Vaccine 'effective enough'

Funding the influenza vaccine for older people is worth the cost, despite its lower effectiveness in that demographic, Auckland University Immunisation Advisory Centre director Dr Nikki Turner says.

Just how much value it has for older people is unclear, as Dr Turner has questioned the validity of a figure in the study of which she was a co-investigator, saying the sample of Auckland area patients was too small to be statistically significant.

The 2012 Southern Hemisphere Influenza, Vaccine Effectiveness, Research and Surveillance report, recently published in the journal Vaccine, indicated the flu jab was effective for only 8% of older people.

It had been the first year the study was conducted, and the research team planned to use a bigger sample size for the next one.

Overall, the flu vaccine was found to be 39% effective.

She suggested the real figure for older people could be as high as 50%, depending on the person's underlying health.

Older people needed the vaccine more, because they were more likely to catch flu, and better targeted vaccines for older people were being developed.

Asked if the money spent subsidising the jab for those 65 and over could be directed to other health needs, Dr Turner said the vaccine was cheap and ''effective enough''.

This month, the New Zealand Medical Journal published a study of Canterbury patients in the 2012 season which indicated the vaccine did not provide significant protection from the predominant strain.

University of Otago biostatistician Prof Peter Herbison said he would not accept a vaccine with only 8% effectiveness.

He emphasised that that was at a personal level, and for the population as a whole, there were probably still benefits.

''If it's only 8% effective, I would start to wonder whether it's worth it or not.''

That one in 12 older people avoided flu based on 8% effectiveness meant it was still probably a worthwhile spend of health dollars.

Vaccination sceptic Dr Tat Loo, a Dunedin chiropractor, said research demonstrated little benefit from flu vaccine.

''Overseas research suggests that concrete positive benefits from the flu vaccination can be quite minimal, so I am a bit surprised to see the NZ study suggesting such high rates [39% overall] of benefit.''

While there might be an overall reduction in flu, the likelihood of personal health benefit was low. It highlighted the tension between individual benefit and population level benefit.

Health decision-makers should focus on overall patient health, rather than being ''fixated'' on vaccination. Information was lacking about flu vaccine effectiveness, Dr Loo suggested.

''If patients cannot ascertain a clear idea of the relative magnitude of risks, benefits and unknowns surrounding a treatment, then true informed consent will be difficult or impossible to obtain.''

Including administration, the vaccine costs more than $28 per patient (excluding GST), general practice advice website Bpac says.

For subsidised groups, including those 65 and over, the vaccine is funded by the Government.

Last year, 426,796 vaccines for older people were funded by the Government, Pharmac figures show.

A spokesman for the drug buying agency said Pharmac regularly reviewed new information about medicines it funded.

''Our view is that there continues to be a population health benefit to funding influenza vaccine for the currently eligible groups.''

Mornington Health Centre figures show that of the more than 3100 patients who have had the flu vaccine so far this season, nearly 1300 were over 65.

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