Table 2.

Vaccine efficacy against the first or only episode of herpes zoster infection, from 30 days post-second vaccination up to study end (modified exposed set).

	RZV group				Placebo group				VE
Type	N	n	T (years)	IR (per 1000 person-years)	N	n	T (years)	IR (per 1000 person-years)	% (95% CI)	p-value
Overall*	2965	0	3752.3	0.0	2991	31	3769.0	8.2	100 (89.82–100)	<.0001
50–69 years	2330	0	2957.0	0.0	2360	22	2981.8	7.4	100 (85.29–100)
≥ 70 years	635	0	795.2	0.0	631	9	787.2	11.4	100 (60.90–100)

*VE adjusted by age strata.

Note: the follow-up for each participant started (start date) 30 days after the second dose was administered and ended (stop date) at the time a herpes zoster episode was confirmed for the participant. For those participants without a confirmed herpes zoster episode, the follow-up ended at the last visit; at the last contact date for participants who withdrew from the study and did not have a confirmed herpes zoster episode; or on the date of the herpes zoster and/or varicella zoster virus vaccination that occurred outside of the study, if not preceded by an event.

T (years) is the sum of follow-up time at risk expressed in years for confirmed herpes zoster of all participants in the modified exposed set. The follow-up time at risk for confirmed herpes zoster per participant, expressed in days, is computed using the following formula: $\mathit{stopdate}-\mathit{startdate}+1$.

RZV group, participants receiving the adjuvanted recombinant zoster vaccine; placebo group, participants receiving placebo; VE, vaccine efficacy; N, number of participants included in each group; n, number of participants having at least one confirmed herpes zoster episode; T, sum of follow-up period; IR, incidence rate; CI, confidence interval.