TABLE 3.

Integrated statistical analysis of the effect of age group, study, vaccination group, and prevaccination titer on rise in titers from prevaccination to week 4 postvaccination based on data combined from protocol 010 and protocol 011 (per-protocol population)

ParameterEstimated regression coefficient (95% CI)Fold difference (95% CI)a
Age group (50-59 yr vs ≥60 yr)0.119 (0.016, 0.222)1.13 (1.02, 1.25)
Study (protocol 010 vs protocol 011)0.276 (0.130, 0.422)1.32 (1.14, 1.53)
Vaccination group (Zostavax with PGSU vs Zoxtavax with PGS)c−0.131 (−0.302, 0.039)0.88 (0.74, 1.04)
Vaccination group (concomitant vs nonconcomitant)−0.068 (−0.187, 0.051)0.93 (0.83, 1.05)
One-unit increase in log-transformed prevaccination titers−0.419 (−0.461, −0.377)0.66 (0.63, 0.69)b
  • a Computed using an ANCOVA model in which the natural-log-transformed week 4 titer is the response variable and vaccination group, age, and natural-log-transformed prevaccination titers are the covariates.

  • b P < 0.001.

  • c PGSU, phosphate-gelatin-sucrose-urea; PGS, phosphate-gelatin-sucrose.