Observational studyFrontiers in public health2022
Risk of SARS-CoV-2 Reinfection 18 Months After Primary Infection: Population-Level Observational Study.
Observational study in Frontiers in public health, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 40 papers, 5 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
40 citing papers in PubMed, 5 syntheses or guidelines pooled it, 71 citations in OpenAlex.
- Risk Factors Contributing to Reinfection by SARS-CoV-2: A Systematic Review.Advances in respiratory medicine · 2023Pooled it
- Role of previous infection with SARS-CoV-2 in protecting against omicron reinfections and severe complications of COVID-19 compared to pre-omicron variants: a systematic review.BMC infectious diseases · 2023Pooled it
- Global prevalence of coronavirus disease 2019 reinfection: a systematic review and meta-analysis.BMC public health · 2023Pooled it
- SARS-CoV-2 Reinfection and Severity of the Disease: A Systematic Review and Meta-Analysis.Viruses · 2023Pooled it
- COVID-19 vaccines reduce the risk of SARS-CoV-2 reinfection and hospitalization: Meta-analysis.Frontiers in medicine · 2022Pooled it
- Optimal pandemic control strategies and cost-effectiveness of COVID-19 non-pharmaceutical interventions in the United States.BMC global and public health · 2025Article
- Epidemiological features and risk factors of SARS-CoV-2 reinfection: a retrospective cohort analysis in Xiamen, China.Journal of thoracic disease · 2025Article
- COVID-19 Reinfections in the City of São Paulo, Brazil: Prevalence and Socioeconomic Factors.Open forum infectious diseases · 2025Article
- Characteristics and risk factors associated with COVID-19 reinfection in Hong Kong: a retrospective cohort study.Epidemiology and infection · 2025Article
- COVID-19 vaccination, all-cause mortality, and hospitalization for cancer: 30-month cohort study in an Italian province.EXCLI journal · 2025Article
- Effectiveness of the First and Second Severe Acute Respiratory Syndrome Coronavirus 2 Vaccine Dose: A Nationwide Cohort Study From Austria on Hybrid Versus Natural Immunity.Open forum infectious diseases · 2024Article
- Should we ignore SARS-CoV-2 disease?Epidemiology and infection · 2024Article
- Evaluating the risk of SARS-CoV-2 reinfection with the Omicron or Delta variant in Wales, UK.PloS one · 2024Article
- Rate and Risk Factors of Reinfection, Recurrence, and Hospital Readmission Among SARS-Cov-2 Hospitalized Patients; a National Cohort Study.Archives of academic emergency medicine · 2024Article
- Article
- Risk of SARS-CoV-2 Reinfection 3 Years after the Start of the Pandemic: A Population-Level Observational Study.Life (Basel, Switzerland) · 2023Article
- Endemic characteristics of SARS-CoV-2 infection.Scientific reports · 2023Article
- SARS-CoV-2 reinfection: Adding insult to dysfunctional endothelium in patients with atherosclerotic cardiovascular disease.Atherosclerosis plus · 2023Review
- Predictors of SARS-CoV-2 Infection and Severe and Lethal COVID-19 after Three Years of Follow-Up: A Population-Wide Study.Viruses · 2023Article
- COVID-19 Vaccination Effectiveness in the General Population of an Italian Province: Two Years of Follow-Up.Vaccines · 2023Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors at 3 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Current data suggest that SARS-CoV-2 reinfections are rare. Uncertainties remain, however, on the duration of the natural immunity, its protection against Omicron variant, and on the impact of vaccination to reduce reinfection rates. In this retrospective cohort analysis of the entire population of an Italian region, we followed 1,293,941 subjects from the beginning of the pandemic to the current scenario of Omicron predominance (up to mid-February 2022). After an average of 277 days, we recorded 729 reinfections among 119,266 previously infected subjects (overall rate: 6.1‰), eight COVID-19-related hospitalizations (7/100,000), and two deaths. Importantly, the incidence of reinfection did not vary substantially over time: after 18-22 months from the primary infection, the reinfection rate was still 6.7‰, suggesting that protection conferred by natural immunity may last beyond 12 months. The risk of reinfection was significantly higher among females, unvaccinated subjects, and during the Omicron wave.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.