Characterizing altruistic motivation in potential volunteers for SARS-CoV-2 challenge trials.

In human challenge trials (HCTs), volunteers are deliberately infected with an infectious agent. Such trials can be used to accelerate vaccine development and answer important scientific questions. Starting early in the COVID-19 pandemic, ethical concerns were raised about using HCTs to accelerate development and approval of a vaccine. Some of those concerns pertained to potential exploitation of and/or lack of truly informed consent from volunteers. Specific areas of concern arose around individuals who may be unusually risk-seeking or too economically vulnerable to refuse the payments these trials provide, as opposed to being motivated primarily by altruistic goals. This pre-registered study is the first large-scale survey to characterize people who, early in the pandemic, expressed interest and intention to volunteer to participate in COVID-19 HCTs. We found that individuals expressing interest in SARS-CoV-2 HCTs exhibit consistently altruistic motivations without any special indication of poor risk perception or economic vulnerability. In finding that, early in the pandemic, COVID-19 HCTs were able to attract volunteers whose values align with the nature of these trials, and who are not unusually vulnerable to exploitation, this study may allay some ethical concerns about the volunteers interested in participating in such trials.

Coronavirus Disease 2019 (COVID-19) Vaccine Prioritization in Low- and Middle-Income Countries May Justifiably Depart From High-Income Countries' Age Priorities.

In high-income countries that were first to roll out coronavirus disease 2019 (COVID-19) vaccines, older adults have thus far usually been prioritized for these vaccines over younger adults. Age-based priority primarily resulted from interpreting evidence available at the time, which indicated that vaccinating the elderly first would minimize COVID-19 deaths and hospitalizations. The World Health Organization counsels a similar approach for all countries. This paper argues that some low- and middle-income countries that are short of COVID-19 vaccine doses might be justified in revising this approach and instead prioritizing certain younger persons when allocating current vaccines or future variant-specific vaccines.

How to overcome the stagnation of the first dose vaccine coverage curve against coronavirus disease 2019 in Brazil?

BACKGROUND: A large percentage of the population has not yet started vaccination, for which the increase in coverage is almost null. METHODS: We used segmented regression analysis to estimate trends in the first dose coverage curve. RESULTS: There has been a slowdown in the application of the first doses in Brazil since epidemiological week 36 (average percent change [APC] 0.83%, 95% confidence interval [CI] 0.75-0.91%), with a trend close to stagnation. CONCLUSIONS: It is important to develop strategies to increase access to vaccination posts. Furthermore, it is recommended to expand vaccination to children, thereby increasing the eligible population.

Ecological and environmental factors affecting transmission of sylvatic yellow fever in the 2017-2019 outbreak in the Atlantic Forest, Brazil.

BACKGROUND: Yellow fever virus (YFV) is an arbovirus that, despite the existence of a safe and effective vaccine, continues to cause outbreaks of varying dimensions in the Americas and Africa. Between 2017 and 2019, Brazil registered un unprecedented sylvatic YFV outbreak whose severity was the result of its spread into zones of the Atlantic Forest with no signals of viral circulation for nearly 80 years. METHODS: To investigate the influence of climatic, environmental, and ecological factors governing the dispersion and force of infection of YFV in a naïve area such as the landscape mosaic of Rio de Janeiro (RJ), we combined the analyses of a large set of data including entomological sampling performed before and during the 2017-2019 outbreak, with the geolocation of human and nonhuman primates (NHP) and mosquito infections. RESULTS: A greater abundance of Haemagogus mosquitoes combined with lower richness and diversity of mosquito fauna increased the probability of finding a YFV-infected mosquito. Furthermore, the analysis of functional traits showed that certain functional groups, composed mainly of Aedini mosquitoes which includes Aedes and Haemagogus mosquitoes, are also more representative in areas where infected mosquitoes were found. Human and NHP infections were more common in two types of landscapes: large and continuous forest, capable of harboring many YFV hosts, and patches of small forest fragments, where environmental imbalance can lead to a greater density of the primary vectors and high human exposure. In both, we show that most human infections (~ 62%) occurred within an 11-km radius of the finding of an infected NHP, which is in line with the flight range of the primary vectors. CONCLUSIONS: Together, our data suggest that entomological data and landscape composition analyses may help to predict areas permissive to yellow fever outbreaks, allowing protective measures to be taken to avoid human cases.

