SARS-CoV-2 Reinfection Cases in a Household-Based Prospective Cohort in Rio de Janeiro.

This was a household-based prospective cohort study conducted in Rio de Janeiro, in which people with laboratory-confirmed coronavirus disease 2019 (COVID-19) and their household contacts were followed from April 2020 through June 2022. Ninety-eight reinfections were identified, with 71 (72.5%) confirmed by genomic analyses and lineage definition in both infections. During the pre-Omicron period, 1 dose of any COVID-19 vaccine was associated with a reduced risk of reinfection, but during the Omicron period not even booster vaccines had this effect. Most reinfections were asymptomatic or milder in comparison with primary infections, a justification for continuing active surveillance to detect infections in vaccinated individuals. Our findings demonstrated that vaccination may not prevent infection or reinfection with severe acute respiratory syndrome coronavirus 2 (SARS CoV-2). Therefore we highlight the need to continuously update the antigenic target of SARS CoV-2 vaccines and administer booster doses to the population regularly, a strategy well established in the development of vaccines for influenza immunization programs.

The Role of Children in Household Transmission of SARS-CoV-2 Across Four Waves of the Pandemic.

BACKGROUND: It is important to understand the dynamics of SARS-CoV-2 transmission in close-contact settings such as households. We hypothesized that children would most often acquire SARS-CoV-2 from a symptomatic adult caregiver. METHODS: This prospective cohort study was conducted from April 2020 to July 2022 in a low-resource, urban settlement in Brazil. We recruited families who brought their children to a public clinic. We collected nasopharyngeal and oral swabs from household members and tracked symptoms and vaccination. RESULTS: In total, 1256 participants in 298 households were tested for SARS-CoV-2. A total of 4073 RT-PCR tests were run with 893 SARS-CoV-2 positive results (21.9%). SARS-CoV-2 cases were defined as isolated cases (N = 158) or well-defined transmission events (N = 175). The risk of household transmission was lower if the index case was a child (OR: 0.3 [95% CI: 0.16-0.55], P < .001) or was vaccinated (OR: 0.29 [95% CI: 0.1-0.85], P = .024), and higher if the index was symptomatic (OR: 2.53 [95% CI: 1.51-4.26], P < .001). The secondary attack rate for child index cases to child contacts was 0.29, whereas the secondary attack rate for adult index cases to child contacts was 0.47 (P = .08). CONCLUSIONS: In this community, children were significantly less infectious to their household contacts than adolescents or adults. Most children were infected by a symptomatic adult, usually their mother. There was a double benefit of vaccination as it protected the vaccine from severe illness and prevented onward transmission to household contacts. Our findings may also be valid for similar populations throughout Latin America.

[Vaccines and social media: a debate around vaccines on Instagram and Facebook during the COVID-19 pandemic (2020-2021)]. / Vacinas e redes sociais: o debate em torno das vacinas no Instagram e Facebook durante a pandemia de COVID-19 (2020-2021).

Considering that the Internet and especially social media work as a locus for the circulation of information on COVID-19, this study aimed to assess the attention given to the vaccine theme on Instagram and Facebook in posts throughout two years of pandemic, identifying the temporality in which discussion about the different immunizing agents in social media and highlighting the actors who permeated the discussions on the subject. Data were collected using the CrowdTangle graphical interface, based on search terms in Portuguese related to vaccines approved for use in Brazil and it included posts from public Facebook pages and open Instagram profiles made from January 1st, 2020, to December 31st, 2021. The database included 3,876,408 posts (2,901,457 on Facebook and 974,952 on Instagram). The results showed an alternation of Pfizer, CoronaVac, AstraZeneca, and Janssen vaccines as the focus of discussion, following the public debate established in the country around the dilemmas and advances related to the development, production, distribution, and application of immunizing agents. References to institutions involved in the acquisition and production of immunizing agents were also identified, such as the Brazilian Ministry of Health, the Butantan Institute, and the Oswaldo Cruz Foundation, present among the thousand social actors that most generated comments from users in both networks. It was evidenced that the debate on immunizing agents, in the analyzed channels and period, was permeated by social media related to journalism and politicians and celebrities' pages and profiles.

