In a small white consulting room at the Silverdale medical centre, 63-year-old Isobel Singleton bares her shoulder, gazes at the ceiling and tenses, as she does this time every year. It's time for her free flu jab, and nurse Jill Tate slides the slim needle smoothly into Singleton's flesh.
It takes just a second and Singleton is vaccinated against influenza strains carrying such esoteric names as B Wisconsin 1, A California 7 (H1N1) - and the variant that has been wreaking havoc across North America this year, H3N2.
The US Centers for Disease Control and Prevention (CDC) reported 64 children killed by the flu this season. In New York alone, more than 19,000 cases of influenza were reported in the six weeks of the Northern Hemisphere winter.
In New Zealand, Singleton was one of 612,376 people who received a free flu jab courtesy of the government last year - 13 per cent of the population. Because of her respiratory problems, the former dental nurse was entitled to get it free.
For the past nine years she has suffered from asthma and bronchiectasis. Sitting in the La-Z-Boy at her home in Orewa last year, those problems caused a coughing fit so violent that she put her back out.
Singleton says her breathing difficulties "control my life" and have weakened her immune system, putting her in the "at risk" category for influenza. And so Singleton was first in line when medical centres received the 2013 vaccine.
With winter just three months away, the National Influenza Specialist Group aims to have 25 per cent of the population immunised. It is focusing on people who are at risk of being severely affected by the disease.
The Government has budgeted $18 million to provide the vaccine to about 1.07 million people this year: the elderly, pregnant women, and those put at greater risk by conditions such as asthma, diabetes, heart disease and other serious medical conditions.
Other New Zealanders must get the vaccine subsidised by their employers, or reach into their pocket to pay for it. For them, there is an additional question: Is it worth the cash?
In 1918, New Zealand was still shell-shocked by the loss of 18,000 young men in the trenches in Europe. But that year, the country would be hit by something that killed more quickly than any World War I artillery.
The first affected were the soldiers on board the troopship Tahiti, whose convoy had stopped to refuel at Sierra Leone, West Africa, in August 1918. Fever was reported to be raging in the port, and within days, over half of the men on board fell ill. The final death toll exceeded 80.
Between October and December, this country lost 8,600 people to an ensuing flu pandemic. No other event, says the Ministry of Culture and Heritage, has killed so many New Zealanders in such a short time.
Influenza, says Time magazine, is a disease of modernity: the faster people travel around the world, the easier it is for the virus to spread. And as fast as the vaccine is honed, the virus mutates.
In 1957-58, the so-called Asian Flu killed up to 1.5 million people worldwide. The Hong Kong Flu's death toll in 1968-69 was almost as high. And in 2009, despite great leaps in immunology, the H1N1/09 Swine Flu pandemic killed 14,286 people, including 49 in New Zealand.
Last year's epidemic, which resulted in a 100 per cent rise in hospitalisations, was caused by a new H3N2 strain, dubbed A Victoria. The 2012 vaccine provided no protection against A Victoria. National Influenza Centre director Dr Sue Huang says the virus' evolution makes it difficult for experts to predict what the new strain will be, or when it will arrive.
Retired GP, Dr Mike Godfrey, spends most of his day tending to berry trees on his property in Whakamarama, Tauranga. Godfrey, 75, believes nutrients from certain fruits and plants can provide the right recipe for a strong immune system to protect against influenza.
The grandfather-of-nine has not always been a believer of natural medicine. He spent the first 19 years of his career giving patients the flu jab. Then in 1985, his wife fell ill with mercury neurotoxicity, a condition that causes chronic fatigue. No drug on the market could help, so she sought advice from an Indian homeopath.
"He helped her enormously so I started looking at my patients in a different way," says Godfrey, a former director of a Bay of Plenty health clinic.
He is not against pharmaceuticals - he was prescribing clinical drugs until the day he hung up his stethoscope four years ago - but research conducted by the respected Cochrane Collaboration and the CDC has convinced him the flu vaccine is "useless".
Godfrey says the vaccine compromises the immune system. He says tricking our immune system to produce antibodies will backfire and weaken the power of natural immunity.
Godfrey says: "We need to look at what can be done instead of relying on a magic bullet. This comes down to improving the health of individuals." Godfrey says there is no local evidence that shows flu vaccines are effective. There is little data on the effectiveness for people who are considered most at risk. Yet it is those people who receive free vaccinations, Godfrey says.
So the Herald on Sunday asked the National Influenza Specialist Group for New Zealand data on vaccine efficacy. It does not exist, they confirm. However, Godfrey's depiction of the vaccine as "useless" does seem somewhat of a leap.
