ABSTRACT
Objetivo: Evaluar el efecto protector de la vacuna para SARS-CoV-2 para hospitalizaciones por COVID-19 durante la cuarta ola epidémica en Querétaro, México. Métodos: Diseño de cohorte retrospectiva en pacientes con COVID-19 durante la cuarta ola (19 de diciembre de 2021 al 9 de enero de 2022). Grupos expuestos, antecedente de vacuna anti COVID-19 (vacuna de adenovirus modificado genéticamente y vacuna de ácido ribonucleico mensajero), grupo no expuesto, no vacuna. El diagnóstico de COVID-19 se realizó con la prueba antigénica rápida en exudado orofaringeo, prueba practicada entre el primero y quinto día del inicio de sintomatología. Se incluyeron todos los pacientes que acudieron al servicio de salud por sintomatología, con prueba positiva y dos dosis de la vacuna. El análisis estadístico incluyó chi cuadrada, riesgo relativo e intervalo de confianza para riesgo relativo. Resultados: Se estudiaron 52 pacientes con vacuna de adenovirus modificado genéticamente, 119 con vacuna de ácido ribonucleico mensajero y 336 pacientes no vacunados. En pacientes no vacunados la incidencia de hospitalización fue 62,2%, en pacientes con vacuna adenovirus modificado genéticamente la hospitalización fue 23,1% (p<0.001), riesgo relativo de 0,37 (IC 95%; 0,22-0,61); y en pacientes con vacuna de ácido ribonucleico mensajero la incidencia de hospitalización fue 1,7% (p<0.001), riesgo relativo de 0,03 (IC 95%; 0,006-0,10). Conclusiones: La vacuna anti COVID-19 en el ámbito poblacional es efectiva para evitar hospitalización en pacientes que presentan cuadro agudo de COVID-19 en la cuarta ola.
Objective: To assess the protective effect of the vaccine against SARS-CoV-2 upon hospitalizations due to COVID-19 during the fourth epidemic wave in Queretaro, Mexico. Methods: This investigation was designed as a retrospective cohort study in patients with COVID-19 during the fourth wave of the epidemic (December 19th, 2021, to January 9th, 2022). The exposed group consisted in those subjects who had received a vaccine against COVID-19 (genetically modified adenovirus vaccine and messenger ribonucleic acid vaccine); and the non-exposed group consisted in those people who were not vaccinated. Diagnosis of COVID-19 was made with a rapid antigenic test in oropharyngeal exudate, and the test was performed between the first and fifth day after the onset of symptoms. All patients who came to healthcare facilities because of symptoms, with a positive test and having received two doses of the vaccine. Statistical analysis included chi-square, relative risk, and confidence intervals (CI) for the relative risk. Results: Fifty-two patients who received a genetically modified vaccine, 119 who received a messenger ribonucleic acid vaccine, and 336 non vaccinated subjects were included in the study. The frequency of hospitalization was 62,2% in non-vaccinated persons, this rate was 23,1% (p<0.001), and relative risk was 0,37 (95% CI; 0,22-0,61) in those who received a genetically modified adenovirus vaccine, and it was 1.7% (p<0.001), and relative risk was 0,03 (95% CI; 0,006-0,10) in those who received the messenger ribonucleic acid vaccine. Conclusions: From a population point of view, the vaccine against COVID-19 was effective for preventing hospitalization in patients with acute COVID-19 disease during the fourth epidemic wave.