Sickle cell disease is a very widespread genetic disease affecting 300,000 births worldwide, with a prevalence of one affected child for 1736 births in France, the most common genetic disease in France. France is the European country with the highest prevalence of the disease while Ile-de-France is the region with the highest prevalence of sickle cell disease and COVID-19. The medical management of sickle cell patients raises many challenges related to the complexity of their disease and the comorbidities that may be associated with their conditions (arterial hypertension, pulmonary arterial hypertension, nephropathy and renal failure, cerebral vasculopathy).Our seroprevalence study will focus on the sickle cell population living in an area with high circulation of severe acute respiratory syndrome-CoV-2; it will start after the 4th epidemic wave of COVID-19 during the vaccination campaigns, in order to collect on the one hand seroprevalence data (proportion of unvaccinated seropositive sickle cell patients) and persistence of humoral immunity (quantitative) after infection in unvaccinated subjects and on the other hand, to assess the vaccination coverage in this specific population (adults and adolescents) as well as its impact (occurrence of vaccine failures).
The objective of this study is to determine the seroprevalence of severe acute respiratory syndrome-CoV-2 in unvaccinated sickle cell patients living in an area with high viral circulation and at risk of high viral transmission, after the 4th epidemic wave of COVID-19 in Ile-de -France, over a period of 3 months (for example, last quarter of 2021).