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BMJ Open
. 2023 Oct 31;13(10):e077714.
doi: 10.1136/bmjopen-2023-077714.
Results of the Stop the Spread Ottawa (SSO) cohort study: a Canadian urban-based prospective evaluation of antibody responses and neutralisation efficiency to SARS-CoV-2 infection and vaccination
Alexa Keeshan 1 2 , Yannick Galipeau 3 , Aliisa Heiskanen 1 2 , Erin Collins 2 , Pauline S McCluskie 4 , Corey Arnold 4 , Raphael Saginur 5 , Ronald Booth 6 , Julian Little 2 , Michaeline McGuinty 7 , C Arianne Buchan 1 7 8 , Anglea Crawley 8 9 10 , Marc-Andre Langlois 10 11 , Curtis Cooper 12 8 10 13
Affiliations
PMID: 37907304 DOI: 10.1136/bmjopen-2023-077714
Abstract
Background: Predictors of COVID-19 vaccine immunogenicity and the influence of prior severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection require elucidation.
Methods: Stop the Spread Ottawa is a prospective cohort of individuals at-risk for or who have been infected with SARS-CoV-2, initially enrolled for 10 months beginning October 2020. This cohort was enriched for public-facing workers. This analysis focuses on safety and immunogenicity of the initial two doses of COVID-19 vaccine.
Results: Post-vaccination data with blood specimens were available for 930 participants. 22.8% were SARS-CoV2 infected prior to the first vaccine dose. Cohort characteristics include: median age 44 (IQR: 22-56), 66.6% women, 89.0% white, 83.2% employed. 38.1% reported two or more comorbidities and 30.8% reported immune compromising condition(s). Over 95% had detectable IgG levels against the spike and receptor binding domain (RBD) 3 months post second vaccine dose. By multivariable analysis, increasing age and high-level immune compromise predicted diminishing IgG spike and RBD titres at month 3 post second dose. IgG spike and RBD titres were higher immediately post vaccination in those with SARS-CoV-2 infection prior to first vaccination and spike titres were higher at 6 months in those with wider time intervals between dose 1 and 2. IgG spike and RBD titres and neutralisation were generally similar by sex, weight and whether receiving homogeneous or heterogeneous combinations of vaccines. Common symptoms post dose 1 vaccine included fatigue (64.7%), injection site pain (47.5%), headache (27.2%), fever/chills (26.2%) and body aches (25.3%). These symptoms were similar with subsequent doses.
Conclusion: The initial two COVID-19 vaccine doses are safe, well-tolerated and highly immunogenic across a broad spectrum of vaccine recipients including those working in public facing environments.
Keywords: COVID-19; immunology; safety.