ABSTRACT
BackgroundLittle is known about the risk of Long Covid following reinfection with SARS-CoV-2. We estimated the likelihood of new-onset, self-reported Long Covid after a second SARS-CoV-2 infection, and compared to a first infection. MethodsWe included UK COVID-19 Infection Survey participants who tested positive for SARS-CoV-2 between 1 November 2021 and 8 October 2022. The primary outcome was self-reported Long Covid 12 to 20 weeks after each infection. Separate analyses were performed for those <16 years and [≥]16 years. We estimated adjusted odds ratios (aORs) for new-onset Long Covid using logistic regression, comparing second to first infections, controlling for socio-demographic characteristics and calendar date of infection, plus vaccination status in those [≥]16 years. ResultsOverall, Long Covid was reported by those [≥]16 years after 4.0% and 2.4% of first and second infections, respectively; the corresponding estimates among those <16 years were 1.0% and 0.6%. The aOR for Long Covid after second compared to first infections was 0.72 (95% confidence interval: 0.63-0.81) for those [≥]16 years and 0.93 (0.57-1.53) for those <16 years. ConclusionsThe risk of new-onset Long Covid after a second SARS-CoV-2 infection is lower than that after a first infection for those [≥]16 years, though there is no evidence of a difference in risk for those <16 years. However, there remains some risk of new-onset Long Covid after a second infection, with around 1 in 40 of those [≥]16 years and 1 in 165 of those <16 years reporting Long Covid after a second infection.