Tendo em vista que a Internet e, em especial, as redes sociais funcionam como lócus para a circulação de informações sobre a COVID-19, o objetivo deste estudo foi verificar a atenção dispensada à temática das vacinas no Instagram e Facebook em postagens feitas ao longo de dois anos de pandemia, identificando a temporalidade em que a discussão sobre os diferentes imunizantes nas redes sociais ocorreu e apontando atores que permearam as discussões envolvendo o tema. A coleta de dados foi feita pela interface gráfica do CrowdTangle, a partir de termos de consulta em português relacionados às vacinas aprovadas para uso no Brasil e contemplou postagens de páginas públicas no Facebook e perfis abertos no Instagram feitas de 1º de janeiro de 2020 a 31 de dezembro de 2021. O banco de dados analisado possui 3.876.408 publicações (2.901.457 no Facebook e 974.952 no Instagram). Os resultados evidenciaram uma alternância das vacinas Pfizer, CoronaVac, AstraZeneca e Janssen como foco de discussão, acompanhando temporalmente o debate público que se estabeleceu no país em torno dos dilemas e avanços relativos ao desenvolvimento, à produção, à distribuição e à aplicação dos imunizantes. Também foram identificadas referências às instituições envolvidas na aquisição e produção dos imunizantes, como o Ministério da Saúde, o Instituto Butantan e a Fundação Oswaldo Cruz (Fiocruz), presentes entre os mil atores sociais que mais despertaram comentários por parte dos usuários em ambas as redes. Evidenciou-se que o debate sobre imunizantes, nos canais e no período analisados, foi permeado por meios de comunicação ligados ao jornalismo, além de páginas e perfis ligados a políticos e celebridades.

Dado que Internet y, en particular, las redes sociales funcionan como espacios de circulación de la información sobre el COVID-19, el objetivo de este estudio fue verificar la atención prestada al tema de las vacunas en Instagram y Facebook en los posts realizados a lo largo de dos años de pandemia, identificando la temporalidad en que se produjo la discusión sobre los diferentes inmunizantes en las redes sociales y señalando los actores que permeaban las discusiones que involucraban el tema. La recopilación de datos se realizó mediante la interfaz gráfica de CrowdTangle, a partir de términos de consulta en portugués relacionados con las vacunas aprobadas para su uso en Brasil y contempló publicaciones de páginas públicas en Facebook y perfiles abiertos en Instagram realizadas desde el 1º de enero de 2020 hasta el 31 de diciembre de 2021. La base de datos analizada cuenta con 3.876.408 publicaciones (2.901.457 en Facebook y 974.952 en Instagram). Los resultados mostraron una alternancia de las vacunas de Pfizer, CoronaVac, AstraZeneca y Janssen como foco de discusión, siguiendo temporalmente el debate público que se estableció en el país en torno a los dilemas y avances relacionados con el desarrollo, la producción, la distribución y la aplicación de los inmunizantes. También se identificaron referencias a instituciones involucradas en la adquisición y producción de inmunizantes, como el Ministerio de Salud de Brasil, el Instituto Butantan y la Fundación Oswaldo Cruz, presentes entre los mil actores sociales que más despertaron comentarios de los usuarios en ambas redes. Fue evidente que el debate sobre los inmunizadores, en los canales y período analizados, estuvo permeado por medios vinculados al periodismo, además de páginas y perfiles vinculados a políticos y celebridades.

Incidence of SARS-CoV-2 over four epidemic waves in a low-resource community in Rio de Janeiro, Brazil: A prospective cohort study.

Background: Incidence rates of SARS-CoV-2 infections in low-resource communities can inform vaccination strategies and non-pharmaceutical interventions (NPIs). Our objective was to estimate incidence over four epidemic waves in a slum in Rio de Janeiro, a proxy for economically deprived areas in the Global South. Methods: Prospective cohort of children and household contacts screened for SARS-CoV-2 by PCR and serology (IgG). The incidence density of PCR positive infections estimated for each wave - the first wave, Zeta, Gamma and Delta - was compared to an index combining NPIs and vaccination coverage. Findings: 718 families and 2501 individuals were enrolled, from May 2020 to November 2021. The incidence density of SARS-CoV-2 infection due to the first wave was 2, 3 times that of the other waves. The incidence among children was lower than that of older participants, except in later waves, when vaccination of the elderly reached 90%. Household agglomeration was significantly associated with incidence only during the first wave. Interpretation: The incidence of infection greatly exceeded rates reported in similar cohorts. The observed reduction in incidence in the elderly during the Delta variant wave, in spite of the rollback of NPIs, can be attributed to increased vaccine coverage. The high incidence in young people reinforces the importance of vaccination in this age group, a policy that has yet to receive the full support of some sectors of society. Funding: UK Medical Research Council, Foundation for the Advancement of Science of the State of Rio de Janeiro, National Council for Scientific and Technological Development.

