Dynamics of SARS-CoV-2 seroprevalence during the first year of the COVID-19 pandemic in the Northeast region of Brazil.

In this household-based seroepidemiological survey, we analyzed the dynamics of SARS-CoV-2 seroprevalence during the first year of the COVID-19 pandemic in Sergipe State, Northeast Brazil, the poorest region of the country. A total of 16,547 individuals were tested using a rapid IgM-IgG antibody test and fluorescence immunoassay (FIA). Seroprevalence rates were presented according to age, sex, and geographic region. A comparative analysis was performed between the results obtained in July 2020 (peak of the first wave), August - November 2020 (end of the first wave), and February - March 2021 (beginning of the second wave). Seroprevalence rates in the three phases were estimated at 9.3% (95% CI 8.5-10.1), 12.0% (95% CI 11.2-12.9) and 15.4% (95% CI 14.5-16.4). At the end of the first wave, there was a rise in seroprevalence in the countryside (p < 0.001). At the beginning of the second wave, we found an increase in seroprevalence among women (p < 0.001), adults aged 20 to 59 years (p < 0.001), and the elderly (p < 0.001). In this phase, we found an increase in estimates both in metropolitan areas and in the countryside (p < 0.001). This study showed an increase in SARS-CoV-2 seroprevalence over the first year of the pandemic, with approximately one in six people having anti-SARS-CoV-2 antibodies at the beginning of the second wave of COVID-19. Furthermore, our results suggest a rapid spread of COVID-19 from metropolitan areas to the countryside during the first months of the pandemic.

Surveillance of adverse events associated with 145 000 doses of COVID-19 vaccines in a Brazilian municipality.

There is a lack of real-world surveillance studies on reports of adverse events associated with COVID-19 vaccination, as well as comparative analyses of adverse events from vaccines with different platforms. This observational, descriptive, retrospective study based on secondary data describes the adverse events following immunization (AEFIs) related to the first 145 000 doses of COVID-19 vaccines delivered in Aracaju municipality, Sergipe state, northeast Brazil. Records of AEFIs were collected using the e-SUS Notifica database for January 19 to April 30, 2021. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for AEFIs and the type of COVID-19 vaccine, either CoronaVac (Sinovac-Butantan) or Oxford-AstraZeneca (Fiocruz). A total of 474 AEFIs (32.7 events/10 000 doses) from 254 individuals were reported and analyzed, and all of them were classified as non-serious. There was an association between the use of the CoronaVac vaccine and headache (OR = 2.1; 95% CI: 1.4-3.2), pain at the injection site (OR = 9.6; 95% CI: 3.9-23.8), lethargy (OR = 5.2; 95% CI: 1.8-14.8), fatigue (OR = 10.1; 95% CI: 2.4-42.3), diarrhea (OR = 4.4; 95% CI: 1.5-12.5) and cold-like symptoms (OR = 8.0; 95% CI: 1.9-34.0). However, the proportion of individuals reporting fever was higher among those who received the Oxford-AstraZeneca vaccine (OR = 3.1; 95% CI 1.5-6.4). This population-based observational study strengthens the evidence for the safety and tolerability of the CoronaVac and Oxford-AstraZeneca vaccines used against COVID-19.

Hay una carencia de estudios de vigilancia en el mundo real sobre la notificación de eventos adversos asociados a la vacunación contra la COVID-19, así como de análisis comparativos de los eventos adversos de vacunas con diferentes plataformas. En este estudio observacional, descriptivo y retrospectivo basado en datos secundarios se describen los eventos adversos supuestamente atribuibles a la vacunación o inmunización (ESAVI) relacionados con las primeras 145 000 dosis de vacunas contra la COVID-19 administradas en el municipio de Aracaju, estado de Sergipe, en la región Noreste de Brasil. Se recopilaron registros de los ESAVI del 19 de enero al 30 de abril del 2021 con la base de datos e-SUS Notifica. Se calcularon las razones de posibilidades (OR, por su sigla en inglés) y los intervalos de confianza (IC) del 95 % para los ESAVI y el tipo de vacuna contra la COVID-19 (CoronaVac [Sinovac-Butantan] o bien Oxford-AstraZeneca [Fiocruz]). Se notificaron y analizaron un total de 474 ESAVI (32,7 eventos/10 000 dosis) de 254 personas, y todos se clasificaron como no graves. Se encontró una relación entre el empleo de la vacuna CoronaVac y la cefalea (OR = 2,1; IC del 95 %: 1,4­3,2), dolor en el lugar de la inyección (OR = 9,6; IC del 95 %: 3,9­23,8), letargo (OR = 5,2; IC del 95 %: 1,8­14,8), cansancio (OR = 10,1; IC del 95 %: 2,4­42,3), diarrea (OR = 4,4; IC del 95 %: 1,5­12,5) y síntomas similares al resfriado (OR = 8,0; IC del 95 %: 1,9 a 34,0). Sin embargo, la proporción de pacientes que notificaron fiebre fue mayor entre los que recibieron la vacuna de Oxford-AstraZeneca (OR = 3,1; IC del 95 %: 1,5 a 6,4). Este estudio observacional poblacional refuerza la evidencia sobre la seguridad y tolerabilidad de las vacunas CoronaVac y Oxford-AstraZeneca empleadas contra la COVID-19.

