Vaccine effectiveness against the SARS-CoV-2 B.1.1.529 Omicron variant in solid organ and islet transplant recipients in England: a national retrospective cohort study

Abstract

Background
The effectiveness of vaccines against the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) B.1.1.529 Omicron variant in immunosuppressed solid organ and islet transplant (SOT) recipients is unclear.
Methods
National registries in England were linked to identify SARS-CoV-2 positive tests, noninjury hospitalisation within 14 days, and deaths within 28 days between 7 December 2020 and 31 March 2022 in adult SOT recipients. Incidence rate ratios (IRRs) for infection, and hospitalisation or death, were adjusted for recipient demographics and calendar month for the Omicron-dominant period (20 December 2021 to 31 March 2022). Mortality risk following SARS-CoV-2 infection was adjusted for recipient
demographics and dominant variant using a Cox proportional-hazards model for the entire time period.
Results
During the Omicron-dominant period, infection IRRs (95% confidence intervals) were higher in those receiving two, three and four vaccine doses compared to unvaccinated patients (1·25 (1·08-1·45), 1·46 (1·28-1·67), and 1·79 (1·54-2·06), respectively). However, hospitalisation or death IRRs during this period were lower in those receiving three or four vaccine doses compared to unvaccinated patients (0·62 (0·45-0·86) and
0·39 (0·26-0·58), respectively). Risk-adjusted analyses for deaths after SARS-CoV-2 infection between 7 December 2020 to 31 March 2022 found hazard ratios (95% confidence intervals) of 0·67 (0·46-0·98), 0·46 (0·30-0·69), 0·18 (0·09-0·35) for those with two, three, and four vaccine doses, respectively, when compared to the unvaccinated group.
Conclusions
In immunosuppressed SOT recipients, vaccination is associated with incremental, dose-dependent protection against hospitalisation or death after SARS-CoV-2 infection, including against the Omicron variant.

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This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0/

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DOI

https://doi.org/10.1097/TP.0000000000004535

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https://www.research.ed.ac.uk/en/publications/f1a26d79-661d-4cdf-952e-aaa7945fe09f