Clinical Spectrum of Severe Acute Respiratory Syndrome Coronavirus 2 Infection and Protection From Symptomatic Reinfection
Hannah E. Maier, Guillermina Kuan, Saira Saborío, Fausto Andres Bustos Carrillo, Miguel Plazaola, Carlos Barilla, Nery Sánchez, Roger López, Matt Smith, John Kubale, Sergio Ojeda, Julio C Zuniga-Moya, Bradley F. Carlson, Brenda López, Anna Gajewski, Mahboob Chowdhury, Eva Harris, Ángel Balmaseda, Aubree Gordon
Abstract
BACKGROUND: There are few data on the full spectrum of disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection across the lifespan from community-based or nonclinical settings. METHODS: We followed 2338 people in Managua, Nicaragua, aged <94 years from March 2020 through March 2021. SARS-CoV-2 infection was identified through real-time reverse transcription polymerase chain reaction (RT-PCR) or through enzyme-linked immunosorbent assay. Disease presentation was assessed at the time of infection or retrospectively by survey at the time of blood collection. RESULTS: There was a large epidemic that peaked between March and August 2020. In total, 129 RT-PCR-positive infections were detected, for an overall incidence rate of 5.3 infections per 100 person-years (95% confidence interval [CI], 4.4-6.3). Seroprevalence was 56.7% (95% CI, 53.5%-60.1%) and was consistent from age 11 through adulthood but was lower in children aged ≤10 years. Overall, 31.0% of the infections were symptomatic, with 54.7% mild, 41.6% moderate, and 3.7% severe. There were 2 deaths that were likely due to SARS-CoV-2 infection, yielding an infection fatality rate of 0.2%. Antibody titers exhibited a J-shaped curve with respect to age, with the lowest titers observed among older children and young adults and the highest among older adults. When compared to SARS-CoV-2-seronegative individuals, SARS-CoV-2 seropositivity at the midyear sample was associated with 93.6% protection from symptomatic reinfection (95% CI, 51.1%-99.2%). CONCLUSIONS: This population exhibited a very high SARS-CoV-2 seropositivity with lower-than-expected severity, and immunity from natural infection was protective against symptomatic reinfection.