tetano
Editor, Senior Moderator
Expert Rev Vaccines
. 2026 Dec 31;25(1):2708184.
doi: 10.1080/14760584.2026.2708184. Epub 2026 Jul 26.
Adapted XBB.1.5 vaccine effectiveness against severe COVID-19 outcomes among immunocompromised persons in 2023-24 in six European countries: a VEBIS-EHR network study
Alexandre Blake[SUP] 1 [/SUP], James Humphreys[SUP] 1 [/SUP], Kate Olson[SUP] 2 [/SUP], Toon Braeye[SUP] 3 [/SUP], Izaak Van Evercooren[SUP] 3 [/SUP], Christian Holm Hansen[SUP] 4 [/SUP], Ida Rask Moustsen-Helms[SUP] 4 [/SUP], Massimo Fabiani[SUP] 5 [/SUP], Alberto Mateo-Urdiales[SUP] 5 [/SUP], Jesús Castilla[SUP] 6 7 [/SUP], Iván Martínez-Baz[SUP] 6 7 [/SUP], Ausenda Machado[SUP] 8 [/SUP], Andre Brito[SUP] 8 [/SUP], Rickard Ljung[SUP] 9 10 [/SUP], Nicklas Pihlström[SUP] 9 10 [/SUP], Yohann Mansiaux[SUP] 1 [/SUP], Nathalie Nicolay[SUP] 2 [/SUP], Susana Monge[SUP] 11 12 [/SUP], Baltazar Nunes[SUP] 1 [/SUP]; VEBIS-EHR working group
Affiliations
Background: We estimated the XBB.1.5 vaccine effectiveness (VE) against COVID-19 hospitalization and death in Belgium, Denmark, Italy, Portugal, Spain (Navarre), and Sweden following the 2023-24 fall vaccination campaign among immunocompromised persons (ICPs).
Research design and methods: We conducted a multi-country retrospective cohort study using electronic health records. Study sites identified ICPs aged ≥18 years through a common set of immunocompromising conditions and follow-up started the first day of the 2023 vaccination campaign until 12 months later. VE was calculated by time since vaccination (14-59, 60-119, 120-179, 180-365 days after vaccination) for ICPs by pooling study site level confounder adjusted hazard ratios (aHR) of vaccination, estimated with Cox proportional hazards regression models, using a random effect meta-analysis with VE = 100 × (1-pooled aHR).
Results: The XBB.1.5 VE was 52% (95% confidence interval (CI): 41 to 60) and 75% (95%CI: 60 to 84) against hospitalization and death, respectively, 14-59 days after vaccination, and VE decreased with time since vaccination with no remaining protection at 180-365 days after vaccination.
Conclusion: Adapted XBB.1.5 vaccine provided moderate protection within 120 days after vaccination against severe COVID-19 outcomes among ICPs aged ≥18 years during a period with BA.2.86/JN.1 replacing the XBB.1.5 variant.
Keywords: COVID-19; immunocompromised; vaccine effectiveness; viral sublineages; waning protection.
. 2026 Dec 31;25(1):2708184.
doi: 10.1080/14760584.2026.2708184. Epub 2026 Jul 26.
Adapted XBB.1.5 vaccine effectiveness against severe COVID-19 outcomes among immunocompromised persons in 2023-24 in six European countries: a VEBIS-EHR network study
Alexandre Blake[SUP] 1 [/SUP], James Humphreys[SUP] 1 [/SUP], Kate Olson[SUP] 2 [/SUP], Toon Braeye[SUP] 3 [/SUP], Izaak Van Evercooren[SUP] 3 [/SUP], Christian Holm Hansen[SUP] 4 [/SUP], Ida Rask Moustsen-Helms[SUP] 4 [/SUP], Massimo Fabiani[SUP] 5 [/SUP], Alberto Mateo-Urdiales[SUP] 5 [/SUP], Jesús Castilla[SUP] 6 7 [/SUP], Iván Martínez-Baz[SUP] 6 7 [/SUP], Ausenda Machado[SUP] 8 [/SUP], Andre Brito[SUP] 8 [/SUP], Rickard Ljung[SUP] 9 10 [/SUP], Nicklas Pihlström[SUP] 9 10 [/SUP], Yohann Mansiaux[SUP] 1 [/SUP], Nathalie Nicolay[SUP] 2 [/SUP], Susana Monge[SUP] 11 12 [/SUP], Baltazar Nunes[SUP] 1 [/SUP]; VEBIS-EHR working group
Affiliations
- PMID: 42504085
- DOI: 10.1080/14760584.2026.2708184
Background: We estimated the XBB.1.5 vaccine effectiveness (VE) against COVID-19 hospitalization and death in Belgium, Denmark, Italy, Portugal, Spain (Navarre), and Sweden following the 2023-24 fall vaccination campaign among immunocompromised persons (ICPs).
Research design and methods: We conducted a multi-country retrospective cohort study using electronic health records. Study sites identified ICPs aged ≥18 years through a common set of immunocompromising conditions and follow-up started the first day of the 2023 vaccination campaign until 12 months later. VE was calculated by time since vaccination (14-59, 60-119, 120-179, 180-365 days after vaccination) for ICPs by pooling study site level confounder adjusted hazard ratios (aHR) of vaccination, estimated with Cox proportional hazards regression models, using a random effect meta-analysis with VE = 100 × (1-pooled aHR).
Results: The XBB.1.5 VE was 52% (95% confidence interval (CI): 41 to 60) and 75% (95%CI: 60 to 84) against hospitalization and death, respectively, 14-59 days after vaccination, and VE decreased with time since vaccination with no remaining protection at 180-365 days after vaccination.
Conclusion: Adapted XBB.1.5 vaccine provided moderate protection within 120 days after vaccination against severe COVID-19 outcomes among ICPs aged ≥18 years during a period with BA.2.86/JN.1 replacing the XBB.1.5 variant.
Keywords: COVID-19; immunocompromised; vaccine effectiveness; viral sublineages; waning protection.