A study was conducted on a cohort of 48 patients, aged 20 to 80, who developed a severe to critical form following an infection with the Delta variant, despite a complete vaccination schedule with an mRNA vaccine. As Inserm states in a press release, “The idea was thus to rule out severe forms that may have developed following a failure of vaccination, in order to isolate and identify other factors. For various reasons (HIV infection, presence of lymphoma, taking immunosuppressive treatments…), six patients had a defective vaccine response and were therefore excluded from the study”.
The results were published in the journal Science Immunology. Among these 42 people vaccinated against Covid and having developed a severe form, 24% present an immunological deficit, that is to say a dysfunction of the immune system. Specifically, these people had “antibodies that were able to neutralize type 1 interferons”, these 17 proteins produced by cells to block virus replication.