health
What They Don’t Tell You About the Shingles Vaccine
The headline number is 97% effective. The number that actually matters to you is closer to 3%. Both are true. Here's what's going on — and why the distinction matters.
TL;DR
- The headline "97% effective" for the shingles vaccine (Shingrix) refers to relative efficacy, meaning it reduced the rate of shingles compared to a placebo.
- The absolute benefit is much lower, as only about 3.5% of unvaccinated individuals in the 60-69 age group developed shingles over three years.
- Postherpetic neuralgia (PHN) is a painful complication of shingles that can persist for months or years, with no cure.
- The number needed to treat (NNT) to prevent one case of shingles over three years in the 60-69 age group is approximately 30.
- Side effects from Shingrix are common, with 78-84% of vaccinated individuals reporting reactions, and approximately 1 in 11 people aged 50-69 experiencing a grade 3 reaction severe enough to disrupt daily life.
- Trial data has limitations, including potential unblinding due to visible vaccine differences and distinctive reactions, and all pivotal trials were funded by the manufacturer, GlaxoSmithKline.
- Long-term efficacy data has a flaw because there were no unvaccinated control groups after the initial trial period.