Methods to evaluate COVID-19 vaccine effectiveness, with an emphasis on quasi-experimental approaches. / Métodos para avaliação da efetividade de vacinas para COVID-19 com ênfase em abordagens quase-experimentais.

The evaluation of vaccine effectiveness is conducted with real-world data. They are essential to monitor the performance of vaccination programmes over time, and in the context of the emergence of new variants. Until now, the effectiveness of COVID-19 vaccines has been assessed based on classic methods, such as cohort and test-negative case-control studies, which may often not allow for adequate control of inherent biases in the assignment of vaccination campaigns. The aim of this review was to discuss the study designs available to evaluate vaccine effectiveness, highlighting quasi-experimental studies, which seek to mimic randomized trials, by introducing an exogenous component to allocate to treatment, in addition to the advantages, limitations, and applicability in the context of Brazilian data. The use of quasi-experimental approaches, such as interrupted time series, difference-in-differences, propensity scores, instrumental variables, and regression discontinuity design, are relevant due to the possibility of providing more accurate estimates of COVID-19 vaccine effectiveness. This is especially important in scenarios such as the Brazilian, which characterized by the use of various vaccines, with the respective numbers and intervals between doses, applied to different age groups, and introduced at different times during the pandemic.

A avalição da efetividade de vacinas é feita com dados do mundo real e é essencial para monitorar o desempenho dos programas de vacinação ao longo do tempo bem como frente a novas variantes. Até o momento, a avaliação da efetividade das vacinas para COVID-19 tem sido baseada em métodos clássicos como estudos de coorte e caso controle teste-negativo, que muitas vezes podem não permitir o adequado controle dos vieses intrínsecos da alocação das campanhas de vacinação. O objetivo dessa revisão foi discutir os desenhos de estudo disponíveis para avaliação de efetividade das vacinas, enfatizando os estudos quase-experimentais, que buscam mimetizar os estudos aleatorizados ao introduzir um componente exógeno para atribuição ao tratamento, bem como suas vantagens, limitações e aplicabilidade no contexto dos dados brasileiros. O emprego de métodos quase-experimentais, incluindo as séries temporais interrompidas, o método de diferença em diferenças, escore de propensão, variáveis instrumentais e regressão descontínua, são relevantes pela possibilidade de gerar estimativas mais acuradas da efetividade de vacinas para COVID-19 em cenários como o brasileiro, que se caracteriza pelo uso de várias vacinas, com respectivos número e intervalos entre doses, aplicadas em diferentes faixas etárias e em diferentes momentos da pandemia.

Determinants of COVID-19 Vaccine Hesitancy in Portuguese-Speaking Countries: A Structural Equations Modeling Approach.

COVID-19 vaccine hesitancy (VH) has caused concerns due to the possible fluctuations that may occur directly impacting the control of the pandemic. In this study, we aimed to estimate the prevalence and factors associated with COVID-19 VH in Portuguese-speaking countries. We developed a web survey (N:6,843) using an online, structured, and validated questionnaire. We used Measurement Models, Exploratory Factor Analysis, Exploratory Structural Equation Models, and Confirmatory Factor Analysis for the data analysis. The overall prevalence of COVID-19 VH in Portuguese-speaking countries was 21.1%. showed a statistically significant direct effect for VH: vaccine-related conspiracy beliefs (VB) (ß = 0.886), perceived stress (PS) (ß = 0.313), COVID-19 Misinformation (MIS) (ß = 0.259) and individual responses to COVID-19 (CIR) (ß = -0.122). The effect of MIS and CIR for VH was greater among men and of PS and VB among women; the effect of PS was greater among the youngest and of VB and CIR among the oldest. No discrepant differences were identified in the analyzed education strata. In conclusion, we found that conspiracy beliefs related to the vaccine strongly influence the decision to hesitate (not to take or to delay the vaccine). Specific characteristics related to gender, age group, social and cognitive vulnerabilities, added to the knowledge acquired, poorly substantiated and/or misrepresented about the COVID-19 vaccine, need to be considered in the planning of vaccination campaigns. It is necessary to respond in a timely, fast, and accurate manner to the challenges posed by vaccine hesitancy.

Racial health inequalities and the COVID-19 pandemic Desigualdades raciais em saúde e a pandemia da Covid-19 / Racial health inequalities and the COVID-19 pandemic Las desigualdades raciales en la salud y la pandemia del Covid-19

Abstract Racism is a structural system that generates behaviors, practices, beliefs and prejudices that underlie unfair and avoidable inequalities, based on race or ethnicity. In health, racism can manifest itself in several ways, including institutional racism, which often occurs covertly. The coronavirus pandemic has been a challenge for countries with profound inequalities. In Brazil, despite the absence of information disaggregated by race or ethnicity, and even when collected, oftentimes recorded with errors;it is known that black people will suffer more sever impacts of the pandemic as well as its various negative outcomes. In this article we recall historical aspects and their relationship with the vulnerability of black population as well as suggest specific actions to combat racism and its devastating consequences in the context of COVID-19.

Cloth masks in public places: an essential intervention to prevent COVID-19 in Brazil. / Máscaras de tecido em locais públicos: intervenção essencial na prevenção da COVID-19 no Brasil.

There is increasing evidence that the use of masks is an indispensable protective measure against COVID-19, given the high transmissibility of the new coronavirus through the respiratory system, including by asymptomatic individuals. The use of cloth masks in public places has been established as a protective measure to be adopted alongside social distancing and hand hygiene. This narrative review aims to systematize the scientific evidence that informs the widespread use of cloth masks as a preventive measure against COVID-19 and to describe the evolution of positions contrary to or in favor of its use outside the home, in view of the advance of the new coronavirus pandemic globally. The scientific articles, technical notes, governmental decrees and other documents analyzed indicate that widespread use of masks has the potential to reduce the spread of the new coronavirus. We recommend that the Brazilian government adopt strategies to increase the supply of reusable cloth masks to the public, especially to vulnerable populations and to support studies on the impact of this measure to control the pandemic in the country. Finally, it is imperative to ensure that use of masks does not exacerbate stigmatization of racial groups that already face prejudice.

Acumulam-se evidências de que o uso de máscaras é uma medida indispensável de proteção à COVID-19, devido ao alto poder de transmissão do novo coronavírus por via respiratória, inclusive por indivíduos assintomáticos. Por sua vez, o uso das máscaras de tecido em locais públicos tem se consolidado como medida adicional de proteção às medidas de distanciamento social e higienização das mãos. Objetivou-se sistematizar as evidências científicas que justificam o amplo uso de máscaras de tecido como prevenção à COVID-19 e descrever a evolução dos posicionamentos contrários ou favoráveis ao seu uso em ambientes extradomiciliares, diante do avanço da pandemia do novo coronavírus pelo mundo. A triagem de artigos e documentos oficiais do Brasil e de outros países indica que o uso de máscaras em locais públicos tornou-se uma intervenção essencial graças ao potencial de reduzir a velocidade de propagação do novo coronavírus. Recomenda-se que o poder público adote estratégias para aumentar a oferta deste produto e fomente estudos para avaliação do impacto da medida no controle da pandemia no Brasil. É imperativo assegurar disponibilidade de máscaras a grupos socioeconomicamente desfavorecidos e garantir que determinados grupos raciais não sejam estigmatizados diante do uso de máscaras em ambientes extradomiciliares.