Influenza vaccines: Poor evidence for effectiveness in elderly

Feb 17, 2010

Evidence for the safety and efficacy of influenza vaccines in the over 65s is poor, despite the fact that vaccination has been recommended for the prevention of influenza in older people for the past 40 years. These are the conclusions of a new Cochrane Systematic Review.

Adults aged 65 and over are some of the most vulnerable during season and a priority for vaccination programmes. However, very few systematic reviews of the effectiveness of vaccines in this group have ever been carried out.

The researchers conducted a thorough search of studies based on previous trials. Randomised controlled trials (RCTs) are often considered the "gold standard", but of the 75 studies included in their review, the researchers were only able to identify one recent RCT with "real" outcomes. In other words, this was the only RCT that used influenza cases as an outcome, as opposed to surrogate outcomes such as measurements of influenza antibodies in the blood. All the other studies included in the review were deemed of low quality and open to bias.

Limited reliable evidence from the studies suggests that the effectiveness of influenza vaccines is modest at best. "Our estimates are consistently below those usually quoted by economists and in decision making," says lead researcher Tom Jefferson of the Cochrane Collaboration in Rome, Italy. "But until we have all available evidence, it is hard to reach any clear conclusions about the effectiveness of influenza vaccines in older people."

"As the evidence is so scarce at the moment, we should be looking at other strategies to complement vaccinations. Some of these are very simple things like personal hygiene, and adequate food and water," says Jefferson. "Meanwhile, we need to undertake a high quality, publicly funded trial that runs over several seasons to try to resolve some of the uncertainties we're currently facing."

Jefferson is also one of the authors of a second review publishing this week, which focuses on the efficacy of influenza vaccinations in healthcare workers who work with the elderly. The results are also inconclusive, with each of the four trials included in the review being of inadequate quality and reaching implausible conclusions. The researchers were unable to draw any conclusions about whether vaccinating healthcare workers helps to prevent influenza symptoms and death in people aged over 60.

Explore further: Philippines boosts MERS monitoring after UAE nurse scare

add to favorites email to friend print save as pdf

Related Stories

Predicting effectiveness of flu vaccination campaigns

Feb 09, 2010

A new study, published by Elsevier this month in Vaccine, describes a new method that assesses the impact and cost-effectiveness of a range of vaccination options. The model was applied to the 2009 Influenza H1N1 outbreak and pr ...

New hospital standards needed for pediatric flu vaccines

Feb 04, 2008

A new study published in the February 2008 issue of Pediatrics finds that many children hospitalized for influenza have had a recent, previous hospitalization that would have provided an easy, convenient opportunity to rec ...

Recommended for you

US orders farms to report pig virus infections

15 hours ago

The U.S. government is starting a new program to help monitor and possibly control the spread of a virus that has killed millions of pigs since showing up in the country last year.

Foreigner dies of MERS in Saudi

16 hours ago

A foreigner has died after she contracted MERS in the Saudi capital, the health ministry said on announced Friday, bringing the nationwide death toll to 73.

Vietnam battles fatal measles outbreak

19 hours ago

Vietnam is scrambling to contain a deadly outbreak of measles that has killed more than 100 people, mostly young children, and infected thousands more this year, the government said Friday.

New clues on tissue scarring in scleroderma

20 hours ago

A discovery by Northwestern Medicine scientists could lead to potential new treatments for breaking the cycle of tissue scarring in people with scleroderma.

User comments : 0

More news stories

Treating depression in Parkinson's patients

A group of scientists from the University of Kentucky College of Medicine and the Sanders-Brown Center on Aging has found interesting new information in a study on depression and neuropsychological function in Parkinson's ...

Health care site flagged in Heartbleed review

People with accounts on the enrollment website for President Barack Obama's signature health care law are being told to change their passwords following an administration-wide review of the government's vulnerability to the ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.