ArboAlvo: stratification method for territorial receptivity to urban arboviruses.

OBJECTIVE: To present the urban arboviruses (dengue, zika and chikungunya) stratification methodology by the territorial receptivity Index, an instrument for the surveillance and control of these diseases, which considers the heterogeneity of an intra-municipal territory. METHODS: Ecological study that uses as unit of analysis the areas covered by health centers in Belo Horizonte. For the development of a territorial receptivity index, indicators of socio-environmental determination of urban arboviruses were selected in order to integrate the analysis of main components. The resulting components were weighted by the analytic hierarchy process and combined via map algebra. RESULTS: The territorial receptivity index showed great heterogeneity of urban infrastructure conditions. The areas classified with high and very high receptivity correspond to approximately 33% of the occupied area and are mainly concentrated in the administrative planning regions of East, Northeast, North, West, and Barreiro, especially in areas surrounding the municipality. When the density of dengue cases and Aedes eggs, from 2016, were superimposed with the stratification by the index of territorial receptivity to urban arboviruses, areas of very high receptivity had a high density of cases and Aedes eggs - higher than that observed in other areas of the city, which corresponds to a very small percentage of the municipal territory (13.5%). CONCLUSION: The analyses indicate the need for the development of adequate surveillance and control actions for each context, overcoming the logic of homogeneous allocation throughout the territory.

ArboAlvo: stratification method for territorial receptivity to urban arboviruses / ArboAlvo: método de estratificação da receptividade territorial às arboviroses urbanas

ABSTRACT OBJECTIVE To present the urban arboviruses (dengue, zika and chikungunya) stratification methodology by the territorial receptivity Index, an instrument for the surveillance and control of these diseases, which considers the heterogeneity of an intra-municipal territory. METHODS Ecological study that uses as unit of analysis the areas covered by health centers in Belo Horizonte. For the development of a territorial receptivity index, indicators of socio-environmental determination of urban arboviruses were selected in order to integrate the analysis of main components. The resulting components were weighted by the analytic hierarchy process and combined via map algebra. RESULTS The territorial receptivity index showed great heterogeneity of urban infrastructure conditions. The areas classified with high and very high receptivity correspond to approximately 33% of the occupied area and are mainly concentrated in the administrative planning regions of East, Northeast, North, West, and Barreiro, especially in areas surrounding the municipality. When the density of dengue cases and Aedes eggs, from 2016, were superimposed with the stratification by the index of territorial receptivity to urban arboviruses, areas of very high receptivity had a high density of cases and Aedes eggs - higher than that observed in other areas of the city, which corresponds to a very small percentage of the municipal territory (13.5%). CONCLUSION The analyses indicate the need for the development of adequate surveillance and control actions for each context, overcoming the logic of homogeneous allocation throughout the territory.

RESUMO OBJETIVO Apresentar a metodologia de estratificação das arboviroses urbanas (dengue, zika e chikungunya) pelo índice de receptividade territorial, instrumento de vigilância e controle dessas doenças que considera a heterogeneidade territorial intramunicipal. MÉTODOS Estudo ecológico que utiliza como unidade de análise as áreas de abrangência dos centros de saúde de Belo Horizonte (MG). Para a construção do índice de receptividade territorial foram selecionados indicadores de determinação socioambiental das arboviroses urbanas a fim de integrar à análise de componentes principais. As componentes resultantes foram ponderadas por análise de processos hierárquicos e agregadas por meio de álgebra de mapas. RESULTADOS O índice de receptividade territorial evidenciou grande heterogeneidade das condições de infraestrutura urbana. As áreas classificadas como alta e muito alta receptividade correspondem a aproximadamente 33% da área ocupada e se concentram sobretudo nas regiões de planejamento administrativo Leste, Nordeste, Norte, Oeste e Barreiro, principalmente em áreas limítrofes do município. Quando sobrepostas à densidade de casos de dengue e de ovos de Aedes em 2016, a estratificação pelo índice de receptividade territorial às arboviroses urbanas demonstra que áreas de muito alta receptividade apresentam uma densidade de casos, bem como de ovos de Aedes superior àquela observada nas demais áreas da cidade, o que corresponde a um percentual bastante reduzido do território municipal (13,5%). CONCLUSÕES As análises indicam a necessidade do desenvolvimento de ações de vigilância e controle adequadas para cada contexto, superando, assim, a lógica de alocação homogênea em todo o território.