High-Dose Flu Shot Boosted Immunity in Elderly

High dose flu vaccine produced stronger immune response in elderly patients living in long term care

(RxWiki News) A high-dose flu vaccine isn’t any more fun than the regular version, but if you have to be stuck with a needle to prevent the flu, it’s nice to know it works well.

High-dose flu vaccines produced a stronger immune response than standard doses in a study of elderly adults who lived in long-term care facilities. Patients in these facilities are often older and frail, which means the flu could pose serious health risks for them.

The authors of this study said long-term care facilities should vaccinate patients and workers, conduct surveillance for respiratory diseases and use antiviral medications when needed.

"For frail older adults, the high-dose vaccine appears to be a better option to protect against flu than the standard dose," said study leader David A. Nace, MD, of the University of Pittsburgh, in a press release. "Even in the frail, long-term care population, the high-dose flu vaccine looks like it produces a greater antibody response than the standard dose vaccine."

The high-dose vaccine was developed specifically for older adults and has only been in use since 2009. This study did not assess whether these adults actually got the flu, but past research has shown that a stronger immune response often translated to lower flu rates and fewer hospitalizations.

The flu poses the greatest health risks to older adults, according to the Centers for Disease Control and Prevention (CDC).

People who are 85 and older face a very high risk from the flu. Those who live in long-term care facilities may have an increased risk because they are more likely to be exposed to the virus. The elderly are also more likely to have impaired immunity from other medical conditions or because of medications.

Dr. Nace and team looked at 187 frail older adults from 15 long-term care facilities in western Pennsylvania during the 2011 to 2012 and 2012 to 2013 flu seasons. The average age of these study patients was 86.7 years old.

These researchers collected blood samples from patients at 30 and 180 days after vaccination and checked the level of flu antibodies — called a titer — in their blood. The researchers found that the high-dose vaccine produced a stronger immune response than standard-dose vaccines. Dr. Nace noted that the immune response boost was modest.

The actual antibody titers varied according to the strain of the flu virus. Flu vaccines are typically mixtures of viral strains designed to provide immunity against the most likely flu viruses circulating in a given year. A high-dose vaccine is about four times stronger than a standard vaccine.

Although high-dose vaccines may protect frail elderly patients, other strategies are also necessary, Dr. Nace and team noted. Immunizing health care workers may also decrease patient exposure to the flu.

When flu does occur, health care facilities should take immediate steps to contain its spread, such as isolating patients or having people wear masks.

This study was published Dec. 17 in The Journal of Infectious Diseases.

Grants from Sanofi Pasteur and from the University of Pittsburgh Claude D. Pepper Older Americans Independence Center funded this research.

Study authors Dr. Richard K. Zimmerman and Dr. Chyongchiou Jeng Lin received research grants from Pfizer, Merck and Sanofi Pasteur. Dr. Jeng Lin consulted for MedImmune. Dr. Ted M. Ross has received funding from Sanofi Pasteur to develop a universal influenza vaccine. The companies listed make flu vaccines or medications to treat the flu.

Review Date: 
December 21, 2014