Background There is growing consensus that COVID-19 booster vaccines may be coadministered with other age-appropriate vaccines. Adding to the limited available data supporting coadministration, especially with adjuvanted vaccines, could enhance vaccine coverage in adults. Methods In this phase 3, randomized, open-label study, eligible adults aged ≥50 years were randomly assigned (1:1) to receive mRNA-1273 (50µg) booster vaccination and a first dose of recombinant zoster vaccine (RZV1) 2 weeks apart (Seq group) or concomitantly (Coad group). The second RZV dose (RZV2) was administered 2 months post- RZV1 in both groups. Primary objectives were noninferiority of anti-glycoprotein E and anti-Spike protein antibody responses in the Coad group compared to the Seq group. Safety and further immunogenicity assessments were secondary objectives. Results 273 participants were randomized to the Seq group, 272 to the Coad group. Protocol-specified non-inferiority criteria were met. The adjusted geometric mean concentration ratio (Seq/Coad) was 1.01 (95% confidence interval [CI], 0.89–1.13) for anti-gE antibodies 1-month post-RZV2, and 1.09 (95% CI 0.90–1.32) for anti-Spike antibodies 1-month post-mRNA-1273 booster. No clinically relevant differences were observed in overall frequency, intensity, or duration of adverse events between the 2 study groups. Most solicited adverse events were mild/moderate in intensity, each with median duration ≤2.5 days. Administration site pain and myalgia were the most frequently reported in both groups. Conclusions Coadministration of mRNA-1273 booster vaccine with RZV in adults aged ≥50 years was immunologically noninferior to sequential administration and had a safety and reactogenicity profile consistent with both vaccines administered sequentially (clinicaltrials.gov NCT05047770).

BackgroundThere is growing consensus that COVID-19 booster vaccines may be coadministered with other age-appropriate vaccines. Adding to the limited available data supporting coadministration, especially with adjuvanted vaccines, could enhance vaccine coverage in adults.MethodsIn this phase 3, randomized, open-label study, eligible adults aged ≥50 years were randomly assigned (1:1) to receive mRNA-1273 (50µg) booster vaccination and a first dose of recombinant zoster vaccine (RZV1) 2 weeks apart (Seq group) or concomitantly (Coad group). The second RZV dose (RZV2) was administered 2 months post- RZV1 in both groups. Primary objectives were noninferiority of anti-glycoprotein E and anti-Spike protein antibody responses in the Coad group compared to the Seq group. Safety and further immunogenicity assessments were secondary objectives.Results273 participants were randomized to the Seq group, 272 to the Coad group. Protocol-specified non-inferiority criteria were met. The adjusted geometric mean concentration ratio (Seq/Coad) was 1.01 (95% confidence interval [CI], 0.89–1.13) for anti- gE antibodies 1-month post-RZV2, and 1.09 (95% CI 0.90–1.32) for anti-Spike antibodies 1- month post-mRNA-1273 booster. No clinically relevant differences were observed in overall frequency, intensity, or duration of adverse events between the 2 study groups. Most solicited adverse events were mild/moderate in intensity, each with median duration ≤2.5 days.Administration site pain and myalgia were the most frequently reported in both groups.ConclusionsCoadministration of mRNA-1273 booster vaccine with RZV in adults aged ≥50 years was immunologically noninferior to sequential administration and had a safety and reactogenicity profile consistent with both vaccines administered sequentially (clinicaltrials.govNCT05047770).Visual abstract