The mystery of COVID-19 reinfections: A global systematic review and meta-analysis of 577 cases

BackgroundAs the COVID-19 pandemic rages on, reports on disparities in vaccine roll out alongside reinfection and reactivation from previously recovered cases have been emerging. With newer waves and variants of COVID-19, we conducted a systematic review to assess the determinants and disease spectrum of COVID-19 reinfection.

MethodsA comprehensive search covering relevant databases was conducted for observational studies reporting Polymerase Chain Reaction (PCR) confirmed infection and reinfection cases. Quality assessment tool developed by the National Institute of Health (NIH) for assessment of case series was used. Meta-analyses were performed using RevMan 5.3 for pooled proportions of findings in first infection and reinfection with 95% confidence interval (CI).

ResultsEighty-one studies reporting 577 cases were included from 22 countries. The mean age of patients was 46.2{+/-}18.9 years with males accounting for 45.8% of the study population while 179 (31.0%) cases of comorbidities were reported. The average time duration between first infection and reinfection was 63.6{+/-}48.9 days. During first infection and reinfection, fever was the most common symptom (41.4% and 36.4%, respectively) whilst anti-viral therapy was the most common treatment regimen administered (44.5% and 43.0%, respectively). Overall, comparable odds of symptomatic presentation and management were reported in the two infections. However, a higher Intensive Care Unit (ICU) admission rate was observed in reinfection compared to first infection (10 vs 3). Ten deaths were reported with 565 patients fully recovering. Respiratory failure was the most common cause of death (7/10 deaths). Seventy-two studies were determined to be of good quality whilst nine studies were of fair quality.

ConclusionAs the first global-scale systematic review of its kind, our findings support immunization practices given increased ICU admissions and mortality in reinfections. Our cohort serves as a guide for clinicians and authorities for devising an optimal strategy for controlling the pandemic.