Indirect impact on number of admitted children with COVID-19 in the first three months of emergency use of two vaccines, in Rio de Janeiro, Brazil

IntroductionSince January 19, 2021, two vaccines against SARS-COV-2 are available in Brazil for emergency use for selected groups, not including children. AimTo describe indirect impact on the number of hospitalized children with COVID-19 in the first three months after beginning of emergency use of two vaccines. MethodsA retrospective study was conducted in children (0-18 years), admitted in two pediatric hospitals of Rio de Janeiro city, between January and April 2021 with confirmed COVID-19 by reverse transcription polymerase chain reaction or serological tests. Number of cases, clinical signs, symptoms and outcomes were compared with the first wave of disease (April-June 2020). A p value of less than .05 were considered was significant. ResultsThe number of total admitted patients (with all diseases) were 1097 in 2020 period, being 46 (4.2%) of them with confirmed COVID-19, and 2187 in the 2021 period, with 47 (2.1%) cases (p=0.006). Predominant respiratory symptoms were present in 29/46 (63%) as the main presentation in 2020 patients and 37/47 (78.7%) in 2021 children (p=0.09). The main symptoms were fever, cough and dyspnoea in both periods. The median of lenght of stay after diagnosis were 4 days in 2020 and 2021 (p=0.9). Just one patient died in 2021. ConclusionThere was reduction of relative percentage of admitted confirmed pediatric cases in the the first three months of emergency use of two vaccines against SARS-COV-2, but its uncertain to atribute this finding to vaccination due to high circulation of the virus in the city.