Bracing for ‘Aussie flu’
As flu season looms, immunisation experts are urging people to get the seasonal vaccine, despite its lack of effectiveness in combating a lethal flu outbreak in the Northern Hemisphere winter.
Concerns have been raised after influenza swept through the UK over the 2017/18 winter, killing at least 231 people and rendering thousands ill in hospital.
Nicknamed ‘‘Aussie Flu’’, the life-threatening flu strain A (H3N2) also killed at least 72 people in Australia last winter.
The flu vaccine used last year was not effective against this strain, but authorities have updated this year’s vaccine in an attempt to fight the virus.
‘‘The vaccines arriving in New Zealand for our winter season have a new updated AH3N2 strain in them, which is a better match and we hope that will give better effectiveness,’’ Immunisation Advisory Centre director, Dr Nikki Turner said.
There are four seasonal influenza viruses circulating globally – two strains of influenza A (H1N1 and H3N2), and two strains of influenza B – Yamagata lineage and Victoria lineage.
‘‘This year in New Zealand, the publically-funded influenza vaccine includes all four strains,’’ ESR public health physician Dr Sarah Jefferies said.
The health impact of flu on the country this winter will depend on the uptake of immunisation and good hygiene practices and how the strains which circulate compare to viruses we’ve had previously and virus strains in the vaccine, Jefferies said.
The virus is fast-mutating, yet immunisation and good hygiene were still our best line of defence in preventing an outbreak and spread of the illness, Turner said.
‘‘We know overall that when the vaccine types more closely match the circulating strains the vaccine is likely to be more effective.’’ The vaccine is less effective in older people, infants, and people with a range of underlying chronic conditions, ‘‘so we cannot guarantee that even when they are vaccinated they are well protected,’’ Turner said.
About 400 New Zealanders die from the flu or related complications each year.
Research shows about one in four people may be infected with influenza during a moderate flu season, and the majority of those people may not know they have flu, Jefferies said.
‘‘This is one reason why immunisation is a key line of defence.’’
From April, the seasonal vaccine will be available through family doctors and licensed pharmacies.
The vaccine remains free for pregnant women, older people and those with certain medical conditions.