Moore, Shona 
ORCID: 0000-0001-8610-2806, Kronsteiner, Barbara, Longet, Stephanie, Adele, Sandra, Deeks, Alexandra, Liu, Chang, Dejnirattisai, Wanwisa, Silva Reyes, Laura, Meardon, Naomi, Faustini, Sian et al (show 54 more authors)
(2023)
Evolution of Long-Term Hybrid Immunity in Healthcare Workers after Different Covid-19 Vaccination Regimens: A Longitudinal Observational Cohort Study.
Med, 4 (3).
191-215.e9.
ISSN 2666-6359
Abstract
BACKGROUND: Both infection and vaccination, alone or in combination, generate antibody and T cell responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the maintenance of such responses-and hence protection from disease-requires careful characterization. In a large prospective study of UK healthcare workers (HCWs) (Protective Immunity from T Cells in Healthcare Workers [PITCH], within the larger SARS-CoV-2 Immunity and Reinfection Evaluation [SIREN] study), we previously observed that prior infection strongly affected subsequent cellular and humoral immunity induced after long and short dosing intervals of BNT162b2 (Pfizer/BioNTech) vaccination. METHODS: Here, we report longer follow-up of 684 HCWs in this cohort over 6-9 months following two doses of BNT162b2 or AZD1222 (Oxford/AstraZeneca) vaccination and up to 6 months following a subsequent mRNA booster vaccination. FINDINGS: We make three observations: first, the dynamics of humoral and cellular responses differ; binding and neutralizing antibodies declined, whereas T and memory B cell responses were maintained after the second vaccine dose. Second, vaccine boosting restored immunoglobulin (Ig) G levels; broadened neutralizing activity against variants of concern, including Omicron BA.1, BA.2, and BA.5; and boosted T cell responses above the 6-month level after dose 2. Third, prior infection maintained its impact driving larger and broader T cell responses compared with never-infected people, a feature maintained until 6 months after the third dose. CONCLUSIONS: Broadly cross-reactive T cell responses are well maintained over time-especially in those with combined vaccine and infection-induced immunity ("hybrid" immunity)-and may contribute to continued protection against severe disease. FUNDING: Department for Health and Social Care, Medical Research Council.
| Item Type: | Article |
|---|---|
| Additional Information: | Source info: CP-COMMUNITY-D-22-00900 |
| Uncontrolled Keywords: | antibody, COVID vaccine, COVID-19, immunity, SARS-CoV-2, T cells |
| Divisions: | Faculty of Health and Life Sciences Faculty of Health and Life Sciences > Institute of Life Courses and Medical Sciences Faculty of Health and Life Sciences > Institute of Infection, Veterinary and Ecological Sciences |
| Depositing User: | Symplectic Admin |
| Date Deposited: | 24 Jul 2023 11:47 |
| Last Modified: | 13 May 2025 18:18 |
| DOI: | 10.1016/j.medj.2023.02.004 |
| Open Access URL: | https://www.cell.com/med/fulltext/S2666-6340(23)00... |
| URI: | https://livrepository.liverpool.ac.uk/id/eprint/3171843 |
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