SARS-CoV-2-reactive antibody waning, booster effect and breakthrough SARS-CoV-2 infection in hematopoietic stem cell transplant and cell therapy recipients at one year after vaccination - Report - MDSpire
Advertisement
SARS-CoV-2-reactive antibody waning, booster effect and breakthrough SARS-CoV-2 infection in hematopoietic stem cell transplant and cell therapy recipients at one year after vaccination
Decline of SARS-CoV-2 Antibodies and Impact of Boosters in Hematopoietic Cell Therapy Recipients
Overview
This study evaluated the kinetics of SARS-CoV-2 spike-reactive antibody titers and the incidence of breakthrough COVID-19 infections over one year in recipients of autologous and allogeneic hematopoietic stem cell transplantation and CAR-T cell therapy. It demonstrated waning antibody levels post-vaccination, the beneficial effect of booster doses in increasing antibody titers, and characterized breakthrough infection rates and severity in this vulnerable population.
Background
Recipients of hematopoietic stem cell transplantation (HSCT) and CAR-T cell therapy are at high risk for severe COVID-19, with mortality exceeding 18% during early pandemic waves. Although mRNA vaccines elicit SARS-CoV-2 spike-reactive antibodies and reduce severe disease, antibody titers decline over time, raising concerns about sustained protection. The emergence of variants like Omicron further challenges vaccine efficacy, especially in immunocompromised patients who have lower initial antibody responses. Booster doses have been recommended, but data on their impact on antibody kinetics and breakthrough infections in this population remain limited.
Data Highlights
Time Point
Antibody Measurement
Patient Group
Findings
3-6 weeks post-vaccination
SARS-CoV-2-S-RA titers
ASCT, allo-HSCT, CAR-T recipients
Initial antibody response measured; poor responders defined as <250 BAU/mL
3 months
Antibody titers
Same groups
Decline in antibody levels observed
6 months
Antibody titers
Same groups
Further decline in titers noted
Post-booster dose
Antibody titers
Same groups
Significant increase in antibody titers compared to pre-booster levels
Up to 12 months
Breakthrough infection incidence
All groups
Breakthrough infections documented with severity and risk factors analyzed
Key Findings
SARS-CoV-2 spike-reactive antibody titers decline progressively over 6 months following full vaccination in HSCT and CAR-T recipients.
Patients with prior COVID-19 infection before vaccination show higher and more sustained antibody levels.
Breakthrough SARS-CoV-2 infections occur despite vaccination, with incidence and severity influenced by antibody titers and patient characteristics.
Omicron variant predominance correlates with increased breakthrough infections, highlighting variant impact on vaccine efficacy.
Poor responders (antibody titers <250 BAU/mL) are at higher risk for breakthrough infection and severe disease.
Clinical Implications
Monitoring SARS-CoV-2 antibody titers in HSCT and CAR-T recipients can help identify patients at risk of waning immunity and breakthrough infection. Booster vaccinations are effective in enhancing antibody responses and should be prioritized in this immunocompromised population. Awareness of variant circulation is important for risk stratification and guiding prophylactic strategies.
Conclusion
In recipients of hematopoietic stem cell transplantation and CAR-T therapy, SARS-CoV-2 antibody levels wane over time but can be effectively boosted, reducing the risk of breakthrough infections. Ongoing surveillance and tailored vaccination strategies are essential to protect these vulnerable patients.
References
GETH-TC Registry Study 2022 -- Decline of SARS-CoV-2 Antibodies and Impact of Boosters
by José Luis Piñana, Rodrigo Martino, Lourdes Vazquez, Lucia López-Corral, Ariadna Pérez, Pedro Chorão, Alejandro Avendaño-Pita, María-Jesús Pascual, Andrés Sánchez-Salinas, Gabriela Sanz-Linares, María T. Olave, Ignacio Arroyo, Mar Tormo, Lucia Villalon, Venancio Conesa-Garcia, Beatriz Gago, María-José Terol, Marta Villalba, Valentín Garcia-Gutierrez, Almudena Cabero, José Ángel Hernández-Rivas, Elena Ferrer, Irene García-Cadenas, Anabel Teruel, David Navarro, Ángel Cedillo, Anna Sureda, Carlos Solano
