But if flu season is guaranteed to come every year, albeit at unpredictable degrees of severity, why does the country end up with vaccine shortages?
For starters, as NBC News reports, the flu vaccine takes months to create and involves technology that dates back to the 1940s. By the time it's known how much of the vaccine will be needed, the supply is already set and the producers can't just make more on demand. On top of that, Americans are somewhat divided on whether they think the flu vaccine is a good idea and have a tendency to not get vaccinated until they're spooked by reports of how severe the season is panning out.
According to a blog post released by Dr. Margaret Hamburg, commissioner of the U.S. Food and Drug Administration, there were 135 million doses of the flu vaccine produced for this season. So far, 128 million of those doses have been distributed. (That doesn't mean they've all been administered, though).
Hamburg noted that while temporary spot shortages are being experienced, people who still want to be vaccinated can visit Flu.gov and click on the “Flu Vaccine Finder” to see a list of locations in their area that might still have the vaccine.
But is it worth still trying to hunt down a vaccine this late in the season?
Thomas Frieden, director of the Centers for Disease Control (CDC), told the Associated Press the answer is yes. According to Frieden, flu season extends through March. Though he said it takes two weeks for the vaccine's protection to kick in, it's especially worth it for older people, those with heart or lung diseases, and younger children to still get vaccinated.
The vaccine has an effectiveness rate of only 62 percent, but Dr. Adam Stracher with Weill Cornell Medical College told CBSNews.com that people shouldn't be put off vaccinating.
"While it may not be 100 percent effective, even in those patients who get the flu after getting the flu vaccine, they tend to have a milder illness than patients who haven't gotten the flu vaccine," Stracher said, per CBS.
People also mistake common reactions to flu shots -- such as fever and body aches -- as the flu itself. But Stracher says that it's impossible for people to get the virus from the vaccine.
And if shortages become severe?
Since 2004, the CDC has maintained a stockpile of flu vaccines for children, in case a crisis situation arises, reports Slate. During the swine flu pandemic of 2009, vaccinations were handed out on an emergency basis. But, Slate notes, with spot shortages of the flu vaccine such as the ones being experienced this season, there is no system to redistribute vaccines that have already been shipped out to different locations.
For those who have already had their flu shots and remain concerned about contracting the flu, there are extra measures you can take that might help keep you healthy this flu season. Frequent hand washing, making sure you're getting enough sleep and taking certain supplements are all advised.