Adherence to physical contact restriction measures and the spread of COVID-19 in Brazil. / Adesão às medidas de restrição de contato físico e disseminação da COVID-19 no Brasil.

OBJECTIVE: To analyze the adherence of the population to physical contact restriction measures and the spread of COVID-19 in Brazil. METHODS: This was a web-based health survey carried out from April 24 to May 24 2020 using a chain sampling procedure. Intensity of adherence to physical contact restriction measures was analyzed according to sociodemographic characteristics, using logistic regression models to investigate associations with 'No/little adherence'. RESULTS: Of the 45,161 participants, 74.2% (73.8;74.6%) reported intense adherence to the measures. The group that did not adhere to the measures was characterized by men (31.7%), those aged 30 to 49 (36.4%), those with low education levels (33.0%), those who worked during the pandemic (81.3%), those resident in the North (28.1%) and Midwest (28.5%) regions of the country. In Brazil as a whole, there was a decrease in COVID-19 daily growth rates, from 45.4% to 5.0%. CONCLUSION: A large part of the Brazilian population adhered to physical contact restriction measures, which possibly contributed to decreasing the spread of COVID-19.

Adherence to physical contact restriction measures and the spread of COVID-19 in Brazil

Resumo Objetivo: Analisar a adesão da população às medidas de restrição de contato físico e disseminação da COVID-19 no Brasil. Métodos: Inquérito de saúde, realizado pela internet, com amostragem em cadeia, no período de 24 de abril a 24 de maio de 2020. A intensidade da adesão à restrição de contato físico foi analisada segundo características sociodemográficas, utilizando-se modelos de regressão logística para investigar associações com 'Nenhuma/pouca adesão'. Resultados: Dos 45.161 participantes, 74,2% (73,8-74,6%) relataram intensa adesão às medidas. O grupo que não aderiu às medidas foi composto homens (31,7%), com idade de 30 a 49 anos (36,4%), baixa escolaridade (33,0%), trabalhando durante a pandemia (81,3%), residentes nas regiões Norte (28,1%) e Centro-Oeste (28,5%) do país. Houve importante redução das taxas de crescimento diário, de 45,4 para 5,0%. Conclusão: Grande parte da população brasileira aderiu às medidas de restrição de contato físico, o que, possivelmente, contribuiu para reduzir a disseminação da COVID-19. Resumen Objetivo: Analizar la adhesión de los brasileños a las medidas de restricción de contacto físico y diseminación del COVID-19. Métodos: Encuesta de salud realizada por internet con muesteo em cadena entre 24 de abril y 24 de mayo de 2020. La intensidad de la adhesión a la restricción de contacto físico se analizó de acuerdo con características sociodemográficas, utilizando modelos de regresión logística para investigar asociaciones con 'Ninguna/poca adhesión'. Resultados: Participaron 45.161, de los cuales un 74,2% (73,8;74,6%) informó intensa adhesión. El grupo con poca adhesión se caracterizó por hombres (31,7%), 30-49 años (36,4%), baja educación (33,0%), que trabajaron durante la pandemia (81,3%), residiendo em las regiones Norte (28,1%) y Centro-Oeste (28,5%) del país. En Brasil hubo una reducción relevante em las tasas de crecimiento diario, del 45,4% al 5,0%. Conclusión: Gran parte de la población adhirió a las medidas de restricción de contacto físico, lo que posiblemente contribuyó a la disminución de la diseminación del COVID-19. Objective: To analyze the adherence of the population to physical contact restriction measures and the spread of COVID-19 in Brazil. Methods: This was a web-based health survey carried out from April 24 to May 24 2020 using a chain sampling procedure. Intensity of adherence to physical contact restriction measures was analyzed according to sociodemographic characteristics, using logistic regression models to investigate associations with 'No/little adherence'. Results: Of the 45,161 participants, 74.2% (73.8;74.6%) reported intense adherence to the measures. The group that did not adhere to the measures was characterized by men (31.7%), those aged 30 to 49 (36.4%), those with low education levels (33.0%), those who worked during the pandemic (81.3%), those resident in the North (28.1%) and Midwest (28.5%) regions of the country. In Brazil as a whole, there was a decrease in COVID-19 daily growth rates, from 45.4% to 5.0%. Conclusion: A large part of the Brazilian population adhered to physical contact restriction measures, which possibly contributed to decreasing the spread of COVID-19.

