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Coronavirus disease 2019 (COVID-19) vaccines effectively protect against severe disease and death. However, the impact of the vaccine used, viral variants, and host factors on disease severity remain poorly understood. This work aimed to compare COVID-19 clinical presentations and outcomes in vaccinated and unvaccinated patients in Mexico City. From March to September 2021, clinical, demographic characteristics, and viral variants were obtained from 1014 individuals with a documented SARS-CoV-2 infection. We compared unvaccinated, partially vaccinated, and fully vaccinated patients, stratifying by age groups. We also fitted multivariate statistical models to evaluate the impact of vaccination status, SARS-CoV-2 lineages, vaccine types, and clinical parameters. Most hospitalized patients were unvaccinated. In patients over 61 years old, mortality was significantly higher in unvaccinated compared to fully vaccinated individuals. In patients aged 31 to 60 years, vaccinated patients were more likely to be outpatients (46%) than unvaccinated individuals (6.1%). We found immune disease and age above 61 years old to be risk factors, while full vaccination was found to be the most protective factor against in-hospital death. This study suggests that vaccination is essential to reduce mortality in a comorbid population such as that of Mexico.
RESUMO
Resumen: Objetivo: Evaluar la efectividad de las vacunas contra SARS-CoV-2 para evitar muerte e intubación en pacientes hospitalizados con Covid-19. Material y métodos: Se presentó un análisis de 3 565 hospitalizaciones por SARS-CoV-2 de personas mayores de 20 años de edad, reportadas con fines de salud pública por 10 hospitales de especialidad. Se comparó a los egresados por mejoría (2 094) con los fallecidos (1 471) en modelos mixtos de regresión logística ajustados por edad, sexo, número de comorbilidades y el hospital como variable aleatoria. Resultados: Un esquema completo de vacunación, con cinco tipos de vacunas disponibles, tuvo un efecto protector para muerte o intubación (RM: 0.67, IC95%: 0.54,0.83, 33% de protección); y para muerte (RM: 0.80, IC95%: 0.64,0.99, 20% de protección) estos datos se compararon con los que no habían sido vacunados. Todas las vacunas aplicadas mostraron un efecto protector con un RM<0.8, con intervalos de confianza variables. Conclusiones: El antecedente de vacunación reduce los riesgos de ser intubado y morir, aun en pacientes previamente vacunados y hospitalizados con Covid-19 grave.
Abstract: Objective: To evaluate the effectiveness of SARS-CoV-2 vaccines to avoid death and intubation in hospitalized patients with Covid-19. Materials and methods: We present an analysis of 3 565 hospitalizations for SARS-CoV-2 in people over 20 years of age, reported for public health purposes by 10 specialty hospitals, comparing those discharged for improvement (2 094) with those who died (1 471) in mixed models of logistic regression adjusted for age, sex, number of comorbidities and the reporting hospital as a random variable. Results: A complete vaccination schedule, with five types of vaccine available, had a protective effect for death or intubation (OR: 0.67, CI95%: 0.54,0.83, 33% protection) and for death (OR: 0.80, CI95%: 0.64,0.99, 20% protection) compared to those who had not been vaccinated. All the applied vaccines in the Mexican program showed a protective effect with an OR<0.8, with variable confidence intervals. Conclusions: Even in patients previously vaccinated and hospitalized with severe Covid-19, a history of vaccination reduces the risks of being intubated and dying.
RESUMO
The COVID-19 outbreak has caused over three million deaths worldwide. Understanding the pathology of the disease and the factors that drive severe and fatal clinical outcomes is of special relevance. Studying the role of the respiratory microbiota in COVID-19 is especially important as the respiratory microbiota is known to interact with the host immune system, contributing to clinical outcomes in chronic and acute respiratory diseases. Here, we characterized the microbiota in the respiratory tract of patients with mild, severe, or fatal COVID-19, and compared it to healthy controls and patients with non-COVID-19-pneumonia. We comparatively studied the microbial composition, diversity, and microbiota structure between the study groups and correlated the results with clinical data. We found differences in the microbial composition for COVID-19 patients, healthy controls, and non-COVID-19 pneumonia controls. In particular, we detected a high number of potentially opportunistic pathogens associated with severe and fatal levels of the disease. Also, we found higher levels of dysbiosis in the respiratory microbiota of patients with COVID-19 compared to the healthy controls. In addition, we detected differences in diversity structure between the microbiota of patients with mild, severe, and fatal COVID-19, as well as the presence of specific bacteria that correlated with clinical variables associated with increased risk of mortality. In summary, our results demonstrate that increased dysbiosis of the respiratory tract microbiota in patients with COVID-19 along with a continuous loss of microbial complexity structure found in mild to fatal COVID-19 cases may potentially alter clinical outcomes in patients. Taken together, our findings identify the respiratory microbiota as a factor potentially associated with the severity of COVID-19.