Abstract Objective After the Covid-19 pandemics hit Brazil and sanitary measures were adopted to contain its dissemination, pediatric hospital admissions were apparently fewer than usual. The authors aimed to describe the time trends of public hospital admissions of children and adolescents due to respiratory infections (RIs) in São Paulo State, Brazil, before and after the adoption of sanitary measures to contain the dissemination of Covid-19. Methods Ecological, time-series study on the monthly average number of admissions per day of children and adolescents (< 16 years) admitted to public hospitals of São Paulo due to acute RIs between January 2008 and March 2021. Data from 2008 to 2019 were used to adjust the statistical model, while data from 2020 and 2021 were compared to the values predicted by the model. Results In 2020 and 2021, the number of hospital admissions was significantly lower than predicted by the time series. However, lethality was three times higher in these years, compared to the previous, and six times higher in patients with Covid-19, compared to those without the disease. Hospitalization costs in 2020 and 2021 were lower than in previous years. Conclusions These findings suggest that the sanitary measures adopted to contain the dissemination of Covid-19 also effectively reduce the transmission of other respiratory viruses. Policymakers and administrators can use this knowledge as a guide to planning preventative interventions that could decrease the number and severity of RIs and related hospital admissions in children and adolescents, decreasing the burden on the public health system.

Abstract With the large number of individuals infected and recovered from Covid-19, there is intense discussion about the quality and duration of the immunity elicited by SARS-CoV-2 infection, including the possibility of disease recurrence. Here we report a case with strong clinical, epidemiological and laboratorial evidence of, not only reinfection by SARS-CoV-2, but also clinical recurrence of Covid-19.