It wasn't easy to tell a 78-year-old man with a double bypass he couldn't have a flu shot.
Normally, he'd be the ideal candidate.
But this was different. This was 2009, and there was a shortage of vaccines for H1N1.
“We were doing big clinics at the local high schools and other places where we were doing thousands of people,” said David Legg, a public health nurse at the Oklahoma City-County Health Department. “It was just one flu shot after another.”
The swine flu outbreak in 2009 is the most recent example of a flu pandemic, a situation where an epidemic is affecting much of the world and crossing international boundaries.
This year's season hasn't reached such proportions, but the nation is experiencing its earliest regular flu season in about a decade, since the 2003-04 flu season.
There have been four flu pandemics since 1918, each with their own characteristics, according to the U.S. Department of Health & Human Services.
In 1918, many Americans lived their entire lives without visiting a doctor, according to the U.S. Department of Health and Human Services. Attitudes toward health care were beginning to change, though, and many doctors would make house calls, according to HHS.
State officials reported the presence of the flu in Tulsa and Clinton in September. Although the number of real cases is probably much higher, there were 2,456 cases of flu reported.
For example, the Red Cross opened an emergency hospital in Tulsa and admitted 200 residents; at least 20 people died. An estimated 50 million people died worldwide, including 675,000 in the U.S. The current-day population of Oklahoma City is about 592,000.
And after about 94 years, scientists and researchers still aren't sure what made that particular flu strain worse than the rest of them, said Gillian Air, a professor of biochemistry and molecular biology at the University of Oklahoma College of Medicine.
Scientists at the Centers for Disease Control and Prevention have been able to recreate the virus, but it's still not clear what features it had that made it so deadly, she said.
Air, who has studied the flu for the past 35 years, said part of the problem in 1918 was there were no antibiotics, and there were problems with secondary bacteria in hospitals.
“The history says that people were dead within hours of showing symptoms,” she said.
One of the worst nights of Dr. Boyd Shook's medical career was in February in the late 1960s.
It was the night he lost five patients to the flu. That February, he made an average of 10 house calls a night.
“The treatment was aspirin and ice water, and you try to keep their temperature down,” Shook said. “That's basically all we could do. Some of them we gave penicillin to, but unless they had clear cut pneumonia, there was no reason to give them penicillin.”
About 10 years before, a pandemic in 1957 and 1958 killed about 70,000 people in the U.S. Shook graduated medical school in 1957. His class was one of the first medical student groups to get the flu shot.
“At that time when you received a flu vaccine, you typically got sick for a few days, so there was not a whole lot of enthusiasm about the flu vaccine because it was almost as bad as having the flu,” Shook said.
This is not the case for the present-day flu shot. Because of how the current flu shot is made, it is not possible to contract the virus from the shot.
“The side effects of the vaccine have been virtually eliminated,” Shook said. “They really have a very, very pure vaccine that's extremely safe, and even though you might feel a little bit draggy the day you get your shot, you usually don't feel anything. The concept that you can get the flu from this vaccine clearly is not true any more.”
It goes against everything you're taught in public health to turn people away who want to get their flu shot, said Joyce Lopez, program administrator for immunizations at the Oklahoma City-County Health Department.
But that's exactly the predicament many health departments experienced in 2009. In the spring of 2009, a new flu virus spread quickly throughout the United States and the world, according to the Centers for Disease Control and Prevention.
The first U.S. case of H1N1, or swine flu, was diagnosed was diagnosed on April 15, 2009, according to the CDC. About a week later, the CDC was working to develop a vaccine for the new virus. Soon, the U.S. government declared H1N1 a public health emergency.
The flu shot that year did not cover H1N1. This meant government agencies and vaccine companies had to work quickly to find another vaccine.
The flu virus is constantly mutating — the reason a new flu shot is needed each year. Scientists typically base what strains to include in the flu shot on what strains are found in places such as Australia, which experiences its flu season opposite of the U.S.
The flu vaccine is made using eggs in laboratories, and it can take several months to create. Thankfully, by November 2009, 61 million vaccine doses were ready, according to CDC.
But at first, Lopez and other public health workers were limited in what they could dole out during flu clinics at local high schools and colleges.
“You would think that we were Buy For Less giving away iPads or something because people would be literally camped out waiting for a shot,” Lopez said. “And you hated to tell them, ‘I'm sorry, but you don't have a pre-existing medical condition, and we have to see all these people that have pre-existing medical conditions, that are pregnant, before we can give you a flu shot.”
Turning healthy people away from getting their flu shots is not typically what county health departments do. Rather, public health entities are generally the biggest proponents of vaccinations and immunizations.
That flu season in 2009 was the only time Lopez has worked a flu pandemic.
“It didn't make sense,” Lopez said. “It was totally against everything that public health is, especially in a pandemic, that's our job to cover everybody.”