Severe SARS-Cov2 pneumonia in vaccinated patients: a multicenter cohort study

Vaccination reduces risk of infection, hospitalization, and death due to SARS-Cov2. Vaccinated patients may however experience severe SARS-Cov2 disease. The objective was to describe clinical features of vaccinated patients requiring intensive care unit (ICU) admission due to SARS-Cov2 infection and compare them to a published cohort of unvaccinated patients. We performed a multicenter cohort study of patients with severe SARS-Cov2 disease admitted to 15 ICUs in France between January and September 2021. 100 consecutive vaccinated patients (68 (68%) men, median age 64 [57-71]) were included. Immunosuppression was reported in 38 (38%) patients. Among available serologies at ICU admission, 64% exhibited an optimal antibody level. Median SOFA score at ICU admission was 4 [4-6.3] and median PaO2/FiO2 ratio was 84 [69-128] mmHg. A total of 79 (79%) and 18 (18%) patients received high flow nasal oxygen and non-invasive mechanical ventilation, respectively. Invasive mechanical ventilation (IMV) was initiated in 48 (48%) with a median duration of 11 [5-19] days. During a median ICU length-of-stay of 8 [4-20] days, 31 (31%) patients died. Age (OR per 5-years increment 1.38 CI95% [1.02-1.85]p = 0.035), and SOFA at ICU admission (OR 1.40 CI95% [1.14-1.72] per point, p = 0.002) were independently associated with mortality. When compared to a cohort of 1316 unvaccinated patients (72% men, median age 63 [53-71]), vaccinated patients exhibited less frequently diabetes (16 [16%] vs. 351 [27%]p = 0.029) but were more frequently immunosuppressed (38 [38%] vs. 109 (8.3%), p < 0.0001), had more frequently chronic kidney disease (24 [24%] vs. 89 (6.8%), p < 0.0001), chronic heart failure (16 [16%] vs. 58 [4.4%]p < 0.0001), and chronic liver disease (3 [3%] vs. 8 [0.6%]p = 0.037) compared to unvaccinated patients. Despite similar severity, vaccinated patients required less frequently IMV at ICU day 1 and during ICU stay (23 [23%] vs. 785 [59.7%]p < 0.0001, and 48 [48%] vs. 930 [70.7%]p < 0.0001, respectively). There was no difference concerning ICU mortality (31 [31%] vs. 379 [28.8%]p = 0.64). Severe SARS-Cov2 infection after vaccination occurs mainly in patients with immunosuppression, chronic kidney, heart or liver failure. Age and disease severity are independently associated with mortality.