Our scientific knowledge about flu has advanced a lot since those days. In 1918 doctors didn't even know the disease was caused by a virus, let alone have the ability to make a vaccine against it.
But our current experience with a distant (and, fortunately, much less deadly) relative of that 1918 virus - H1N1, or "swine flu" - shows that our antiquated vaccine-making process wouldn't stand a chance against another killer flu pandemic if it emerges.
Shannon Dames, communicable disease manager for the Deschutes County Health Department, explained that flu pandemics usually occur in three waves. The first wave of the current swine flu pandemic happened back in the spring and early summer of 2009. The second wave - typically the worst in terms of the number of people who get infected - is happening now. In fact, it appears to be already receding.
"We're definitely seeing a leveling off, based on our school absentee rates coming down or at least leveling off, and our hospital admission rates and emergency room visiting rates are definitely coming down," she said.
"Our peak of this was Oct. 22, so we're definitely on the downside of this by any measurement," confirmed Dr. Alan Ertle, Cascade Healthcare Community's incident commander for the H1N1 outbreak. "There are fewer admissions, fewer people in the ICU [Intensive Care Unit], school absentee rates are down."
This is no thanks to the swine flu vaccine, which for the most part hasn't even arrived yet. Last week the Oregon Department of Human Services announced that by Friday, Nov. 13, it expected to have received enough doses to vaccinate only 24 percent of "the priority group" - meaning pregnant women, health care providers and emergency service workers, people with underlying health problems such as asthma or emphysema, and people who are younger than 25 or older than 65.
So three-quarters of those inside the priority group and all those outside it - almost 88 percent of the population - just have to keep waiting for the vaccine.
How long? Nobody knows.
Frustration over the vaccine delay has been aggravated by over-optimistic predictions that officials made during the summer and into the fall.
In late July the Centers for Disease Control announced that "vaccine manufacturers are projecting that as many as 114-115 million doses of influenza vaccine will be available ... and manufacturer projections indicate that the vast majority of vaccine will be distributed by the end of October."
"Over the course of the flu season we are expecting to have a large enough supply to vaccinate everyone with the H1N1 vaccine," Dr. Mel Kohn, public health director for Oregon, assured the public in a news release issued at the end of September.
But by mid-October, DHS was singing a different tune: "According to the CDC, nationwide 40 million doses had been estimated by the end of October, but only about 28 to 30 million doses will be available during that time frame."
And by the end of October it was sounding distinctly pessimistic: "The H1N1 vaccine continues to trickle into the state. So far, Oregon has received about 6 percent of the vaccine necessary for the people in priority groups, which accounts for about half of Oregon's population."
"It's definitely not going how we expected. ... It's been really challenging to be really transparent about how much vaccine we have," Dames said. "People get frustrated when they hear we have vaccine and they're not able to get it. We were hoping that [waiting] period would be a couple of weeks, and it's now drawing out to where it could be a couple of months."
What's causing the hold-up? The main reason is reliance on a vaccine-making technology that's more than 50 years old.
It involves injecting live flu virus into fertilized chicken eggs, where it multiplies before it's extracted, killed and put into a vaccine formulation.
The bureaucratic process is time-consuming too. "It takes approximately five to six months for the first supplies of approved vaccine to become available once a new strain of influenza virus with pandemic potential is identified and isolated," according to the World Health Organization. "These months are needed because the process of producing a new vaccine involves many sequential steps" - WHO identifies 10 of them - "and each of these steps requires a certain amount of time to complete."
To make matters worse, it turned out that the current strain of H1N1 grows more slowly in chicken eggs than most other types of flu virus. And the drug companies that supply vaccine to the United States (there are just six of them, and only one has a facility in this country) were hard-pressed to produce enough vaccine for both H1N1 and the garden-variety seasonal flu.
(Ironically, fear of swine flu has increased the demand for seasonal flu vaccine, which has led to shortages of that too.)
An alternative technology that could produce large amounts of flu vaccine more quickly involves incubating the virus in cultures of animal cells. This technology has been around for a long time - it was used to produce the first polio vaccine - but most flu vaccine makers have been reluctant to invest in it, and the US Food and Drug Administration has been reluctant to approve it.
Although the federal government has spread more than a billion dollars around to encourage drug companies to develop cell-culture facilities in the US, only one - Novartis - currently has plans to build one. (Novartis recently got approval from the German government to market the first cell-cultured swine flu vaccine, called Celtura. The vaccine has not yet been submitted to the FDA for testing and approval in this country.)
Local health officials say that even if swine flu vaccine doesn't become available until the current wave is over, it's still important to get a shot to avoid catching it during the third wave, which is expected to strike in the spring.
How bad will the third wave be? Judging from past experience with pandemics, it shouldn't infect nearly as many people as the second wave. But this strain of flu already has behaved in some peculiar ways, and there's no way of predicting what it actually will do.
For one thing, the current swine flu - unlike most flus, but disturbingly like its deadly 1918 predecessor - seems to strike hardest at young, healthy people instead of the very old and very young.
In a normal flu season, most deaths occur among people over 80.
But according to a report by the CDC in mid-October, 90 percent of Americans killed by the swine flu up to that point were under the age of 65, and more than half of those who had been hospitalized were under 25.
Another worrisome characteristic is that this strain of swine flu seems to be unusually contagious. "The attack rate - meaning the likelihood that you'll get the flu if you're exposed to it - is much higher than seasonal flu, in the 40 percent range, so you have a lot more people getting sick from it," Ertle said. "Is it worse than seasonal flu in terms of causing complications? Offhand I don't get that impression."
But the odds are that the more people catch the flu, the more will develop complications and need hospitalization. Ertle estimates that St. Charles in Bend has admitted about 120 people with the flu during the current wave.
Linda Olsen, a veteran Intensive Care Unit nurse at St. Charles, said that at the flu's peak the 17 beds in the ICU weren't enough to accommodate flu patients plus those with other illnesses. The hospital had to cancel all elective surgeries one day because there weren't enough ICU beds available for post-operative patients.
Contrary to Ertle's impression, Olsen said the current swine flu appears to make people sicker than typical seasonal flus. "Even though they say it's no worse than other flus, we're seeing people come in who are very, very sick and some who are even dying," she said.
Probably the most troubling prospect is that between the end of the second wave and the start of the third, the H1N1 virus could change into a new and more dangerous form.
"The uncertainty around the third wave is that by that time the virus has had more time to mutate," Dames said. "So sometimes as the virus gets 'smarter' you can see higher mortality rates - there's a risk we might see a more severe strain. But there's absolutely no way to know that."
"That's the problem," Ertle agreed. "Because you have the H1N1 flu out there and also the seasonal flu, you have the whole possibility of an antigenic shift - a mixing of flu strains together."
In the meantime, there's not much people can do except follow the by-now-familiar precautions - washing hands frequently, covering coughs and sneezes, staying home if they're sick - and hope the vaccine makers don't run out of eggs.
If you experience these severe symptoms,
emergency medical attention is recommended.
Painful pressure in chest
Severe or Persistent vomiting
Flu-like symptoms improve but then return
with fever and worse cough