Flu shots effective for seniors, says new review

Date: Nov-13-2014 A new review of published studies finds that the seasonal flu

vaccine is effective at protecting the over-60s during epidemics or

widespread outbreaks.

For people over 60, the flu vaccine is effective at protecting them during epidemics or outbreaks, according to the latest study.

Senior investigator Edwin Van den Heuvel, a professor in the

Department of Epidemiology at the University of Groningen in the

Netherlands, and colleagues report their findings in The Lancet

Infectious Diseases.

Although anyone can get the flu, the most vulnerable groups are

young children under the age of 2, the over-60s and people who are

already ill with another condition.

For their review, the researchers only included case-control studies

of "test-negative design." These have emerged in recent years as the

preferred method for assessing the effectiveness of flu vaccines

because they are thought to rule out bias due to misclassification of

infection and confounding by health care-seeking behavior.

This means the researchers only included studies that compared older

people with similar health care-seeking behavior. For example, people

less likely to visit the doctor are also less likely to get a flu shot,

so including them in the comparison sample could bias the results to

make the vaccine look more effective than it is.

Dr. Michael L. Jackson, assistant investigator with Group Health

Research in Seattle, WA, who writes an accompanying commentary on the

study, told Reuters Health that often, people who are old and

frail are less able to visit their doctor and more likely to have

complications if they do fall ill. Comparing them to healthier people

who get the shot is also going to make the vaccine look better than it is,

he explains.

Altogether, the reviewers found 35 studies covering 53 datasets -

including several from the US and Australia -
that met their inclusion criteria.

Analysis showed flu shots significantly effective during widespread

outbreaks

Overall, the analysis showed that during regional or widespread

seasonal flu activity, over-60s who received flu shots were 28-58% less

likely than others to test positive for a flu infection.

Further analysis revealed that while seasonal flu shots were not

significantly effective during local virus activity, they were

significantly effective during regional and widespread outbreaks,

regardless of whether the vaccine was a full match to circulating

viruses.

"This reinforces what we already know, the vaccine works modestly

well for seniors," says Dr. Jackson.

In their conclusions, the authors note, "efforts should be

renewed worldwide to further increase uptake of the influenza vaccine

in the elderly population."

In July 2014, Medical News Today reported a study where

researchers suggest tackling immune

response as a new direction for flu drugs, rather than trying to

tackle the virus itself. Reporting in the Journal of Virology,

they show how such an approach might work against infection by the H7N9

avian flu virus.

Written by Catharine Paddock PhD

Not to be reproduced without permission.

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Courtesy: Medical News Today Note: Any medical information available in this news section is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional.