Adaptive immune responses to two-dose COVID-19 vaccine series in healthy Canadian adults ≥ 50 years: a prospective, observational cohort study.

Karen Simmons, Agatha N Jassem, Mel Krajden, Danuta M Skowronski, Muhammad Morshed, James E A Zlosnik, Inna Sekirov, Theodore Steiner, Laura Cook, Sofia R Bartlett, Ana Citlali Márquez, Bing Cai, Hennady P Shulha, Hannah M Baer, Jean J Zheng, Mandy Lo, Chad Poloni, Brynn McMillan, Gabrielle N Gaultier, Manish Sadarangani, Megan K Levings

Journal: Scientific reports 2024;14(1):8926

PMID: 38637558

Free Full Text on Nature Publishing Group View on PubMed

Abstract

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.

Address: Department of Pediatrics, University of British Columbia, 950 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada. [email protected].; Vaccine Evaluation Center, British Columbia Children's Hospital Research Institute, Vancouver, BC, Canada. [email protected].; Vaccine Evaluation Center, British Columbia Children's Hospital Research Institute, Vancouver, BC, Canada.; Experimental Medicine Program, University of British Columbia, Vancouver, BC, Canada.; Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada.; British Columbia Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada.; Department of Pediatrics, University of British Columbia, 950 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada.; Vaccine Evaluation Center, British Columbia Children's Hospital Research Institute, Vancouver, BC, Canada.; Vaccine Evaluation Center, British Columbia Children's Hospital Research Institute, Vancouver, BC, Canada.; Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada.; Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada.; British Columbia Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada.; Institute of Infection, Inflammation & Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.; British Columbia Centre for Disease Control, Vancouver, BC, Canada.; British Columbia Centre for Disease Control, Vancouver, BC, Canada.; School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada.; British Columbia Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada.; Department of Medicine, University of British Columbia, Vancouver, BC, Canada.; Department of Microbiology & Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia.; British Columbia Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada.; Department of Surgery, University of British Columbia, Vancouver, BC, Canada.; School of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada.; British Columbia Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada.; Department of Medicine, University of British Columbia, Vancouver, BC, Canada.; British Columbia Centre for Disease Control, Vancouver, BC, Canada.; Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.

DOI: 10.1038/s41598-024-59535-0

Link outs

Free resources

Full Text Sources:

Medical:

https://medlineplus.gov/covid19coronavirusdisease2...

Miscellaneous:

https://assays.cancer.gov/CPTAC-169

Research Materials:

https://antibodies.cancer.gov/detail/CPTC-CD8A-1

MeSH Terms: Adult, Humans, Middle Aged, Aged, COVID-19 Vaccines, Angiotensin-Converting Enzyme 2, BNT162 Vaccine, Prospective Studies, COVID-19, Canada, Antibodies, ChAdOx1 nCoV-19, RNA, Messenger, Antibodies, Viral, Vaccination