Journal of Medical Microbiology and Infectious Diseases

en COVID-19 in the State of São Paulo, Brazil: Epidemiological Analysis and Ongoing Challenges Infectious diseases and public health Infectious diseases and public health Original article Original article The COVID-19 pandemic, which began in early 2020, became a challenge for healthcare systems, especially in Brazil and the state of São Paulo. Non-pharmaceutical interventions, such as lockdowns and face masks, helped reduce transmission when combined with testing and tracing but were not sufficient alone to prevent high case numbers and deaths. In May 2023, due to the sustained decline in severe cases and deaths, and an increase in global immunity through vaccination and prior infection, the World Health Organization (WHO) declared that COVID-19 no longer constituted a Public Health Emergency of International Concern (PHEIC). Despite this change in status, the pandemic persists, and the emergence of new SARS-CoV-2 variants continues to highlight the need for ongoing vaccination efforts. Additionally, post-acute sequelae of SARS-CoV-2 infection—commonly referred to as long COVID—have affected a significant portion of the infected population, adding to the burden on public health systems. Given this complex scenario, the present study presents a comparative epidemiological analysis of COVID-19 in São Paulo state across three key phases: pre-vaccination, mass vaccination, and the post-PHEIC period. Public data indicated that although immunization campaigns contributed to reduced cases, hospitalizations, and deaths, COVID-19 still caused more deaths than most infectious diseases during the analyzed period. The persistence of the pandemic occurred concurrently with declining vaccination coverage following the PHEIC declaration. To address this ongoing public health challenge, more effective policies are needed, including immediate sustained vaccination efforts, variant surveillance, public awareness campaigns, and long-term health system strengthening.   COVID-19, Pandemic, SARS-CoV-2, São Paulo, Vaccination, World Health Organization 185 196 http://jommid.pasteur.ac.ir/browse.php?a_code=A-10-356-4&slc_lang=en&sid=1 Alessandra Paiva Almeida alepaivaalmeida@gmail.com 0009-0000-8270-0710 No 1Paulista School of Medicine, Federal University of São Paulo (Universidade Federal de São Paulo – UNIFESP), São Paulo, Brazil; 2Department of Health Informatics, Paulista School of Medicine, Federal University of São Paulo (UNIFESP), São Paulo, Brazil André Massahiro Shimaoka andre.shimaoka@unifesp.br 0000-0002-9400-8083 No Department of Health Informatics, Paulista School of Medicine, Federal University of São Paulo (UNIFESP), São Paulo, Brazil Paulo Bandiera Paiva paiva@unifesp.br 0000-0001-9409-3970 No Department of Health Informatics, Paulista School of Medicine, Federal University of São Paulo (UNIFESP), São Paulo, Brazil Luciano Lopes luciano.lopes@unifesp.br 0000-0002-0284-2821 Yes Department of Health Informatics, Paulista School of Medicine, Federal University of São Paulo (UNIFESP), São Paulo, Brazil