Aims: Vaccines against RSV disease and herpes zoster is available and recommended in older adults. Co-administration of RSVPreF3 OA and RZV was assessed in ≥50-year-olds.
Methods: In this phase 3, open-label, multi-country study (NCT05966090), participants were 1:1 randomized to receive RZV dose1 and RSVPreF3 OA concomitantly at visit 1 (Co-ad) or RZV dose1 alone (Control). Control group received RSVPreF3 OA at day (D) 31. RZV dose2 was administered at D61. Objectives: non-inferiority of immune responses in Co-ad versus Control (primary; criteria: upper limit of 95% confidence interval [CI] of geometric mean concentration [GMC] and titer [GMT] ratios ≤1.5 for RZV and RSV, respectively). Secondary endpoints: Reactogenicity/safety.
Results: 530 participants (Co-ad:265; Control:265) were vaccinated. Non-inferiority criteria were met: anti-glycoprotein E antibody GMC ratio was 1.24 (95%CI:1.08-1.42); RSV-A and RSV-B neutralizing GMT ratios were 1.14 (95%CI:0.97-1.35) and 0.98 (95%CI:0.84-1.15). Within 7D post-vaccination, administration site solicited events were reported by 73.6% (Co-ad, post-RZV dose1+RSVPreF3 OA [Gr3=3.9%]), 60.4% (Control, post-RZV dose1 [Gr3=1.9%]) and 48.8% (Control, post-RSVPreF3 OA [Gr3=1.2%]) of participants; at visit 1 systemic solicited events were reported by 73.6% (Co-ad [Gr3=9.3%]) and 60.4% (Control [Gr3=5.8%]) of participants. Duration of solicited events was short and comparable. Unsolicited adverse events were balanced between groups with grade 3 events ≤0.8%. Two participants (1 Co-ad/1 Control) reported potential immune-mediated diseases. No fatal, related serious adverse events, GBS or acute disseminated encephalomyelitis were reported.
Conclusions: Immune data supports co-administration of RSVPreF3 OA and RZV (both AS01-adjuvanted) with clinically acceptable reactogenicity/safety profile.
Funding: GSK. Encore abstract from EuGMS 2024