key: cord-0316264-0ex9wcr9 authors: Araujo da Silva, A. R.; Esteves, M. D. M.; de Carvalho, B. R. R.; Souza, C. V.; Teixeira, C. H. title: Trends of COVID-19 pediatric admissions number during the first 24 weeks of COVID-19 vaccination in Rio de Janeiro, Brazil date: 2021-09-14 journal: nan DOI: 10.1101/2021.09.09.21263140 sha: 7ccbe7a0d543406dd8467e4430bd84f9ae01a36a doc_id: 316264 cord_uid: 0ex9wcr9 Objective: To describe trends of COVID-19 pediatric admissions number during the first 24 weeks of COVID-19 vaccination. Design: A retrospective study was conducted in children (0-18 years), admitted in two pediatric hospitals of Rio de Janeiro city, between January 17 and July 3, 2021 with confirmed COVID-19 by reverse transcription polymerase chain reaction or serological tests. Trends of COVID-19 pediatric admissions number during the first 24 weeks of COVID-19 vaccination in Rio de Janeiro, Brazil and the pre-vaccine period were measured by linear regression. Participants: Children admitted in pediatric hospitals in Rio de Janeiro, city, Brazil Results: The number of total admitted patients (with all diseases) were 5340 during the pre-vaccine period, being 94 (1.8%) of them with confirmed COVID-19, and 4182 children admitted during the vaccine period, with 86 confirmed COVID-19 patients (2.1 %) (p=0.29). Media of cases admitted per/week were 2.02 in pre-vaccine period and 3.6 during the first 24 weeks of COVID vaccination (p=0.009). One death was reported in the pre-vaccine period and four in the vaccine period (p=0.14). Trends of increase in the number of admitted cases were verified both in the pre-vaccine period as in the vaccine period, being more expressive in the last one. Conclusion: There was trend of increase in number of children admitted with confirmed COVID-19 during the first 24 weeks of COVID-vaccination in Rio de Janeiro, city. Considering that few people were fully vaccinated, reducing of number of admitted children with confirmed COVID-19 was not verified. Key-words: COVID 19, paediatrics, Infectious Disease Medicine. Starting in December 2020 in specific countries as United Kingdom and USA, COVID vaccination is one of the most promising strategies to control COVID-19 pandemics associated to non-pharmaceutical interventions (NPIs). 1, 2 Despite children were less affected by COVID-19, severes cases of respiratory syndrome distress and multisystem inflammatory syndrome (MIS-C) are described, causing hospitalization and deaths. 3, 4 Vaccines against SARS-COV-2 are available just for children above 12 years old age and initial analysis of a systematic vaccination progra ms verified reduction on hospital admissions and mortality in older adults. 5, 6 In Brazil and specifically in Rio de Janeiro state, COVID-19 vaccination has started in January 19, 2021 (Brazilian epidemiological week 3) and we speculate an indirect effect of adult vaccination contributing to modify the trend of number of admitted children due to confirmed COVID-19 in pediatric hospitals. Considering these aspects, our aim is to describe COVID-19 pediatric admission number, during the first 24 weeks of COVID-19 vaccination. We conducted a retrospective cohort study in two pediatric hospitals in Rio de Janeiro, city, Brazil. Both hospitals are private units destined exclusively to pediatric patients. All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this this version posted September 14, 2021. ; https://doi.org/10.1101/2021.09.09.21263140 doi: medRxiv preprint Unit 1 is a 135-bed hospital located at North zone of the city, that receives clinical and surgical patients referred from its own emergency and from other services. Unit 2 is a 39-bed hospital, located at South zone of the city, with the same profile of unit 1. Two periods were analysed: the first one comprised the first day of Brazilian In both periods studied, higher number of COVID-19 cases were detected in the city. 7 All patients admitted with COVID-19 in both hospitals were included in analysis. Children admitted but transferred to the other hospitals within the first 24h were excluded. Four vaccines were available during the first 24 weeks by emergency use in Brazil: ChAdOx1 nCoV-19, BNT162b2, Ad26.COV2.S and CoronaVac. 6 The first doses of vaccines were administered in Rio de Janeiro, in January 20, 2021, first doses of Ad26.COV2.S were administered in the city , after June 26, 2021. All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this this version posted September 14, 2021. ; https://doi.org/10.1101/2021.09.09.21263140 doi: medRxiv preprint Until July 3, 2021, the following groups received at least one dose of vaccine: persons older than 43 years and healthcare workers (all ages) with direct contact with patients. No vaccine was available for children. A patient was considered as a confirmed case of COVID-19 in the presence of positive polymerase chain reaction (PCR) or positive antigen. Positive IgM or IgG serology were considered as evidence of infection in patients with multisystem inflammatory syndrome. For epidemiological analyses, we considered the date of beginning of the symptoms. The two periods were analysed regarding the following variables: Total