TY - JOUR
AU - Gaultier, Gabrielle N
AU - McMillan, Brynn
AU - Poloni, Chad
AU - Lo, Mandy
AU - Cai, Bing
AU - Zheng, Jean J.
AU - Baer, Hannah M.
AU - Shulha, Hennady P.
AU - Simmons, Karen
AU - Márquez, Ana Citlali
AU - Bartlett, Sofia R.
AU - Cook, Laura
AU - Levings, Megan K.
AU - Steiner, Theodore
AU - Sekirov, Inna
AU - Zlosnik, James E.A.
AU - Morshed, Muhammad
AU - Skowronski, Danuta M.
AU - Krajden, Mel
AU - Jassem, Agatha N.
AU - Sadarangani, Manish
PY - 2024
DA - April
TI - Adaptive immune responses to two-dose COVID-19 vaccine series in healthy Canadian adults ≥ 50 years: a prospective, observational cohort study
JO - Scientific Reports
VL - 14
DO - https://doi.org/10.1038/s41598-024-59535-0
AB - To evaluate immune responses to COVID-19 vaccines in adults aged 50 years and older, spike protein (S)-specific antibody concentration, avidity, and function (via angiotensin-converting enzyme 2 (ACE2) inhibition surrogate neutralization and antibody dependent cellular phagocytosis (ADCP)), as well as S-specific T cells were quantified via activation induced marker (AIM) assay in response to two-dose series. Eighty-four adults were vaccinated with either: mRNA/mRNA (mRNA-1273 and/or BNT162b2); ChAdOx1-S/mRNA; or ChAdOx1-S/ChAdOx1-S. Anti-S IgG concentrations, ADCP scores and ACE2 inhibiting antibody concentrations were highest at one-month post-second dose and declined by four-months post-second dose for all groups. mRNA/mRNA and ChAdOx1-S/mRNA schedules had significantly higher antibody responses than ChAdOx1-S/ChAdOx1-S. CD8 T-cell responses one-month post-second dose were associated with increased ACE2 surrogate neutralization. Antibody avidity (total relative avidity index) did not change between one-month and four-months post-second dose and did not significantly differ between groups by four-months post-second dose. In determining COVID-19 correlates of protection, a measure that considers both antibody concentration and avidity should be considered.
PB - Springer Nature
UR - https://eprints.gla.ac.uk/325429/
KW - Coronavirus (COVID-19)
KW - Immunisation and screening
KW - Older people
ER