A new type of vaccine against shingles is much more effective in older people but poses greater risk of side effects, according to the findings of a major clinical trial in The New England Journal of Medicine (NEJM). Shingles is a painful rash caused by reactivation of childhood chickenpox virus, and it becomes more common with age.
The NEJM study involved more than 15,000 participants 50 and older. The new vaccine was 97% to 98% effective across all age groups. Over 3.2 years, the study documented only six cases of shingles in people who got the new vaccine, compared with 210 cases in those who received a placebo. This is potentially a big improvement over the older shingles vaccine, called Zostavax. In people in their 50s, Zostavax is 70% effective, but this drops by almost half in people 70 and older.
However, about twice as many people in the study who received the new vaccine reported side effects. The most commonly reported ones were pain at the injection site and muscle aches, although most were mild to moderate and lasted only a day or so. The new vaccine is not approved yet, so men concerned about shingles will need to wait for the new shot or have the current version now, despite its lower effectiveness in those most at risk of shingles.