RSV Vaccine Combo Shows Promise for Enhanced Protection

Adding recombinant respiratory syncytial virus (RSV) prefusion conformation-stabilized RSV fusion (preF) protein to the Ad26.RSV.preF vaccine increased humoral immunogenicity in people aged 60 and older, according to a study published online ahead of print in The Journal of Infectious Diseases.

“Ad26.RSV.preF is an adenovirus serotype 26 vector–based RSV vaccine encoding a preF protein that demonstrated robust humoral and cellular immunogenicity and showed promising efficacy in a human challenge study in younger adults,” explained corresponding author Christy A. Comeaux, MD, PhD, of Janssen Vaccines & Prevention BV, the Netherlands, and coauthors in the study background.

To see whether a combination regimen of Ad26.RSV.preF plus RSV preF protein would enhance RSV-specific humoral immune response, particularly in older people; investigators conducted a phase 1/2a study. Researchers compared the safety and immunogenicity of Ad26.RSV.preF alone and varying doses of Ad26.RSV.preF–RSV preF protein combinations. The study included data from an initial safety cohort of 64 participants aged 60 and older and a regimen selection cohort spanning 288 participants aged 60 and older.

At 28 days after vaccination, “combination regimens induced greater humoral immune responses (virus-neutralizing and preF-specific binding antibodies) and similar cellular ones (RSV-F–specific T cells) as compared with Ad26.RSV.preF alone,” researchers reported.

In fact, vaccine-induced immune responses were still above baseline as long as 18 months after vaccination, the study showed.

Safety analyses 28 days after vaccination showed similar reactogenicity profiles for all vaccine regimens. Researchers categorized all regimens as well tolerated.

“Among the regimens tested, the combination of Ad26.RSV.preF (1 × 1011 viral particles) and RSV preF protein (150 µg; high dose-high dose) was selected for further development,” the authors wrote.

Reference:
Comeaux CA, Bart S, Bastian AR, et al. Safety, immunogenicity, and regimen selection of Ad26.RSV.preF-based vaccine combinations: a randomized, double-blind, placebo-controlled, phase 1/2a study. J Infect Dis. Published online July 11, 2023. doi:10.1093/infdis/jiad220