New research presented by the ASH Research Collaborative™ (ASH RC)* during the 65th Annual Meeting of the American Society of Hematology, revealed that individuals living with sickle cell disease (SCD) exhibited similar side effects and levels of protection against COVID-19 when compared to the general population after receiving a COVID-19 mRNA vaccine.
This study represents the largest prospective investigation to date on COVID-19 vaccine efficacy among individuals living with sickle cell disease and the first to evaluate vaccine safety and antibody response in young children living with sickle cell disease.
“We performed this study because of previous evidence suggesting that individuals with sickle cell disease do not mount as robust or sustained of an immune response following vaccinations as the general population. There was also concern expressed by patients that the newer mRNA vaccine technology might induce pain crises, a unique complication that affects those with sickle cell disease. We wanted to understand how we can best protect those living with sickle cell disease from severe illness from COVID-19 infection,” explained Charles Abrams, MD, a hematologist at Penn Medicine and Chair of the SCD Clinical Trials Network Oversight Committee, and a study’s senior author.
“Reassuringly, we found that our study participants had similar immune responses as the general population and largely did not experience major complications as a consequence of receiving a mRNA vaccine,” Abrams said.
The most common inherited red blood cell disorder
Sickle cell disease is the most common inherited red blood cell disorder in the United States, affecting an estimated 100,000 people. According to the Centers for Disease Control and Prevention (CDC), sickle cell disease affects one out of every 365 Black or African American births and one out of every 16,300 Hispanic American births.
In sickle cell disease, red blood cells become hard and sticky and look like a C-shaped farm tool called a ‘sickle.’ The condition can cause significant disease-related morbidity, severe and debilitating pain, joint and multiorgan damage, chronic anemia, and stroke. However, patients diagnosed with sickle cell disease can live full lives and enjoy most of the activities that other people do. 
Some prior studies highlighted significantly worse outcomes in children and adults living with sickle cell disease who contracted COVID-19 in comparison to the general public, making those living with sickle cell disease a high-risk population and a priority target for vaccination efforts.
The ASH RC SCD CTN investigators enrolled 59 previously unvaccinated participants ranging in age from 1 to 53 years, 47 of whom received at least one dose of the monovalent vaccine.
Forty-one participants who received two vaccination doses contributed baseline pre-vaccination and two-month post-vaccination blood samples, and 37 of the participants also provided a 6-month post-vaccination sample.
Researchers assessed the reactivity of IgG antibodies – proteins produced by the body in response to infection – against the receptor binding domain (where the antibody binds to combat the virus) of the SARS-CoV-2 spike protein. Side effects were assessed by telephone visits with the participants 2-3 days after each vaccine dose.
This study demonstrated that individuals with sickle cell disease who were vaccinated with a COVID mRNA vaccine generated anti-SARS-CoV-2 antibodies similar to the general population. Also, similar to most people, their antibody titers decreased over time but were still present six months after vaccination.
This prospective study was conducted across eight clinical sites within the ASH RC Sickle Cell Disease Clinical Trials Network (SCD Network), including Johns Hopkins University School of Medicine; Prisma Health Children’s Hospital; Duke University Medical Center, UT Southwestern Medical Center; Medical College of Wisconsin; University of California, San Fransisco General Hospital; Children’s National Hospital; and Montefiore Medical Center.
“In establishing the Clinical Trials Network, ASH has demonstrated the Society’s continued commitment to improving the lives of individuals living with sickle cell disease,” Abrams noted.
“This study, sponsored by ASH, is the first to run entirely within the CTN. These results are crucial to the management of sickle cell disease and help hematologists better understand the implications of future mRNA vaccines,” he concluded.
Note: * Patients living with hematologic conditions generally require more evidence-based options for managing their health and improving their health-related Quality of Life (hrQoL). The ASH Research Collaborative helps to accelerate change by making it easier to conduct research, including increasing access to high-quality clinical data and making it easier for patients to participate in clinical studies. Current initiatives primarily focus on clinical research in multiple myeloma (MM) and sickle cell disease (SCD) clinical research.
ASH Research Collaborative Data Hub – ClinicalTrials.gov Identifier: NCT05775224
 Anderson AR, Strouse JJ, Manwani D, Brandow AM, Vichinsky EP, Leavey P, Field J, Hensley S, Mortier N, Lanzkron SM, Neuberg DS, Abrams CS. (2525) COVID mRNA Vaccination Responses in Individuals with Sickle Cell Disease: An ASH Research Collaborative Clinical Trial Network Study. Presented during the 2023 annual meeting of the American Society of Hematology.Sunday, December 10, 2023, 6:00 PM-8:00 PM [Abstract]
 Onimoe G, Rotz S. Sickle cell disease: A primary care update. Cleve Clin J Med. 2020 Jan;87(1):19-27. doi: 10.3949/ccjm.87a.18051. Epub 2020 Jan 2. PMID: 31990651.