Faltam estudos de vigilância no mundo real sobre relatórios de eventos adversos associados à vacinação contra a COVID-19, bem como análises comparativas de eventos adversos decorrentes de vacinas com diferentes plataformas. Este estudo observacional, descritivo e retrospectivo baseado em dados secundários descreve os eventos adversos pós-vacinação (EAPV) relacionados com as primeiras 145 mil doses de vacinas contra a COVID-19 entregues no município de Aracaju, capital do estado de Sergipe, na região Nordeste do Brasil. Os registros de EAPV foram coletados usando o sistema e-SUS Notifica com referência ao período de 19 de janeiro a 30 de abril de 2021. Razões de chances (odds ratios, ORs) e intervalos de confiança (IC) de 95% foram calculados para os EAPV e o tipo de vacina contra a COVID-19: CoronaVac (Sinovac-Butantan) ou Oxford-AstraZeneca (Fiocruz). Um total de 474 EAPV (32,7 eventos/10 mil doses) de 254 indivíduos foram relatados e analisados, e todos foram classificados como não graves. Houve uma associação entre o uso da vacina CoronaVac e cefaleia (OR = 2,1; IC 95%: 1,4-3,2), dor no local da injeção (OR = 9,6; IC 95%: 3,9-23,8), letargia (OR = 5,2; IC 95%: 1,8-14,8), cansaço (OR = 10,1; IC 95%: 2,4-42,3), diarreia (OR = 4,4; IC 95%: 1,5-12,5 e sintomas gripais (OR = 8,0; IC 95%: 1,9-34,0). Contudo, a proporção de indivíduos que relataram febre foi superior entre os que receberam a vacina Oxford-AstraZeneca (OR = 3,1; IC 95%: 1,5-6,4). Este estudo observacional de base populacional reforça as evidências da segurança e tolerabilidade das vacinas CoronaVac e Oxford-AstraZeneca usadas contra a COVID-19.

Seroprevalence of SARS-CoV-2 antibodies in the poorest region of Brazil: results from a population-based study.

Population-based seroprevalence studies on coronavirus disease 2019 (COVID-19) in low- and middle-income countries are lacking. We investigated the seroprevalence of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) antibodies in Sergipe state, Northeast Brazil, using rapid IgM-IgG antibody test and fluorescence immunoassay. The seroprevalence was 9.3% (95% CI 8.5-10.1), 10.2% (95% CI 9.2-11.3) for women and 7.9% (IC 95% 6.8-9.1) for men (P = 0.004). We found a decline in the prevalence of SARS-CoV-2 antibodies according to age, but the differences were not statistically significant: 0-19 years (9.9%; 95% CI 7.8-12.5), 20-59 years (9.3%; 95% CI 8.4-10.3) and ≥60 years (9.0%; 95% CI 7.5-10.8) (P = 0.517). The metropolitan area had a higher seroprevalence (11.7%, 95% CI 10.3-13.2) than outside municipalities (8.0%, 95% CI 7.2-8.9) (P < 0.001). These findings highlight the importance of serosurveillance to estimate the real impact of the COVID-19 outbreak and thereby provide data to better understand the spread of the virus, as well as providing information to guide stay-at-home measures and other policies. In addition, these results may be useful as basic data to follow the progress of COVID-19 outbreak as social restriction initiatives start to be relaxed in Brazil.