TY - JOUR
T1 - Antibody concentration and function following SARS-CoV-2 vaccination decrease with age in adults and children with Down syndrome
AU - Streng, Bianca M.M.
AU - Hensen, Lobke C.M.
AU - Delemarre, Eveline M.
AU - Binnendijk, Rob S.
AU - Smits, Gaby
AU - den Hartog, Gerco
AU - van der Klis, Fiona R.
AU - de Vries, Esther
AU - Burger, Judith A.
AU - van Gils, Marit J.
AU - Coppus, Antonia M.W.
AU - Weijerman, Michel E.
AU - Lamberts, Regina
AU - de Graaf, Gert
AU - Bont, Louis J.
AU - Wildenbeest, Joanne G.
N1 - Publisher Copyright:
© 2025
PY - 2025/12/24
Y1 - 2025/12/24
N2 - Introduction: Individuals with Down syndrome (DS) have an altered immune system, highlighted by increased illness and mortality during the SARS-CoV-2 pandemic. We previously showed decreased antibody concentrations after primary SARS-CoV-2 vaccination in DS adults. We prospectively studied antibody responses and functionality after SARS-CoV-2 primary and booster vaccination in adults and children with DS. Methods: We measured antibody concentrations for anti-S and anti-RBD following primary and booster vaccination and virus neutralizing titers (ID50) after primary vaccination. Adults with DS (N = 215) or healthy controls (HC, N = 93), received 2 primary doses of mRNA-based (BNT162b2/mRNA-1273) or vector-based (ChAdOx1) vaccines. Children received mRNA-based vaccines. Booster vaccination was mRNA-based. Results: A rise in antibody concentrations was seen in all participants, but DS had lower anti-S antibody concentrations than HC after primary mRNA (1286 BAU/mL, vs. 2355 BAU/mL, p < 0.001) or vector (361 BAU/mL, vs. 592 BAU/mL p < 0.01) vaccination. Only in DS, anti-S concentrations declined with age (correlation-coefficient − 0.61, p < 0.001). Amongst children with DS, teenagers (12–17 years) showed highest anti-S concentrations (3286 BAU/mL), children (<12 years) had lower concentrations compared with teenagers (1424 BAU/mL, p < 0.01). Booster vaccination increased anti-S concentrations in DS and HC at all ages. However, lower concentrations in DS compared with HC remained, regardless of primary vaccine type (mRNA/vector). Anti-RBD antibodies showed similar results to anti-S. Serum neutralization was lower in DS adults compared with HC for mRNA (ID50 120 vs. ID50 336, p < 0.001) and vector (ID50 51 vs. ID50 95 p < 0.01) vaccination. Conclusion: This is the first vaccine immunology study in DS including both children and adults. Although all participants showed a rise in antibody concentrations, decreased antibody concentrations and serum neutralization after primary and booster SARS-CoV-2 vaccination were seen in individuals with DS compared with HC. Vaccine response defects in DS were age dependent, increasing with age. Teenagers with DS had the highest antibody concentrations while children <12 years had significantly lower concentrations. Our findings highlight the need for a tailored, age-specific immunization strategy in DS.
AB - Introduction: Individuals with Down syndrome (DS) have an altered immune system, highlighted by increased illness and mortality during the SARS-CoV-2 pandemic. We previously showed decreased antibody concentrations after primary SARS-CoV-2 vaccination in DS adults. We prospectively studied antibody responses and functionality after SARS-CoV-2 primary and booster vaccination in adults and children with DS. Methods: We measured antibody concentrations for anti-S and anti-RBD following primary and booster vaccination and virus neutralizing titers (ID50) after primary vaccination. Adults with DS (N = 215) or healthy controls (HC, N = 93), received 2 primary doses of mRNA-based (BNT162b2/mRNA-1273) or vector-based (ChAdOx1) vaccines. Children received mRNA-based vaccines. Booster vaccination was mRNA-based. Results: A rise in antibody concentrations was seen in all participants, but DS had lower anti-S antibody concentrations than HC after primary mRNA (1286 BAU/mL, vs. 2355 BAU/mL, p < 0.001) or vector (361 BAU/mL, vs. 592 BAU/mL p < 0.01) vaccination. Only in DS, anti-S concentrations declined with age (correlation-coefficient − 0.61, p < 0.001). Amongst children with DS, teenagers (12–17 years) showed highest anti-S concentrations (3286 BAU/mL), children (<12 years) had lower concentrations compared with teenagers (1424 BAU/mL, p < 0.01). Booster vaccination increased anti-S concentrations in DS and HC at all ages. However, lower concentrations in DS compared with HC remained, regardless of primary vaccine type (mRNA/vector). Anti-RBD antibodies showed similar results to anti-S. Serum neutralization was lower in DS adults compared with HC for mRNA (ID50 120 vs. ID50 336, p < 0.001) and vector (ID50 51 vs. ID50 95 p < 0.01) vaccination. Conclusion: This is the first vaccine immunology study in DS including both children and adults. Although all participants showed a rise in antibody concentrations, decreased antibody concentrations and serum neutralization after primary and booster SARS-CoV-2 vaccination were seen in individuals with DS compared with HC. Vaccine response defects in DS were age dependent, increasing with age. Teenagers with DS had the highest antibody concentrations while children <12 years had significantly lower concentrations. Our findings highlight the need for a tailored, age-specific immunization strategy in DS.
KW - Antibody
KW - Down syndrome
KW - Immune response
KW - SARS-CoV-2 vaccination
UR - https://www.scopus.com/pages/publications/105025788427
U2 - 10.1016/j.vaccine.2025.128079
DO - 10.1016/j.vaccine.2025.128079
M3 - Article
C2 - 41447779
AN - SCOPUS:105025788427
SN - 0264-410X
VL - 73
JO - Vaccine
JF - Vaccine
M1 - 128079
ER -