Vaccination impact: mortality and time shift to COVID-19 maximum severity in hospitalized patients. An Argentine multicenter registry.

INTRODUCTION: The COVID-19 vaccine became an effective instrument to prevent severe SARS-CoV-2 infections. However, 5% of vaccinated patients will have moderate or severe disease. OBJECTIVE: to compare mortality and days between the symptom onset to the peak disease severity, in vaccinated vs. unvaccinated COVID-19 hospitalized patients. METHODS: Retrospective observational study in 36 hospitals in Argentina. COVID-19 adults admitted to general wards between January 1, 2021, and May 31, 2022 were included. Days between symptoms onset to peak of severity were compared between vaccinated vs. unvaccinated patients with Cox regression, adjusted by Propensity Score Matching (PSM). Results in patients with one and two doses were also compared. RESULTS: A total of 3663 patients were included (3001 [81.9%] unvaccinated and 662 [18%] vaccinated). Time from symptom onset to peak severity was 7 days (IQR 4-12) vs. 7 days (IQR 4-11) in unvaccinated and vaccinated. In crude Cox regression analysis and matched population, no significant differences were observed. Regarding mortality, a Risk Ratio (RR) of 1.51 (IC95% 1.29-1.77) was observed in vaccinated patients, but in the PSM cohort, the RR was 0.73 (IC95% 0.60-0.88). RR in patients with one COVID-19 vaccine dose in PSM adjusted population was 0.7 (IC95% 0.45-1.03), and with two doses 0.6 (IC95% 0.46-0.79). DISCUSSION: The time elapsed between the onset of COVID-19 symptoms to the highest severity was similar in vaccinated and unvaccinated patients. However, hospitalized vaccinated patients had a lower risk of mortality than unvaccinated patients.

Introducción: A pesar de la eficacia de la vacuna contra el COVID-19 el 5% de los pacientes vacunados presentaran una enfermedad moderada o grave. El objetivo del presente estudio fue comparar los días entre el inicio de los síntomas y la gravedad máxima de la enfermedad, en pacientes con COVID-19 vacunados vs. no vacunados. Métodos: Estudio observacional retrospectivo en 36 hospitales de Argentina. Se incluyeron adultos con COVID-19 hospitalizados entre el 1/01/2021 y 31/5/2022. Se recolectaron datos demográficos, comorbilidades y progresión clínica de la enfermedad. Se compararon los días entre el inicio de los síntomas y el pico de gravedad entre vacunados y no vacunados mediante regresión de Cox, ajustada por emparejamiento por Propensity Score Matching (PSM). En un análisis de subgrupos, se compararon los resultados en pacientes con una y dos dosis de vacuna. Resultados: Se incluyeron 3663 pacientes (3001 [81.9%] no vacunados y 662 [18%] vacunados). El tiempo transcurrido desde el inicio de los síntomas hasta el pico de gravedad fue de 7 días (IQR 4 - 12) en no vacunados, y de 7 días (IQR 4-11) en vacunados. Tanto en el análisis de regresión de Cox crudo como en el ajustado, no se observaron diferencias significativas entre ambos grupos (HR ajustado 1.08 [IC 95% 0.82-1.4; p = 0.56]). En cuanto a la mortalidad, el Riesgo Relativo (RR) fue 1.51 (IC95% 1.29-1.77) en los pacientes vacunados, pero en la cohorte ajustada por Propensity Score, el RR fue de 0.73 (IC95% 0.60-0.88). El RR en el grupo con una dosis de vacuna COVID-19 en el análisis PSM fue 0.7 (IC95% 0.45-1.03), y con dos dosis 0.6 (IC95% 0.46-0.79). Discusión: El tiempo entre el inicio de los síntomas de COVID-19 y el pico de severidad fue igual en vacunados y no vacunados. Sin embargo, los pacientes vacunados hospitalizados presentaron menor mortalidad tras el ajuste por confundidores.

Pandemic influenza A/H1N1 virus infection in solid organ transplant recipients: a multicenter study.

BACKGROUND: The 2009 novel influenza A/H1N1 virus pandemic did not spare solid organ transplant (SOT) recipients. We aimed to describe the behavior of pandemic influenza infection in a group of SOT recipients in Argentina. METHODS: Data from 10 transplant (Tx) centers were retrospectively collected for SOT that presented with a respiratory illness compatible with pandemic influenza A infection, between May and September 2009. Cases were defined as suspected, probable, or confirmed according to diagnostic method. RESULTS: Seventy-seven cases were included. No significant differences in presenting symptoms, pulmonary infiltrates, and graft involvement were found among 35 suspected, 19 probable, and 23 confirmed cases. The 33 ambulatory cases had significantly more sore throat and headache when compared with 34 cases admitted to medical ward (MW) and 10 admitted to intensive care unit (ICU), 9 of whom required ventilatory support. MW and ICU cases had significantly more dyspnea, hypoxemia, pulmonary infiltrates, and graft dysfunction. Time from onset of symptoms to first visit and to treatment was significantly longer in MW and ICU cases (P=0.008). Coinfections were found in six cases. Most cases received oseltamivir for 5 to 10 days. Six patients (7.8%) died from viral infection at a median of 15 days from admission. No differences in outcome were seen related to the transplanted organ, the immunosuppressive regimen, time from Tx, or confirmation of diagnosis. CONCLUSIONS: Mortality is higher in Tx recipients than in the general population. Poor outcome seems to be related to a delay in the beginning of treatment.