Protection From the Shingles Vaccine Held Up Year After Year

CATEGORY: IMMUNE HEALTH

The shingles vaccine asks a fair amount of you: two doses, a sore arm, sometimes a rough day after each one. A natural question follows. How long does what you bought actually last? The final analysis of the vaccine’s long-term trial now has an answer that reaches eleven years. Through that whole stretch, Shingrix prevented about 88% of expected shingles cases, and even in the later years it was still stopping roughly 8 in 10.¹

Two Big Trials, Then the Long Watch

The story starts with two of the largest vaccine trials ever run in older adults. Between them, ZOE-50 and ZOE-70 enrolled about 29,000 people aged 50 and up, and a random draw decided who received the real vaccine and who received placebo shots. Nobody involved knew who’d gotten which. Over the first three to four years, the vaccine prevented 97% of shingles cases in adults 50 and older, and 91% in those 70 and older.^2,3 The new study followed 7,273 of the vaccinated participants onward, out to more than 11 years after their shots.¹ There’s a wrinkle, though. Once the vaccine was approved, the placebo participants were offered it too, as ethics required. So for the later years there was no unvaccinated group left to compare against. The researchers instead projected how many cases would have been expected without vaccination, using the shingles rates from the original trials’ own placebo groups, adjusted for age and region.

Sixty-Nine Cases, Where 341 Were Projected

During the extension years, 69 confirmed shingles cases occurred among the vaccinated participants. The projection said about 341 would have been expected without the vaccine. That works out to 79.8% protection across roughly years six through eleven, and 82% in year eleven itself, though with fewer people still enrolled by then, that last figure comes with wider uncertainty. Counted from the first year onward, cumulative protection was 87.7%. Protection looked even stronger against the complication people fear most: postherpetic neuralgia, the nerve pain that can keep burning for months after the rash heals, was reduced by 87.5%. Immune markers told the same story. Antibody and T-cell levels settled onto a plateau roughly five to seven times higher than before vaccination and stayed there. No serious side effects tied to the vaccine turned up during the follow-up.¹

A Projection Isn’t a Placebo Group

The honest caveat is the comparison itself. A projected case count is a model, not a crowd of real unvaccinated people, and the later-year estimates lean on it entirely. It’s also worth knowing that GSK, the vaccine’s maker, funded and ran the study. The obvious next question is whether protection eventually gives out and needs topping up. This study can’t see past year eleven. What it can say is that within its window, protection never collapsed, the immune plateau held level, and the authors concluded the benefit was sustained through the full follow-up.¹

Key Takeaways

• Eleven years after vaccination, Shingrix was still preventing about 8 in 10 shingles cases in its long-term trial follow-up, and 87.7% cumulatively from year one.
• Protection against postherpetic neuralgia, the lingering nerve pain that is shingles’ most feared complication, was 87.5% during the extension years.
• The later-year figures rest on a projection built from the original trials’ placebo groups rather than a live unvaccinated comparison, so they carry more uncertainty than the original randomized results.
• What happens beyond year eleven is still unknown, and the study was funded and run by the vaccine’s manufacturer.

References

1. Strezova A, Díez Domingo J, Cunningham AL, et al. Final analysis of the ZOE-LTFU trial to 11 years post-vaccination: efficacy of the adjuvanted recombinant zoster vaccine against herpes zoster and related complications. eClinicalMedicine. 2025;83:103241. link
2. Lal H, Cunningham AL, Godeaux O, et al. Efficacy of an adjuvanted herpes zoster subunit vaccine in older adults. N Engl J Med. 2015;372(22):2087–2096. link
3. Cunningham AL, Lal H, Kovac M, et al. Efficacy of the herpes zoster subunit vaccine in adults 70 years of age or older. N Engl J Med. 2016;375(11):1019–1032. link