Systemic and mucosal IgA responses are variably induced in response to SARS-CoV-2 mRNA vaccination and are associated with protection against subsequent infection.

Although SARS-CoV-2 infects the upper respiratory tract, we know little about the amount, type, and kinetics of antibodies (Ab) generated in the oral cavity in response to COVID-19 vaccination. We collected serum and saliva samples from participants receiving two doses of mRNA COVID-19 vaccines and measured the level of anti-SARS-CoV-2 Ab. We detected anti-Spike and anti-Receptor Binding Domain (RBD) IgG and IgA, as well as anti-Spike/RBD associated secretory component in the saliva of most participants after dose 1. Administration of a second dose of mRNA boosted the IgG but not the IgA response, with only 30% of participants remaining positive for IgA at this timepoint. At 6 months post-dose 2, these participants exhibited diminished anti-Spike/RBD IgG levels, although secretory component-associated anti-Spike Ab were more stable. Examining two prospective cohorts we found that participants who experienced breakthrough infections with SARS-CoV-2 variants had lower levels of vaccine-induced serum anti-Spike/RBD IgA at 2-4 weeks post-dose 2 compared to participants who did not experience an infection, whereas IgG levels were comparable between groups. These data suggest that COVID-19 vaccines that elicit a durable IgA response may have utility in preventing infection. Our study finds that a local secretory component-associated IgA response is induced by COVID-19 mRNA vaccination that persists in some, but not all participants. The serum and saliva IgA response modestly correlate at 2-4 weeks post-dose 2. Of note, levels of anti-Spike serum IgA (but not IgG) at this timepoint are lower in participants who subsequently become infected with SARS-CoV-2. As new surges of SARS-CoV-2 variants arise, developing COVID-19 booster shots that provoke high levels of IgA has the potential to reduce person-to-person transmission.

Determinants of the use of health care services: multilevel analysis in the Metropolitan Region of Sao Paulo.

OBJECTIVE To evaluate the individual and contextual determinants of the use of health care services in the metropolitan region of Sao Paulo. METHODS Data from the Sao Paulo Megacity study - the Brazilian version of the World Mental Health Survey multicenter study - were used. A total of 3,588 adults living in 69 neighborhoods in the metropolitan region of Sao Paulo, SP, Southeastern Brazil, including 38 municipalities and 31 neighboring districts, were selected using multistratified sampling of the non-institutionalized population. Multilevel Bayesian logistic models were adjusted to identify the individual and contextual determinants of the use of health care services in the past 12 months and presence of a regular physician for routine care. RESULTS The contextual characteristics of the place of residence (income inequality, violence, and median income) showed no significant correlation (p > 0.05) with the use of health care services or with the presence of a regular physician for routine care. The only exception was the negative correlation between living in areas with high income inequality and presence of a regular physician (OR: 0.77; 95%CI 0.60;0.99) after controlling for individual characteristics. The study revealed a strong and consistent correlation between individual characteristics (mainly education and possession of health insurance), use of health care services, and presence of a regular physician. Presence of chronic and mental illnesses was strongly correlated with the use of health care services in the past year (regardless of the individual characteristics) but not with the presence of a regular physician. CONCLUSIONS Individual characteristics including higher education and possession of health insurance were important determinants of the use of health care services in the metropolitan area of Sao Paulo. A better understanding of these determinants is essential for the development of public policies that promote equitable use of health care services.

Determinants of the use of health care services: multilevel analysis in the Metropolitan Region of Sao Paulo / Determinantes do uso de serviços de saúde: análise multinível da Região Metropolitana de São Paulo

OBJECTIVE To evaluate the individual and contextual determinants of the use of health care services in the metropolitan region of Sao Paulo. METHODS Data from the Sao Paulo Megacity study – the Brazilian version of the World Mental Health Survey multicenter study – were used. A total of 3,588 adults living in 69 neighborhoods in the metropolitan region of Sao Paulo, SP, Southeastern Brazil, including 38 municipalities and 31 neighboring districts, were selected using multistratified sampling of the non-institutionalized population. Multilevel Bayesian logistic models were adjusted to identify the individual and contextual determinants of the use of health care services in the past 12 months and presence of a regular physician for routine care. RESULTS The contextual characteristics of the place of residence (income inequality, violence, and median income) showed no significant correlation (p > 0.05) with the use of health care services or with the presence of a regular physician for routine care. The only exception was the negative correlation between living in areas with high income inequality and presence of a regular physician (OR: 0.77; 95%CI 0.60;0.99) after controlling for individual characteristics. The study revealed a strong and consistent correlation between individual characteristics (mainly education and possession of health insurance), use of health care services, and presence of a regular physician. Presence of chronic and mental illnesses was strongly correlated with the use of health care services in the past year (regardless of the individual characteristics) but not with the presence of a regular physician. CONCLUSIONS Individual characteristics including higher education and possession of health insurance were important determinants of the use of health care services in the metropolitan area of Sao Paulo. A better understanding of these determinants is essential for the development of public policies ...

OBJETIVO Analisar os determinantes individuais e contextuais do uso de serviços de saúde na Região Metropolitana de São Paulo. MÉTODOS Foram utilizados os dados do estudo São Paulo Megacity, a versão brasileira da pesquisa multicêntrica World Mental Health Survey. Foram analisados 3.588 indivíduos adultos residentes em 69 áreas da Região Metropolitana de São Paulo, SP (38 municípios adjacentes e 31 subprefeituras do município de São Paulo), selecionados por meio de amostragem multiestratificada da população não institucionalizada. Foram ajustados modelos multinível logísticos Bayesianos para identificar os determinantes individuais e contextuais do uso de serviços de saúde nos últimos 12 meses e a presença de médico de referência para cuidados de rotina. RESULTADOS As características contextuais do local de residência (desigualdade de renda, violência e renda mediana) não apresentaram associação significativa (p > 0,05) com o uso de serviços ou com a presença de médico de referência para cuidados de rotina. A única exceção foi a associação negativa entre residir em uma área com alta desigualdade de renda e a presença de médico de referência (OR 0,77; IC95% 0,60;0,99) após controle das características individuais. O estudo apontou uma forte e consistente associação entre algumas características individuais (principalmente escolaridade e presença de plano de saúde) com o uso de serviços de saúde e ter médico de referência. A presença de doenças crônicas e mentais associou-se fortemente com o uso de serviços no último ano (independentemente de características individuais), mas não com a presença de médico de referência. CONCLUSÕES Características individuais como maior escolaridade e ter plano de saúde foram determinantes importantes do uso de serviços de saúde na Região Metropolitana de São Paulo. A melhor compreensão desses determinantes é necessária para o desenvolvimento de políticas públicas que permitam o uso equitativo dos serviços ...