Shingles (herpes zoster) occurs when the same virus that causes chickenpox is reactivated later in life. Until recently, there was no known cure for shingles and the virus would simply run its course and disappear after two to three weeks.
Now a new study found that a vaccination greatly reduces the risk of serious complications from shingles.
The new study showed the vaccine was 74% effective in preventing hospitalisation for shingles during the three years after vaccination. That number dropped to 55% effective after four or more years.
The immunisation was 57% effective for preventing lasting pain in the three years after vaccination. The rate dropped to 45% after four years, the researchers said.
The findings were published recently in the journal Clinical Infectious Diseases.
"The fact that we found relatively high effectiveness against serious outcomes, such as hospitalisation and [lasting pain], and that protection from these outcomes was sustained over time, adds to the considerable evidence that the vaccine is beneficial and that seniors should be encouraged to be vaccinated in higher numbers than what is happening currently," study author Dr Hector Izurieta said in a journal news release.
Izurieta is with the US Food and Drug Administration's Center for Biologics Evaluation and Research. The FDA funded the research.
The study looked at information collected between 2007 and 2014. The data included about 2 million Medicare (the American national social medical insurance) beneficiaries. The researchers found that the vaccine seems most effective against severe cases of shingles requiring hospitalisation and against chronic pain.
There didn't seem to be much difference in how effective the vaccine was between age groups. But protection declined over time after vaccination, the researchers said.
To conclude, the shingles vaccine is safe, has few side effects and will protect most people for at least five years.
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