The meta-analysis by the Cochrane Collaboration, which he cites, cautions against using the flu jab as "a routine public health measure" for healthy, fit adults, but it also finds the flu jab is 75 per cent effective against the World Health Organisation-targeted influenza strains.
The most recent CDC morbidity and mortality report, published this week, acknowledges the vaccine had limited success in combating the H3N2 virus in elderly people, for whom it was only 9 per cent effective. But it also says the vaccine has been "moderately" effective for children and sick adults.
Overall, this season's vaccine has reduced influenza induced doctors' visits by as much as two-thirds in the US. Canterbury virologist Dr Lance Jennings has recently returned from the US, where states such as NewYork have declared a public health emergency as they respond to their worst flu epidemic in a decade. Jennings, a clinical associate professor at Canterbury Health Laboratories, says the disease has spread so widely because people are not immunised against influenza.
"The severe outbreak followed several years of low influenza activity and a high degree of complacency among the population," he says. "The perception was that the pandemic is over and they did not need worry about vaccines any more."
Moderate effectiveness is better than none, Jennings says, and achieving a critical mass of immunised Kiwis reduces the number of hospitalisations and deaths.
"It is not perfect but it is still an effective public health intervention, with a better performance than other interventions such as cervical screening, which we all accept," he says.
The Government spends about $18 million a year on vaccines to protect the at-risk population from influenza. Employers and individuals spend perhaps $10 million on top of that.
Doctors are motivated by the hope of saving some of the estimated 67 lives lost to influenza over the past three years; employers are in part driven by the innumerable days of workplace productivity lost to sick leave.
The investment seems to be helping. Ministry of Health figures show hospital costs for influenza-related admissions dropping from $7.3m in 2010, to $5.3m in 2011, and just $1.5mlast financial year.
Dr Richard Milne, an independent consultant in pharmaceutical economics, says health officials must consider the costs of vaccination, cost savings, effectiveness of vaccination, target groups and the threshold at which the Government is prepared to pay for healthcare.
The Herald on Sunday asked the Ministry of Health for the latest cost-benefit analysis of immunisation against influenza.
The most recent it could provide was from 1996, and that focused on the value to people aged 65 and over. It indicated the Government would pay $7.1mto vaccinate all New Zealanders aged 65-plus and would save $26.75m in direct medical costs - the cost of the ambulance at the bottom of the cliff. The net benefit would work out at $19.65m.
For some government economists, investment in free flu jabs for retirees and pre-schoolers may seem hard to justify. After all, when when a 70-year-old misses his croquet tournament, or a 3-year-old calls in sick at kindergarten, it does not significantly slow the wheels of industry.
New Zealand's youngest and oldest citizens are not our most "productive units".
A wider analysis, though, will reveal significant flow-on effects: Sick elderly people will spread the virus to younger friends and family; sick children will force their parents to stay home to look after them; sick New Zealanders of any age incur a cost to the health system.
Drug-buying agency Pharmac, which took over responsibility for buying and distributing the flu vaccine in 2004, reveals it has commissioned a new cost-benefit analysis from its immunisation subcommit tee. Spokeswoman Jude Urlich says that review, due for completion this month, includes assessing an application from the Ministry of Health to extend free vaccinations to children under 4 years old.
That request has come in the wake of a new study revealing toddlers were among those hardest hit by last year's epidemic. Preliminary findings from the five-year Shivers (Southern Hemisphere Influenza Vaccine Effectiveness Research and Surveillance) study reveals the impact on those aged over 65, or under 4 years. Dr Huang, one of the lead authors, described the hospitalisation rates for those with influenza-related severe respiratory infections as a "surprise".
Heightened surveillance in Auckland and Counties-Manukau district health boards is now helping scientists around the world select the strains to include in subsequent seasons' vaccines.
As the latest flu epidemic in North America tailed off last month, top US health officials testified to the work of scientists around the world in developing new flu vaccines.
Some day soon, they told Congress, scientists might develop a "universal" flu vaccine that would be effective against every mutating strain of the virus.
"It's possible we could have some real leads in this direction in the next five to 10 years," said Food and Drug Administration chief scientist Dr Jesse Goodman. "Nature is very tricky and this is a very crafty virus, so I'd be very hesitant to predict. There's some exciting progress."
Older New Zealanders like Isobel Singleton, struggling for breath and only one winter away from her Super GoldCard, will settle for the best protection they can get today. For those who are old or sick, flu vaccinations are not a subject for debate. They are a matter of life and death. "If I got the flu I could end up in hospital," Singleton says. "I don't have a choice."