-term immunity following coronavirus disease 2019 (COVID-19) is unclear. The study evaluated the relationship between the vaccination status and risk factors in the re-infection of patients with a diagnosis of COVID-19 who reported to the Public Health Management System in a province in south-eastern Turkey. Methods Patients with positive results for the severe acute respiratory syndrome coronavirus 2 by the real-time reverse transcription polymerase chain reaction (RT-PCR) test in respiratory samples were defined as confirmed cases. Reinfection was diagnosed in cases with COVID-19 real-time RT-PCR positivity, with or without COVID-19-like symptoms, in at least 90 days after the first infection/disease. Results A total of 58 811 patients with the diagnosis of COVID-19 from March 11, 2020, to August 31, 2021, were included in the study. Re-infection was detected in 421 (0.07%) of all patients. The mean age of the cases was 38.0 +/- 16.0 years, and 51% of them were female. Eight (2.0%) of the cases resulted in death due to re-infection. No hospitalization or mortality was observed in fully vaccinated patients. Additionally, none of the mortal cases had completed the vaccination schedule. Conclusions We are concerned that the re-infection rates and mortality may increase due to new variant strains. Vaccination is the greatest weapon against progression to critical illness in re-infections, even with existing mutations. Therefore, it is important for those without a full vaccination schedule to be vaccinated, even if they have been previously infected.