- Yakobchuk Viacheslav/Rido/Shutterstock
- At least some of the 9.7 million people infected with the flu this season will get the flu again before the year is up. But it probably won’t be from the same strain of influenza virus.
- Influenza viruses come in four main types: A, B, C, and D. This year, the Centers for Disease Control and Prevention has found more cases of type B infections – something that hasn’t happened since 1992.
- If you’ve been infected with type B flu, you’re still susceptible to contracting type A flu and vice versa.
- This article was reviewed by Rod Oskouian, MD, at the Swedish Neuroscience Institute.
- Visit Insider’s homepage for more stories.
The Centers for Disease Control and Prevention estimate that 9.7 million people have fallen prey to the flu so far this season. And it’s likely that some of those unfortunates will get the flu again before the year is up.
Yes, you can get the flu more than once a year
Yes, it’s possible to get the flu more than once a year, or even more than once a season.
The main reason is that there are many different varieties of the flu virus. Influenza viruses come in four main types: A, B, C, and D. And for each type, there are numerous unique subtypes and strains.
For the last 28 years, the most common viruses that infected people each flu season were type A flu viruses. However, this year, the CDC has found more cases of type B infections – something that hasn’t happened since 1992.
If you’ve been infected with type B you’re still susceptible to contracting type A and vice versa because you’ve only built up an immunity to that specific type B, or A, virus that made you sick the first time. In fact, if you’re unlucky and get the flu a second time in the same season or year, it’s unlikely you’ve caught the same strain.
“It’s almost always a different strain,” says Adrian Cotton, MD, chief of medical operations at Loma Linda University Health. “Physicians often see three ‘peaks’ of influenza – two of the ‘A’ and one of the ‘B’ viruses. However, there are probably too many influenza viruses total to count.”
But there’s a silver lining: the more strains you’re exposed to, the stronger your immune system will likely be against the same or similar strains in the future. That’s why flu vaccines are the best weapon against not only avoiding the flu once but multiple times because they contain multiple different substrains of influenza types A and B.
“Overall, the more exposure you have to different strains and the more years of flu shots you have, the better you’ll be able to fight off the variety of flu strains,” Cotton says. That means your symptoms will be less severe than they’d be otherwise.
As for getting the flu during spring or summer months compared to fall and winter – when the flu is in full swing in the northern hemisphere – your chances are low, but it’s not impossible. Cotton says there aren’t necessarily specific times outside the flu season when your chances of contracting the virus are higher.
When you’re infected with the flu multiple times a year
Unfortunately, it’s not uncommon to get the flu more than once a year, Cotton says. If you do get infected twice, it shouldn’t necessarily be a cause for alarm.
“If you get the flu more than once a season, you shouldn’t be worried. Contracting the virus is more related to how much exposure you have had rather than your body’s strength to fight it,” Cotton adds.
Bottom line: Your best bet for guarding yourself against the many strains and types of flu viruses is to get vaccinated for the flu every year.
Related stories about the flu:
- Yes, you can still get the flu after a flu shot
- How to prevent the flu, according to doctors
- Yes, the flu is contagious. Here’s when you’re most likely to spread the virus
- You can’t get the flu from the flu shot, but there are side effects
- How long the flu should last and when you should see a doctor
- The flu vaccine is not 100% effective but you should still get it every year