‘Tis the season for chilly nights, end-of-year celebrations and….the flu. While the flu season varies a little from year to year, the CDC estimates that the flu affects up to 1 in 5 Americans a year, and it’s responsible for up to 200,000 hospitalizations — not to mention plenty of sneezing, coughing and misery.
But despite its prevalence, there are plenty of lingering myths about what’s happening during the flu, and the best ways to treat and prevent it. Read on to learn the science behind this pesky virus—and why getting the flu vaccine is the best way to coast through this year’s flu season unharmed.
What exactly causes the flu, anyway?
Contrary to rumor, the flu is caused by a virus, not by bacteria (which is why antibiotics won’t treat it). Unlike bacteria, which are living cells all on their own, viruses aren’t made up of cells. Instead, viruses “live” by entering their host and hijacking the host’s cells to generate more of the virus. Those newly-created viruses go on to infect more host cells, setting off a cascade that eventually causes the flu symptoms you know (and decidedly do not love).
The influenza virus is a respiratory virus, which means that it affects the cells that line your respiratory tract—your throat and airways. That’s why you might notice a sore throat as one of the earliest flu symptoms, and develop a cough that lasts during and even after your flu.
As for how you get the flu in the first place, it spreads by two major pathways. One is airborne: an infected person coughs or sneezes and the flu virus flies through the air, ultimately landing on you. The second way is by touching an infected surface then touching your nose and mouth. The flu virus may survive for longer in cold, dry weather, which is why flu season in the US generally runs from October to March (while people in the southern hemisphere have their flu season from June to September, during their winter).
Fighting back against the flu
While the flu virus has a head start in infecting your respiratory tract, your immune system soon starts to fight back. Your immune cells create proteins, called antibodies, that can identify and attach to the outer coat of the virus, targeting those viral particles for destruction. Within a day or two of the initial infection, your body starts fighting back hard against the virus, which is part of why the flu often comes with fatigue, sluggishness and general malaise.
That immune response causes another symptom: a fever. While the fever isn’t comfortable, it is helpful for fighting off the flu. A slightly higher body temp helps certain immune cells work more efficiently, so they can target and kill the flu virus more quickly.
However, a fever can affect other tissues in your body, too. So while a fever of up to 100.5 to 101 degrees may not pose a serious risk to otherwise healthy people, a higher fever may require medical attention to avoid complications.
Prevention is your best defense
The absolute best way to prevent the flu is to get vaccinated. Each year, scientists create a vaccine against the top three or four strains of flu virus most likely to affect us, based on the flu strains going around during flu season in the southern hemisphere—which occurs during our spring and summer. The vaccine, made up from inactivated virus, gives your body a head start on producing antibodies against the flu virus, so you can start fighting the flu right away—before you develop symptoms.
Aside from immunization, your best defense against the flu is to wash your hands regularly and thoroughly, also avoid touching your mouth and face. While the flu can spread via the air — say, if someone sneezes next to you on the subway — it’s more likely to spread via contaminated surfaces, like handles and doorknobs.
And, of course, maintaining good general health helps keep your immune system strong and able to fight off infection. Maintaining a healthy sleep schedule, eating right and visiting your doctor for regular check-ups all contribute to your overall health, so you can fight off (and bounce back from) the flu in no time.