Half the people in the study got the vaccine, and half didn't. The results:
- The vaccine cut shingles cases by 51%.
- The vaccine reduced shingles severity by 61%.
- The vaccine reduced cases of postherpetic neuralgia by 66.5%.
That last number is the most important one, says herpes virus expert Sam Speck, PhD, professor of microbiology and immunology at the Emory Vaccine Center and director of the center for emerging infectious diseases at Emory University in Atlanta.
"For individuals over 60, it may be worth getting vaccinated if this vaccine becomes available," Speck tells WebMD. "If the vaccine's protection was simply limited to preventing the bout of shingles, it would be less of a good idea. But it is the prevention of postherpetic neuralgia that really drives interest in this vaccine."
Merck, which makes the vaccine, already has asked the FDA to approve the vaccine. But it's not easy to make. Right now, Oxman says, his team is waiting for Merck to give them more vaccine so they can give it, as promised, to the nearly 20,000 study participants who received placebo during the study. Merck is a WebMD sponsor.
Questions remain about the shingles vaccine, notes Stanford University researcher Ann Arvin, MD. Arvin's editorial accompanies the Oxman study in the NEJM.
Arvin points out that:
- It's still not clear how long the vaccine protects against shingles and postherpetic neuralgia.
- It's still not clear whether repeat doses of the vaccine will improve protection.
- If a second or third dose is needed, the best vaccination schedule is not known.
- It's still not clear whether the vaccine will work in very old people.