A flu vaccine expert is calling for new vaccines and strategies to combat influenza after her research group found New Zealand's current vaccine protected no more than half of those who had it.
Dr Nikki Turner, the director of the Immunisation Advisory Centre at Auckland University, wants children to have access to one of the new nasal spray influenza vaccines now in use in Britain and the United States.
"I think it would be really important if New Zealand could get this vaccine," she said.
"What we've shown from the Shivers study [Southern Hemisphere Influenza, Vaccine Effectiveness, Research and Surveillance] is that we've got a really high burden of disease in New Zealand, higher than we thought we did, particularly in children.
"I would be really keen to access and use this vaccine in New Zealand for children."
A Shivers paper, published last month in the international journal Vaccine, estimated 2012 flu vaccine effectiveness among Auckland City and Middlemore Hospital respiratory infection patients to be 39 per cent overall - 59 per cent for those aged 45-64, but just 8 per cent for the elderly.
A study of last year's seasonal vaccine estimated its effectiveness at 50 per cent among hospital and general practice patients in central, south and east Auckland.
"We know flu vaccine effectiveness varies from year to year," said Dr Turner. "Our results are in line with other countries' results."
She said overseas studies had shown flu vaccines were less effective in the elderly, although the 2012 Shivers results on the elderly were not statistically significant because there were few elderly hospital patients in the study.
Protecting the elderly is a key aim of the Government's vaccination strategy, under which annual flu shots are state-funded for the elderly, for those with a range of chronic illnesses, pregnant women and children between 6 months and 5 years with a history of respiratory illness.
Dr Turner said greater protection of the elderly and others at high risk from the flu was needed by vaccinating those around them to stop flu spreading to them. Children were the biggest spreaders of the flu.
The nasal spray vaccine now being used in the US and Britain - FluMist and Fluenz - uses live, weakened, influenza viruses, unlike the flu injections used here, which contain fragments of killed viruses.
Dr Turner, a member of Pharmac's immunisation subcommittee, said the live, weakened-virus vaccine worked better than killed-virus versions in children because their immune systems had been exposed to flu viruses less than in older people.
Virologist Dr Lance Jennings said that despite the known weaknesses of flu vaccination in the elderly, "it's better than nothing". He urged investigation of high-dose vaccines for the elderly, and efforts to increase vaccination rates, especially among health workers and others in contact with the elderly.
A Medsafe spokesman said it had not had a licensing application for FluMist/Fluenz, but it had received one for the Novac-S brand of live, attenuated nasal flu vaccine powder.
Pharmac operations director Sarah Fitt said, "In the case of a very widely used product like influenza vaccine, we would want to have a product ... registered by Medsafe before we considered it for funding."
Flu jab effectiveness
39% among respiratory infection patients in hospital
50% among hospital and GP patients
Source: Estimates from two studies in Auckland