Disease severity during SARS-COV-2 reinfection: a nationwide study - 08/04/22
Highlights |
• | SARS-CoV-2 reinfections associated with lower risk of death than first infections. |
• | Prior infection and immunisation both protect against severe disease at reinfection. |
• | Age sex and comorbidities are main risk factors for illness severity at reinfection. |
• | Different results in populations at risk of COVID-19 complication and not at risk. |
Abstract |
Objective |
We aimed to look at the burden of disease caused by SARS-COV-2 reinfections and identified potential risk factors for disease severity.
Methods |
We used national surveillance data to collect information on all SARS-CoV-2 primary infection and suspected reinfection cases between January 2020 until early May 2021. Reinfection cases were positive COVID-19 PCR or antigen test, 90 days after their first COVID-19 positive test. We collected information on case demographics, hospital and ICU admission, immunisation status and if individuals were at risk of complication for COVID-19.
Results |
Deaths reported within 28 days of testing positive were 61% (95% confidence interval: 56% to 65%) lower in suspected COVID-19 reinfection than primary infection cases. In the unvaccinated cohort, reinfections were associated with 49% (37% to 58%) lower odds of hospital admission in cases aged 50 to 65 years in the population not identified at risk of complication for COVID-19, and 34% (17% to 48%) in those at risk. ICU admission at reinfection compared to primary infection decreased 76% (55% to 87%). Individuals at risk and those aged below 50 years, who received at least 1 dose of vaccine against COVID-19, were 62% (39% to 74%) and 58% (24% to 77%) less likely to get admitted to hospital at reinfection, respectively.
Conclusion |
Prior SARS-CoV-2 infection was associated with lower odds of dying, and both prior infection and immunisation showed a protective effect against severe disease in selected populations. Older age, sex and underlying comorbidities appeared as principal risk factors for illness severity at reinfection.
Funding |
PHE/UKHSA
Le texte complet de cet article est disponible en PDF.Keywords : SARS-CoV-2, COVID-19, Reinfection, Primary infection, Disease severity, Immunisation
Plan
Vol 84 - N° 4
P. 542-550 - avril 2022 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.