number of admitted patients (with all diseases), total number of admitted patients with confirmed COVID-19 and number of deaths A descriptive analysis was performed using Microsoft Excel. When appropriate, Z test was performed to compare proportions, t test for compare means and Mann-Whitney U test for continuous variables. A value of p less than .05 were considered as statistical significant. Trends of COVID admissions were measured using linear regression, considering the period studied. The study was submitted and approved by Ethics Committee of Faculty of Medicine (Universidade Federal Fluminense) and Prontobaby Group, under number 4.100.232 dated from June 20, 2020. A consent statement for the use of data from the patients or their parents or guardians were required for each children included. All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The trends of number of admitted children with confirmed COVID is showed in graph 1. Media of admitted cases/week was 2.2 in the pre-vaccine period and 3.6 during the vaccine period. All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. Until the end of August 2021, the COVID pandemics stills in course, causing more than 218 million of cases and 4,5 million of deaths around the world. 8 Considering that non-pharmaceutical interventions mitigate the spread of disease, effective vaccines are necessary to interrupt the pandemics. 2, 9 In countries like Israel and United Kingdom, in which a large percentage of adult were fully vaccinated, it was verified effectiveness against SARS-CoV-2 asymptomatic infection, symptomatic infection, and COVID-19-related hospitalisation, severe or critical hospitalisation, and death for the adult population and specific groups as healthcare-workers. 6 preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. In our study we proposed to verify trends of number of admitted children due to COVID-19, speculating an indirect positive effects of COVID-19 in Rio de Janeiro during the first 24 weeks of vaccination in the city, even considering that vaccine was not available for children. We verified that relative percentage of admitted children with confirmed COVID-19 compared with total of admission was statistically similar in pre and during vaccination period as well number of deaths. This finding corroborate that COVID-19 is a mild/moderate disease in children, causing few deaths, mainly in patients with previous disease. 3, 4 When trends of number of admitted children with confirmed children were analysed, curiously we verified more cases admitted/week during the period vaccination compared with the pre-vaccine period. Three possible reasons could explain these results: the first one is the introduction and circulation of Delta variant in the city, causing more cases including children (painel Rio de janeiro), the second one is available of more tests for COVID-19 detection in the city, mainly antigen-based tests and the last one is the few amount of population received fully vaccination. Our research was conducted in two reference pediatric hospitals of Rio de Janeiro which could be considered a limitation of the study, but considering that hospitals received patients from all neighborhood of the city, the results could reflect the true dynamics of virus circulation in the city. The second limitation is disponibility of different vaccines, with different rates of effectiveness and unknown effects for longterm protection against Delta variant, which was the most one prevalent in Rio de Janeiro at the moment of the current research. All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. We verified trends of increase in number of children admitted with confirmed COVID-19 during the first 24 weeks of COVID-vaccination in Rio de Janeiro, city. Considering that few people were fully vaccinated, reducing of number of admitted children with confirmed COVID-19 was not not verified. Modeling the impact of SARS-CoV-2 variants and vaccines on the spread of COVID-19 Ranking the effectiveness of worldwide COVID-19 government interventions Coronavirus disease 2019 (COVID-19) in children and/or adolescents: a metaanalysis A Systematic Review of Multisystem Inflammatory Syndrome in Effectiveness of the Pfizer-BioNTech and Oxford-AstraZeneca vaccines on covid-19 related symptoms, hospital All rights reserved the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this this version posted Impact and effectiveness of mRNA BNT162b2 vaccine against SARS-CoV-2 infections and COVID-19 cases, hospitalisations, and deaths following a nationwide vaccination campaign in Israel: an observational study using national surveillance data Painel Rio COVID-19 WHO Coronavirus (COVID-19) Dashboard. Available at What defines an efficacious COVID-19 vaccine? A review of the challenges assessing the clinical efficacy of vaccines against SARS-CoV-2 COVID-19 vaccine coverage in health-care workers in England and effectiveness of BNT162b2 mRNA vaccine against infection (SIREN): a prospective, multicentre, cohort study We thank to Mario Eduardo Viana and Luisa Benigno Barbosa Araujo da Silva for supporting this research. All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.