Massive flu vaccine dose protects elderly better

WASHINGTON (Reuters) - Giving four times the usual dose of flu vaccine helps protect elderly people better than the usual dose, researchers reported on Sunday, offering a potential solution to the problem of vaccinating seniors.

Recent research has shown the standard flu vaccine does not reduce deaths noticeably among the elderly, who make up most of the 36,000 people a year in the United States who die of influenza each year.

This is likely because their immune systems are not as active as those of younger people.

Dr. Ann Falsey of the University of Rochester School of Medicine and Dentistry and colleagues tried giving a much bigger dose of flu vaccine to see if that might help.

They tested the idea on 3,800 volunteers aged 65 and older and found their bodies produced up to twice as many antibodies -- the immune system proteins that help attack invaders such as viruses -- compared to seniors given the usual vaccine dose.

The patients had many different chronic conditions and many were considered at high risk of complications from flu but the high-dose vaccine appeared to work well in them all, the researchers told a joint meeting of the American Society for Microbiology and Infectious Diseases Society of America.

The study was paid for by flu vaccine maker Sanofi Pasteur, which makes one of the flu vaccines licensed for use in the United States. It hopes to license the higher-dose vaccine for older patients

"The goal is to increase immune response in older adults, since this is one of the populations most at risk for becoming seriously ill or dying from influenza," Falsey said in a statement.

Annual flu vaccines are recommended for most of the U.S. population, including people over the age of 50, people with chronic conditions such as diabetes, children and pregnant women. Globally, seasonal influenza kills between 250,000 and 500,000 people every year.

(Reporting by Maggie Fox; Editing by Bill Trott)