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).
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).
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
OTHER
Masking
NONE
Enrollment
880
diagnostic serology of severe acute respiratory syndrome-CoV-2 infection performed during the inclusion visit Regarding follow-up visits, only seropositive patients will be called for sampling, for serological follow-up at 3 months then 6 months.
The positivity of total anti-SARS-CoV-2 blood Ig will be determined by the presence of anti-spike protein Ig G and / or anti-nucleocapsid Ig G (post-infectious COVID-19 humoral immunity).
To determine the seroprevalence of SARS-CoV-2 after the 4th epidemic wave in unvaccinated sickle cell patients (children and adults), living in an area with high viral circulation of SARS-CoV-2 and high risk of viral transmission, in Ile-De-France.
Time frame: 9 months
The positivity anti-SARS-CoV-2 serology and anti-spike antibody titre from M0 to M6.
Compare the seroprevalence and decrease in antibodies (initial M0 titre and duration of persistence at M3-M6) in unvaccinated patients with a history of COVID-19 infection between the group of children with sickle cell disease, the group of children non-sickle cell control patients and the group of adults with sickle cell disease.
Time frame: 9 months
Negativity of anti-SARS-CoV-2 serology at M3 and M6.
Investigation of factors associated with a faster loss of anti-SARS-CoV-2 blood antibodies (age, sex, genotype, splenectomy, transplants, treatment with hydroxyurea) in unvaccinated sickle cell patients with a history of COVID-19 infection.
Time frame: 3 and 6 months
COVID-19 infection (nasopharyngeal RT-PCR Reverse transcription-polymerase chain reaction positivity and/or COVID-19 anti-SARS-CoV-2 serology).
Assessing factors associated with the risk of COVID-19 infection (epidemiological, environmental and sickle cell disease related) in sickle cell patients.
Time frame: 9 months
Intensive care unit admission for COVID-19.
Assessing factors associated with a severe form of COVID-19 infection among sickle cell patients.
Time frame: 9 months
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Proportion of patients vaccinated among the patients interviewed and included in the study.
Determine the vaccination coverage rate of the sickle cell population (according to age groups) over a period of 3 months, after the 4th epidemic wave of 2021.
Time frame: 9 months
Occurrence of post-vaccine side effects (fever, pain, vaso-occlusive crisis, myocarditis, others)
List the occurrence of declared side effects.
Time frame: 9 months
Proportion of COVID-19 infection occurring in vaccinated patients.
Determine the incidence rate of COVID-19 infection in vaccinated patients (vaccine failure rate)
Time frame: 9 months