Eventos supostamente atribuíveis à vacinação ou imunização contra a COVID-19

Abstract

Introduction: With the health crisis triggered by the new coronavirus SARS-CoV-2, vaccines against COVID-19 were developed and proved to be effective in terms of morbidity and mortality due to the disease, however, it is still necessary to advance in the quantification and characterization of Events Supposedly Attributable to Vaccination or Immunization (ESAVI) against COVID-19. Objective: The objectives of this study were to analyze the incidence of ESAVI against COVID-19 in Brazil and to analyze the risk of Adverse Events Following Immunization (AEFI) against COVID-19 between developed and developing countries. Methods: This dissertation included two methodological designs, an analytical cross-sectional study for objective one and a systematic review with meta-analysis for the second objective. For the observational approach, secondary data obtained from the e-SUS Notifica System and the Vacivida System were used. The investigation covered demographic, clinical and epidemiological variables present in the records of ESAVI reported in the Brazilian population in the year 2021. The cumulative incidence of events and the proportion of signs and symptoms (among closed reports) per 100,000 administered doses was calculated as the measure of interest. As for the systematic review of the literature with meta-analysis, after careful definition of the eligibility criteria, elaboration and registration of the review protocol in the Próspero database, there was a search for articles in the EMBASE, PubMed/MEDLINE and SCOPUS databases. Phases one and two had two independent reviewers and a third reviewer to resolve disagreements. During the risk of bias check step, a fourth reviewer was included to assist in consensus. The extracted data were pooled, with heterogeneity and sensitivity among studies assessed. Effect estimates were expressed as relative risks, with 95%

confidence intervals, using RevMan software version 5.4. Results: With a cross- sectional study, it was possible to identify a low accumulated incidence of AEFI/COVID- 19 in Brazil (0.038%), with a predominance of non-severe, female gender, white

people, age 30 to 39 years, evolution to cure without sequelae and the South and Southeast regions of the Brazil. The most common symptoms were headache and fever, and the most common System Organ Class was general. In the systematic review, the most common symptoms worldwide were pain, headache and myalgia. it was possible to identify that developed countries have a higher relative risk of developing an AEFI/COVID-19 compared to developing countries, with no justification found in the literature. Conclusion: It appears that in 2021 there was a heterogeneous

distribution of AEFI/COVID-19 in Brazil, characterized by low incidence and non- seriousness of cases. Underreporting in Brazil and in other countries around the world

is a problem to be faced in the context of safe immunization. Worldwide, the low gravity standard of AEFI/COVID-19 persists; However, developed countries have exhibited a higher relative risk of these events, which remains unexplained in the literature to date. Despite the rapid development, emergency use and subsequent application of mass immunizations of vaccines against COVID-19, the results of the study corroborate the viability and relevance of vaccines, as well as the low severity of most adverse events post-vaccination against COVID-19, so many in the developed countries as well as in developing countries.