Risk Factors Contributing to Reinfection by SARS-CoV-2: A Systematic Review

Highlights: What are the main findings? This comprehensive analysis meticulously examined 51 studies, pinpointing 27 that rigorously adhered to stringent criteria. The incorporation of diverse studies afforded a panoramic perspective on COVID-19 reinfection. Emphasis was placed on the effectiveness of vaccination, showcasing a remarkable risk reduction of up to 66% with the administration of two vaccine doses. What is the implication of the main finding? In spite of an overall low reinfection rate, the findings unveiled noteworthy patterns. Factors such as non-vaccination, advanced age, and the presence of comorbidities emerged as significant contributors to the likelihood of reinfection. While the review furnished valuable insights, it underscored the persistent necessity for more nuanced observational studies. Special attention was urged, particularly regarding emerging variants and the duration of immunity post-infection or post-vaccination. This article aims to systematize the evidence regarding risk factors associated with COVID-19 reinfection. We conducted a systematic review of all the scientific publications available until August 2022. To ensure the inclusion of the most recent and relevant information, we searched the PubMed and Scopus databases. Thirty studies were reviewed, with a significant proportion being analytical observational case-control and cohort studies. Upon qualitative analysis of the available evidence, it appears that the probability of reinfection is higher for individuals who are not fully immunized when exposed to a new variant, females, those with pre-existing chronic diseases, individuals aged over 60, and those who have previously experienced severe symptoms of the disease or are immunocompromised. In conclusion, further analytical observational case-control studies are necessary to gain a better understanding of the risk factors associated with SARS-CoV-2 (COVID-19) reinfection.