RESUMEN
BACKGROUND: Given the impact of the pandemic in Brazil, vaccination is essential to prevent illness and death. Thus, this study sought to compare, after vaccination, the circulation of SARS-CoV-2 and the response to vaccination in the least and most vaccinated municipalities of a Brazilian state during the height of the pandemic when the Omicron variant was dominant. METHODS: We tested for the SARS-CoV-2 antigen and confirmed infection using an RT-qPCR and measured IgM and IgG antibodies in fully vaccinated participants from municipalities with higher and lower vaccination rates. RESULTS: We showed that participants from the least vaccinated municipalities were more likely to have detectable IgM antibodies and a positive antigen/RT-qPCR result for SARS-CoV-2 than participants from the most vaccinated municipalities. There were no differences between the vaccines used (BNT162b2, Ad26.COV2.S, AZD1222, and CoronaVac) and antibody production. CONCLUSIONS: Our study evaluated municipal vaccination coverage and its effects on mortality, infections, and anti-SARS-CoV-2 antibodies during a critical phase of the pandemic. The results suggest that higher vaccination coverage reduces acute cases and confers higher memory antibody levels against SARS-CoV-2. Even with a full vaccination schedule, individuals living in places with low vaccination rates are more susceptible to infection.
RESUMEN
BACKGROUND: COVID-19 led to the suspension academic activities worldwide, affecting millions of students and staff. METHODS: In this study, we evaluated the presence of IgM and IgG anti-SARS-CoV-2 antibodies in an academic population during the return to classes after a one-year suspension. The study took place over five months at a Brazilian university and included 942 participants. RESULTS: We found that most participants had reactive IgG and non-reactive IgM. All received at least one dose, and 940 received two or more doses, of different COVID-19 vaccines. We obtained a higher average of memory antibodies (IgG) in participants who received the CoronaVac/ChAdOx1 combination. IgG was consistently distributed for each vaccine group, but individuals who completed the vaccination schedule had higher levels. There were no differences between antibodies and gender, presence of symptoms, and previous COVID-19 infection, but older participants (>53 years) and contacts of infected individuals had higher IgM levels. CONCLUSION: This study makes significant contributions to the assessment of antibodies in the academic environment, allowing us to infer that most participants had memory immunity and low indications of recent infection when returning to face-to-face classes, as well as demonstrating the need to monitor immunity and update vaccinations.
