From Autumn 2013, people in their 70s are being offered a vaccination on the NHS to protect against shingles. Previously, vaccination was only available via private prescription.
Shingles is an infection caused by the same virus that causes chickenpox, the herpes varicella-zoster virus. It results in a rash that can be mildly itchy to intensely painful.
There's also the risk of long-term nerve pain, called post-herpetic neuralgia.
The shingles vaccine
The vaccine, called Zostavax, is given as a single injection under the skin (subcutaneously). It can be given at the same time as the seasonal flu jab, but unlike flu, repeat injections are not needed.
The vaccine has been tested for safety in clinical trials involving more than 32,000 adults.
In rare cases there may be an allergic reaction to the vaccine and one of its components, neomycin. This includes skin rash or contact dermatitis.
Shingles and ageing
Elderly people are at particular risk of shingles. The Department of Health says the vaccination programme will prevent 38% of the 30,000 cases seen every year in people over 70.
A large US study involving more than 760,000 people aged 65 and over found vaccination halved the chances of developing shingles.
The study published in PLoS Medicine found than without the jab, 10 in 1,000 people a year would develop shingles. After vaccination, that fell to five in 1,000.
Even if the vaccine doesn't stop a person developing shingles, a 55% reduction in symptoms is possible.
The UK-wide vaccination programme begins in September 2013. Initially, people aged 70 and aged 79 in England, Scotland and Northern Ireland will be offered the vaccine. In Wales, those aged 78 and 79 will be offered the vaccination first.
In subsequent years more of the 70 to 79 year olds will be offered vaccination.
It is estimated that 800,000 people will be eligible for the vaccine in the first year.
The Shingles Support Society is campaigning for shingles vaccination to begin earlier, at 60. The charity says this is because shingles can occur at any age.
The vaccine is licensed in Europe for adults over 50.