COVID-19 mRNA Vaccination Responses in Individuals With Sickle Cell Disease: ASH RC Sickle Cell Research Network Study.

Children and adults with sickle cell disease (SCD) have increases in morbidity and mortality with COVID-19 infections. The ASH Research Collaborative Sickle Cell Disease Research Network performed a prospective COVID-19 vaccine study to assess antibody responses and analyze whether mRNA vaccination precipitated any adverse effects unique to individuals with SCD. Forty-one participants received two doses of the Pfizer-BioNTech vaccine and provided baseline blood samples prior to vaccination and 2 months after the initial vaccination for analysis of IgG reactivity against the receptor binding domain (RBD) of the SARS-CoV-2 spike protein. Six month IgG reactivity against the viral RBD was also available in 37 patients. Post-vaccination reactogenicity was common and similar to the general population. There were no fevers that required inpatient admission. Vaso-occlusive pain within 2-3 days of 1st or 2nd vaccination was reported by 5 (12%) participants including 4 (10%) who sought medical care. Twenty-seven participants (66%) were seropositive at baseline, and all 14 (34%) initially seronegative participants converted to seropositive post vaccination. Overall, mRNA vaccination had a good risk benefit-profile in individuals with sickle cell disease.This mRNA vaccine study also marks the first evaluation of vaccine safety and antibody response in very young children with sickle cell disease. NCT05139992.