Scientists said on Thursday
that vaccinating children against chickenpox (varicella) could increase
the risk that adults would develop shingles, a painful blistering rash
that is potentially dangerous in the elderly.
The team, at Britain's Public
Health Laboratory Service (PHLS), said that although vaccination would
save thousands of lives over time, thousands of elderly people could also
die from the complications of shingles, known as herpes zoster.
Writing in the journal Vaccine,
they called for a re-evaluation of the policy of mass chickenpox vaccination
that has been introduced already in the United States and is imminent
in many other countries. In 1995, the chickenpox vaccine was approved
for use in children over 1 year of age in the US and is now required for
After a bout of naturally-occuring
chickenpox, the varicella zoster virus remains dormant in the body and
may reactivate decades later to cause shingles, a painful rash that typically
strikes chickenpox veterans after the age of 60.
Marc Brisson and his team say
their research shows that adults living with children have more exposure
to the virus that causes chickenpox and enjoy high levels of protection
against shingles. Being close to children
means that adults are exposed to the virus, which acts like a booster
vaccine against shingles, they believe. But if all children were vaccinated,
adults who have had chickenpox would no longer be protected against developing
The researchers worked out
a mathematical model that predicts that eliminating chickenpox in a country
the size of the United States would prevent 186 million cases of the disease
and 5,000 deaths over 50 years. However they said it could also result
in 21 million more cases of shingles and 5,000 deaths.
The PHLS said in a statement
it was working out what the impact might be of
introducing a chickenpox vaccine in Britain. "As more evidence becomes
available, it will be shared with the Joint Committee on Vaccination and
Immunisation, which advises the Department of Health on the immunisation
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