Róisín Shortall (Dublin North West, Social Democrats)
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658. To ask the Minister for Health if his attention has been drawn to the fact the flu strain H3N2 component of the 2017 vaccine programme has been shown to have been less effective in combatting the spread of influenza than in previous years; the Health Service Executive's plans in respect of the pressure that an upswing in influenza admissions will have on the hospital system this winter season; and if he will make a statement on the matter. [45812/17]

Simon Harris (Wicklow, Fine Gael)
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Flu vaccine is the best protection against the flu. The Centre for Disease Control and Prevention (CDC) in the USA states that the influenza vaccine is 50-60% effective in preventing hospitalisation among elderly persons and 80% effective in preventing death among elderly persons.

It is too early to tell how effective this season’s flu vaccine will be, as there is very little influenza in circulation in Ireland or the rest of the Northern Hemisphere. It is only when influenza viruses are circulating that a determination can be made whether circulating flu strains match the 2017/2018 northern hemisphere flu vaccine. Influenza vaccine effectiveness (VE) data are usually not available at European or global level until mid- to late-season.

In Europe influenza vaccine effectiveness studies were initiated by the European Centre for Disease Control (ECDC) and have been followed systematically since the influenza season 2008–09 by a network of public health and academic researchers (I-MOVE). Influenza vaccine effectiveness is determined by several multicentre primary care and hospital based case–control studies and analyses.

In general, a vaccine effectiveness of approximately 40-60% has been estimated for the three different influenza A (H1N1, H3N2) and B strains (Victoria or Yamagata lineages) (these are the strains in the current flu vaccine).

The US Centers for Disease Control and Prevention (CDC) states that recent studies show that flu vaccination reduces the risk of flu illness by between 40% and 60% among the overall population during seasons when most circulating flu viruses are well-matched to the flu vaccine see www.cdc.gov/flu/about/qa/vaccineeffect.htm .

In the Northern Hemisphere, the majority of influenza VE estimates for influenza A (H3N2) were less than 50% for the 2016/2017 influenza season. This has been the case for the past 9 seasons. Influenza vaccines provide substantial protection against influenza A(H1N1)pdm09 and influenza B, and reduced protection against influenza A(H3N2).

A systematic review and meta-analysis of influenza VE global studies from 2004-2015 was published last year in Lancet. www.thelancet.com/journals/laninf/article/PIIS1473-3099(16)00129-8/abstract.

Effective: the effectiveness is the amount of protection the vaccine offers against circulating strains i.e. influenza A (H3N2), A (H1N1) and B.

Also there are host factors as the elderly may not mount a good response due to a relatively weaker immune system. Those with chronic illness or immunosuppression don't mount the same response as healthy people. The vaccine effectiveness can wane over the season also as the virus evolves. The vaccine can be up to 70% effective against one or two types/subtypes/strains e.g. B or H1N1 and not as effective against H3N2 hence the overall quoted effectiveness against all influenza may decline as the flu season progresses.

I recently met with senior officials from my Department and the Health Service Executive for an update on influenza plans for the coming season.

A National Steering Group is currently in place and each Hospital group and Community Health Organisation have developed plans, based on lessons learned from last year. These include additional measures to vaccinate health care workers, as well as measures to control flu in long term care facilities. The Health Service Executive is also running a programme for immunising at risk groups including people over 65 years of age and pregnant women.

The Chief Medical Officer has been in contact with his counterparts in Northern Ireland and the UK, and at EU level, and all of the available data shows that influenza activity in Ireland is currently low but this is being monitored very closely in advance of the flu season when it can be expected to increase.

An additional 60,000 doses of the flu vaccine have been administered this year so far compared to the same period last year.

The HSE will continue to monitor the level of influenza across the population in the coming weeks, as well as the control measures in place in hospitals and the community, and will brief me on developments.