May 22, 2006

Study backs high-dose flu vaccines for elderly

CHICAGO (Reuters) - Elderly people, whose immune responses
typically weaken with age, can be safely protected against
common influenza with doses of vaccine that are up to four
times stronger than usual, researchers said on Monday.

The report from Baylor College of Medicine in Houston said
most reactions to the more potent doses of vaccine were mild.
The biggest complaints involved discomfort, redness or swelling
at the site of the injection in those who got the strongest

But increasing the strength of the vaccine also brought
consistent improvements in immune responses, concluded the
study published in the current Archives of Internal Medicine.

The elderly "are among the most vulnerable to serious
complications of influenza because they generally have more
underlying diseases and weaker immune systems than younger
people," said Anthony Fauci, director of the National Institute
of Allergy and Infectious Diseases, which financed the study.

"These findings are an important first step in developing
new strategies to better protect the elderly against
influenza-associated hospitalizations and mortality," he added.

In the United States seasonal flu causes 36,000 deaths and
more than 200,000 hospitalizations every year, affecting up to
20 percent of the population.

The Baylor study involved 202 adults with an average age of
77 who were given doses of seasonal flu vaccine at normal doses
and at doses twice and four times more potent than normal.

Blood tests showed that those who had received the
strongest dose had 44 to 79 percent higher levels of flu
antibody after they were inoculated than did those who received
the normal dose of vaccine, the study found.