Comparative effectiveness of the bivalent COVID-19 mRNA vaccines, mRNA1273-222 and BNT162b2, in immunocompromised adults in the US.

person Hagit Kopel Moderna, Inc., Cambridge, MA info_outline Hagit Kopel, Van Hung Nguyen, Alina Bogdanov, Isabelle Winer, Catherine Boileau, Thierry Ducruet, Ni Zeng, Mary Bausch-Jurken, Daina B. Esposito, Ekkehard Beck, Mac Bonafede, James A. Mansi

Authors person Hagit Kopel Moderna, Inc., Cambridge, MA info_outline Hagit Kopel, Van Hung Nguyen, Alina Bogdanov, Isabelle Winer, Catherine Boileau, Thierry Ducruet, Ni Zeng, Mary Bausch-Jurken, Daina B. Esposito, Ekkehard Beck, Mac Bonafede, James A. Mansi Organizations Moderna, Inc., Cambridge, MA, VHN Consulting Inc, Montreal, QC, Canada, Veradigm, Chicago, IL Abstract Disclosures Research Funding Moderna, Inc. Background: Despite the decline in COVID-19–related hospitalizations and mortality during the period of omicron predominance, immunocompromised individuals, including those with cancer, remain at an increased risk for severe COVID-19 outcomes. A subanalysis of a retrospective observational cohort study assessed the relative vaccine effectiveness (rVE) of 2 previously approved bivalent vaccines targeting the ancestral SARS-CoV-2 and the omicron BA.4/BA.5 variant, mRNA-1273.222 (Moderna, Inc., Cambridge, MA, USA) and BNT162b2 bivalent (Pfizer Inc., New York, NY, USA; BioNTech GmbH, Mainz, Germany), in immunocompromised adults in the United States. Methods: The study used a US electronic health record dataset (Veradigm) linked with medical and pharmacy claims data of adults aged ≥18 years with at least 1 underlying medical condition associated with increased risk of severe COVID-19 who received a dose of mRNA-1273.222 or BNT162b2 bivalent vaccines between August 31, 2022, and February 28, 2023. A subgroup analysis was conducted among an immunocompromised population, encompassing cancer patients, organ or stem cell transplant recipients, individuals with primary immunodeficiency, individuals with HIV, and individuals receiving immunosuppressing medications. Comorbid conditions were based on prior medical encounters in the 365 days before vaccination. The outcomes measured were rVE of the two bivalent mRNA vaccines against COVID-19-related hospitalizations (primary outcome) and outpatient visits (secondary outcome). Follow-up started 7 days after vaccination until May 31, 2023 (end of available claims data). Propensity score weighting was used to adjust for baseline differences between groups. Results: The subanalysis included 427,260 immunocompromised individuals, of which 250,573 (58.6%) were identified as having cancer. In the overall weighted immunocompromised population, 169,509 individuals received mRNA-1273.222, and 257,751 received BNT162b2 bivalent. The adjusted rVEs of mRNA-1273.222 versus BNT162b2 bivalent vaccine against COVID-19–related hospitalizations and outpatient visits were 15.0% (95% CI, 7.2%-22.0%; P < 0.001) and 4.8% (95% CI, 1.8%-7.7%; P = 0.002), respectively. Conclusions: In this study, the mRNA-1273.222 vaccine offered greater protection against COVID-19–related hospitalization compared with the BNT162b2 bivalent vaccine among immunocompromised individuals. This study emphasizes the importance of assessing COVID-19 vaccine formulations and optimizing protection, especially in immunocompromised adults, including those with cancer.