Is it time to talk about the end of social distancing? A joinpoint analysis of COVID-19 time series in Brazilian capitals

INTRODUCTION: Monitoring coronavirus disease (COVID-19)-related infections and deaths in Brazil is controversial, with increasing pressure to ease social distance measures. However, no evidence of a sustained, widespread fall in cases exists. METHODS We used segmented (joinpoint) regression analysis to describe the behavior of COVID-19 infections in Brazilian capital cities. RESULTS All capitals showed an exponential or a near-exponential increase in cases through May. A decline in reported cases was subsequently noted in 20 cities but was only significant for 8 (29.6%) and was followed in two by a renewed increase. CONCLUSIONS Caution is warranted when considering the relaxation of restrictions.

Broad cross-national public support for accelerated COVID-19 vaccine trial designs.

A vaccine for COVID-19 is urgently needed. Several vaccine trial designs may significantly accelerate vaccine testing and approval, but also increase risks to human subjects. Concerns about whether the public would see such designs as ethical represent an important roadblock to their implementation; accordingly, both the World Health Organization and numerous scholars have called for consulting the public regarding them. We answered these calls by conducting a cross-national survey (n = 5920) in Australia, Canada, Hong Kong, New Zealand, South Africa, Singapore, the United Kingdom, and the United States. The survey explained key differences between traditional vaccine trials and two accelerated designs: a challenge trial or a trial integrating a Phase II safety and immunogenicity trial into a larger Phase III efficacy trial. Respondents' answers to comprehension questions indicate that they largely understood the key differences and ethical trade-offs between the designs from our descriptions. We asked respondents whether they would prefer scientists to conduct traditional trials or one of these two accelerated designs. We found broad majorities prefer for scientists to conduct challenge trials (75%) and integrated trials (63%) over standard trials. Even as respondents acknowledged the risks, they perceived both accelerated trials as similarly ethical to standard trial designs. This high support is consistent across every geography and demographic subgroup we examined, including vulnerable populations. These findings may help assuage some of the concerns surrounding accelerated designs.

Toward an Early Warning System for Health Issues Related to Particulate Matter Exposure in Brazil: The Feasibility of Using Global PM2.5 Concentration Forecast Products

PM2.5 severely affects human health. Remotely sensed (RS) data can be used to estimate PM2.5 concentrations and population exposure, and therefore to explain acute respiratory disorders. However, available global PM2.5 concentration forecast products derived from models assimilating RS data have not yet been exploited to generate early alerts for respiratory problems in Brazil. We investigated the feasibility of building such an early warning system. For this, PM2.5 concentrations on a 4-day horizon forecast were provided by the Copernicus Atmosphere Monitoring Service (CAMS) and compared with the number of severe acute respiratory disease (SARD) cases. Confounding effects of the meteorological conditions were considered by selecting the best linear regression models in terms of Akaike Information Criterion (AIC), with meteorological features and their two-way interactions as explanatory variables and PM2.5 concentrations and SARD cases, taken separately, as response variables. Pearson and Spearman correlation coefficients were then computed between the residuals of the models for PM2.5 concentration and SARD cases. The results show a clear tendency to positive correlations between PM2.5 and SARD in all regions of Brazil but the South one, with Spearman’s correlation coefficient reaching 0.52 (p <0.01). Positive significant correlations were also found in the South region by previously correcting the effects of viral infections on the SARD case dynamics. The possibility of using CAMS global PM2.5 concentration forecast products to build an early warning system for pollution-related effects on human health in Brazil was therefore established. Further investigations should be performed to determine alert threshold(s) and possibly build combined risk indicators involving other risk factors for human respiratory diseases. This is of particular interest in Brazil, where the COVID-19 pandemic and biomass burning are occurring concomitantly, to help minimize the effects of PM emissions and implement mitigation actions within populations.

Is it time to talk about the end of social distancing? A joinpoint analysis of COVID-19 time series in Brazilian capitals.

INTRODUCTION: Monitoring coronavirus disease (COVID-19)-related infections and deaths in Brazil is controversial, with increasing pressure to ease social distance measures. However, no evidence of a sustained, widespread fall in cases exists. METHODS: We used segmented (joinpoint) regression analysis to describe the behavior of COVID-19 infections in Brazilian capital cities. RESULTS: All capitals showed an exponential or a near-exponential increase in cases through May. A decline in reported cases was subsequently noted in 20 cities but was only significant for 8 (29.6%) and was followed in two by a renewed increase. CONCLUSIONS: Caution is warranted when considering the relaxation of restrictions.