An outbreak of H3N2 flu in India has left at least two people dead, according to health officials in the country. The virus is known for causing severe illness in young children and older adults. So it’s only normal to wonder what exactly H3N2 is, and what you can do to protect yourself from the swine flu variation.
Health experts in India are calling for people to wear masks, practice careful hand hygiene, and get a flu shot if they haven’t already. While the current outbreak is happening across the globe, it’s captured the attention of people outside of the country given how easily infectious diseases can spread. The H3N2 strain “tends to be particularly hard on vulnerable populations,” says infectious disease expert Amesh A. Adalja, M.D., senior scholar at the Johns Hopkins Center for Health Security.
That said, flu season in the U.S. is currently wrapping up—the Centers for Disease Control and Prevention (CDC) notes that seasonal flu activity is low across the country, although the most frequently reported flu cases were H3N2. According to CDC estimates, there have been at least 26 million flu illnesses, 290, hospitalizations, and 18,000 deaths from flu this season so far.
Sure, with everything we’ve been through over the past three years, it’s understandable to feel a little nervous when you hear about an outbreak. So, do you need to worry about H3N2 in the U.S.? Here’s the deal.
What is H3N2?
In general, H3N2 is a strain of the flu that you want to avoid, if possible. But experts point out that the U.S. just faced a flu season with H3N2.
H3N2 flu viruses began circulating in people in 1968, according to Penn Medicine, and have evolved in the decades since. While H3N2 viruses tend to hit vulnerable populations hard, anyone can get it.
“When you have seasons that are dominated by H3N2, you tend to see more flu-related deaths,” Dr. Adalja says.
“H3N2 is a strain of seasonal flu—it has been the dominant strain in this year’s influenza season, including in the U.S.,” Dr. Adalja says. “India just appears to be having a later peak than in the U.S.—H3N2 already came and went in the U.S. flu season.”
Should you be worried about H3N2?
Dr. Adalja says it’s unlikely we’ll see H3N2 again this season, despite how rapidly it’s spreading in India. “People have immunity because of exposure” from this season, Dr. Adalja points out. With flu season coming to an end in the U.S., it’s also unlikely that H3N2 would double back, he says.
Consider this, too, per Dr. Adalja: H3N2 was one of the strains included in the flu shot. So, if you got your flu vaccine, you should be covered.
Given that H3N2—which is a form of influenza A—was the dominant strain of the flu in the U.S. this season, there is a chance that we could see a “little bump” in flu cases caused by influenza B before flu season wraps up, says Thomas Russo, M.D., a professor and the chief of infectious diseases at the University at Buffalo in New York. “There’s a tendency to have B rear its ugly head later in the season,” he explains.
Symptoms of H3N2 tend to be the same as other forms of the flu. According to the CDC, those can include:
- fever or feeling feverish
- sore throat
- runny or stuffy nose
- muscle or body aches
- Vomiting and diarrhea (more common in children than adults)
How is H3N2 treated?
H3N2 is treated the same way as other strains of the flu, Dr. Adalja says. That means it may be treated by one of four anti-viral medications approved by the Food and Drug Administration for flu:
- oseltamivir phosphate (Tamiflu)
- zanamivir (Relenza)
- peramivir (Rapivab)
- baloxavir marboxil (Xofluza)
How to protect yourself against the H3N2 flu
It’s best to get your flu shot in the fall or even early winter, Dr. Adalja says (at this point, it’s likely you’ve been exposed to the flu—and, again, the threat has mostly passed).
It’s also a good idea to keep following common sense flu prevention guidelines, like practicing good hand hygiene (knowing how to wash your hands) and doing your best to stay away from people who are coughing and sneezing, says William Schaffner, M.D., an infectious disease specialist and professor at the Vanderbilt University School of Medicine. If you do happen to come down with the flu, call your doctor. “You can still get treated with an antiviral medication,” he says.
Dr. Russo emphasizes the importance of good hand hygiene, regardless of the season. “It’s a good thing to do year-round to minimize the risk you’ll get infected with myriad infectious agents we have,” he says. “When winter is gone, we have all our summer viruses. Hand hygiene is always a good strategy.”
Korin Miller is a freelance writer specializing in general wellness, sexual health and relationships, and lifestyle trends, with work appearing in Men’s Health, Women’s Health, Self, Glamour, and more. She has a master’s degree from American University, lives by the beach, and hopes to own a teacup pig and taco truck one day.