Immunogenicity and Safety of Coadministration of AS01E-Adjuvanted Respiratory Syncytial Virus Prefusion F Protein Vaccine and a COVID-19 mRNA Vaccine in Adult s Aged ≥50 Years: A Phase 3, Randomized, Noninferiority Trial
Abstract
Background: This trial evaluated coadministration of the AS01E-adjuvanted respiratory syncytial virus (RSV) prefusion F protein-based vaccine (adjuvanted RSVPreF3) and an Omicron XBB.1.5-based coronavirus disease 2019 (COVID-19) mRNA vaccine in ≥50-year-olds.
Methods: This phase 3, open-label, multicenter trial randomized ≥50-year-olds 1:1 to coadministration (Co-Ad group) or sequential administration approximately 1 month apart (Control group) of adjuvanted RSVPreF3 and the COVID-19 mRNA vaccine. Primary objectives were to demonstrate noninferiority of humoral immune responses at 1 month postvaccination in terms of RSV-A, RSV-B, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing titers, with the upper limit of the 95% CI of adjusted geometric mean titer (GMT) group ratios (Control/Co-Ad) ≤1.50. Secondary objectives included assessment of reactogenicity up to 4 days and safety up to 6 months after vaccination.
Results: Overall, 833 participants were vaccinated (Co-Ad: 417; Control: 416). Noninferiority was achieved for RSV-A (GMT ratio: 1.12 [95% CI: .97–1.28]) and RSV-B (GMT ratio: 1.08 [95% CI: .94–1.23]) and marginally missed for SARS-CoV-2 Omicron XBB.1.5 (GMT ratio: 1.31 [95% CI: 1.13–1.51]). Within 4 days postvaccination, the most frequently reported solicited events were administration-site pain, myalgia, and fatigue. Most solicited events were of mild-to-moderate intensity, and the overall median duration was ≤3 days and comparable between groups. Unsolicited and serious adverse events were generally balanced between groups.
Conclusions: Adjuvanted RSVPreF3 coadministered with a COVID-19 mRNA vaccine maintained an acceptable safety profile in ≥50-year-olds. The marginal miss of the noninferiority criterion for SARS-CoV-2 does not suggest clinically relevant interference. Therefore, the results support the coadministration of these vaccines.
Clinical Trials Registration: Clinical Trials.gov. NCT06374394.
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BibTeX
@article{bonten2026immunogenicity,
title = {{Immunogenicity and Safety of Coadministration of AS01E-Adjuvanted Respiratory Syncytial Virus Prefusion F Protein Vaccine and a COVID-19 mRNA Vaccine in Adult s Aged ≥50 Years: A Phase 3, Randomized, Noninferiority Trial}},
author = {Marc Bonten and Brandon Essink and Nikita Hanning and Isabel Leroux-Roels and Cristina Masuet-Aumatell and Silvina Natalini Martinez and Hiwot Amare Hailemariam and Ghassem Jandari and Paulia Kwo Ton Ge Jua and Charlotte Servais and Sofía Valenciano and Archana M Jastorff and Vicky Cárdenas and Marie Van der Wielen},
journal = {Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America},
year = {2026},
month = jun,
doi = {10.1093/cid/ciag344},
url = {https://doi.org/10.1093/cid/ciag344},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Immunogenicity and Safety of Coadministration of AS01E-Adjuvanted Respiratory Syncytial Virus Prefusion F Protein Vaccine and a COVID-19 mRNA Vaccine in Adult s Aged ≥50 Years: A Phase 3, Randomized, Noninferiority Trial
AU - Marc Bonten
AU - Brandon Essink
AU - Nikita Hanning
AU - Isabel Leroux-Roels
AU - Cristina Masuet-Aumatell
AU - Silvina Natalini Martinez
AU - Hiwot Amare Hailemariam
AU - Ghassem Jandari
AU - Paulia Kwo Ton Ge Jua
AU - Charlotte Servais
AU - Sofía Valenciano
AU - Archana M Jastorff
AU - Vicky Cárdenas
AU - Marie Van der Wielen
PY - 2026
DA - 2026/06/04
JO - Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America
DO - 10.1093/cid/ciag344
UR - https://doi.org/10.1093/cid/ciag344
AB - Background: This trial evaluated coadministration of the AS01E-adjuvanted respiratory syncytial virus (RSV) prefusion F protein-based vaccine (adjuvanted RSVPreF3) and an Omicron XBB.1.5-based coronavirus disease 2019 (COVID-19) mRNA vaccine in ≥50-year-olds. Methods: This phase 3, open-label, multicenter trial randomized ≥50-year-olds 1:1 to coadministration (Co-Ad group) or sequential administration approximately 1 month apart (Control group) of adjuvanted RSVPreF3 and the COVID-19 mRNA vaccine. Primary objectives were to demonstrate noninferiority of humoral immune responses at 1 month postvaccination in terms of RSV-A, RSV-B, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing titers, with the upper limit of the 95% CI of adjusted geometric mean titer (GMT) group ratios (Control/Co-Ad) ≤1.50. Secondary objectives included assessment of reactogenicity up to 4 days and safety up to 6 months after vaccination. Results: Overall, 833 participants were vaccinated (Co-Ad: 417; Control: 416). Noninferiority was achieved for RSV-A (GMT ratio: 1.12 [95% CI: .97–1.28]) and RSV-B (GMT ratio: 1.08 [95% CI: .94–1.23]) and marginally missed for SARS-CoV-2 Omicron XBB.1.5 (GMT ratio: 1.31 [95% CI: 1.13–1.51]). Within 4 days postvaccination, the most frequently reported solicited events were administration-site pain, myalgia, and fatigue. Most solicited events were of mild-to-moderate intensity, and the overall median duration was ≤3 days and comparable between groups. Unsolicited and serious adverse events were generally balanced between groups. Conclusions: Adjuvanted RSVPreF3 coadministered with a COVID-19 mRNA vaccine maintained an acceptable safety profile in ≥50-year-olds. The marginal miss of the noninferiority criterion for SARS-CoV-2 does not suggest clinically relevant interference. Therefore, the results support the coadministration of these vaccines. Clinical Trials Registration: Clinical Trials.gov. NCT06374394.
SN - 1058-4838
SN - 1537-6591
ER -