Efeito protetor da vacinação prévia contra a Covid-19: análise do desfecho cognitivo em pacientes vacinados e não vacinados

Abstract

Introduction: COVID-19 infection has been associated with persistent cognitive deficits, impacting the quality of life of affected individuals. Although vaccination has demonstrated efficacy in reducing disease severity and its sequelae, the role of vaccination in preventing post-infection cognitive deficits is still not fully understood, with a limited number of studies available. It is essential to understand whether vaccination can attenuate post-infection cognitive symptoms, and this dissertation investigates this relationship through a systematic review and an empirical comparative analysis of the cognitive performance of vaccinated and unvaccinated individuals. Methods: The dissertation was structured into two studies. The first consisted of a systematic literature review following PRISMA guidelines and registered in PROSPERO. Articles that used objective cognitive measures and compared vaccinated and unvaccinated individuals at the time of infection were included. The second study was an empirical analysis with 237 individuals previously infected with COVID-19 and 105 controls, evaluated through neuropsychological tests. Results: The systematic review identified 1,796 articles, of which only five met the inclusion criteria. Most studies found no significant association between prior vaccination and post-COVID cognition, but one study with a substantially larger sample pointed to a slight cognitive advantage in individuals with at least two doses of the vaccine. In the empirical analysis, it was observed that individuals vaccinated with two doses performed better on the Rey-Osterrieth Complex Figure Copy test and the Trail Making Test A compared to unvaccinated individuals, suggesting a possible protective effect of vaccination against cognitive deficits related to visuospatial processing, attention, and processing speed. Conclusions: Vaccination may play a role in mitigating post-COVID cognitive deficits, but the evidence remains limited and inconclusive. Methodological inconsistencies between studies and variability in the definition of vaccination status hinder the comparison of results. The findings of the empirical study contribute to the emerging literature on the subject, but further studies with greater methodological standardization and more detailed analyses of affected cognitive domains are needed to better understand the neuroprotective impact of COVID-19 immunization.