RSV and Flu Vaccine Coadministration Found Safe

With the 2023-2024 influenza season accelerating in late 2023, a recent study reported good news for seniors also concerned about Respiratory syncytial virus (RSV) disease.

Published in the journal Clinical Infectious Diseases on November 22, 2023, researchers found that the ABRYSVO™ bivalent RSVpreF vaccine and seasonal inactivated influenza vaccine (SIIV) can be safely coadministered to individuals 65 years and older.

Furthermore, immune responses met the prespecified immunogenicity endpoint for noninferiority for both respiratory vaccines.

The study's results included geometric mean ratios of 0.86 for RSV-A and 0.85 for RSV-B neutralizing titers at one month after RSVpreF administration and 0.77 to 0.90 for strain-specific hemagglutination inhibition assay titers at one month after SIIV.

All comparisons achieved the prespecified 1.5-fold noninferiority margin.

These researchers wrote that by eliminating the need for an additional vaccination visit, coadministration of RSV and influenza vaccines for individuals recommended to receive both vaccines may offer convenience to patients and healthcare providers.

Coadministration of influenza vaccines with other respiratory vaccines, such as pneumococcal disease, has also been shown to be safe and immunogenic.

Although this Pfizer Inc.-funded study was conducted in older adults, these researchers expect that the favorable safety profile and robust immunogenicity observed with coadministration would support broader application.

The study was conducted in adults 65 years and older, a population well recognized for being substantially at risk for severe complications of both RSV illness and influenza infection.

Strengths of this study include the randomized, double-blind design, which enabled the comparison of RSVpreF and SIIV coadministration to sequential administration while providing all participants with both vaccines.