What Is Type B Flu?

January 29, 2020

Clinical Contributors to this Story

Lawrence Grill, M.D. contributes to topics such as Internal Medicine.

This flu season, you may have read news stories about people getting sick from influenza B, and you may wonder how type B flu is different than the typical influenza virus that circulates during flu season.

First, you should know that there are four types of flu virus: A, B, C and D.

  • Type A: If you’ve ever had the flu, it’s likely that you’ve had type A. It usually causes 3 out of 4 cases of illness during flu season.
  • Type B: Can also cause seasonal infections that typically only infect humans.
  • Type C: Usually causes mild infections.
  • Type D: Only affects livestock animals, not humans.

Symptoms of Type B Flu infection

People with type B flu exhibit common influenza symptoms that are also seen with type A, including:

  • fever
  • coughing
  • sore throat
  • body aches
  • headache
  • fatigue

“In adults, it’s generally not as severe as one of the A’s,” says Lawrence Grill, M.D., an internal medicine doctor with Hackensack Meridian Health Medical Group. “It’s generally a milder illness, but it can still produce serious illness in people, and you can still give it to someone else, as well.”

What’s the difference between Type A and Type B Flu?

Influenza B almost exclusively infects humans and is less common than Type A. However, children may be affected more severely if they get type B flu.

“It is felt that most adults have built up immunity to some of the influenza B’s, and children less often do that,” Dr. Grill says. “Children, of course, have had fewer years to acquire immunity, so that makes them particularly susceptible to B.”

It’s important to remember that both influenza A and B are very contagious and can cause the same type of illness and symptoms, regardless of age.

Diagnosis and treatment

See your doctor if you think that you have the flu. And if your child exhibits flu-like symptoms, take them to the pediatrician early to try to catch the illness before it becomes serious.

Doctors can do an in-office test to see if you have the flu. If it’s early in the illness, your doctor may prescribe medication which may shorten the amount of time that you’re sick.

“Even if the test is negative and it sounds like flu, we’ll usually treat you,” Dr. Grill says. “The treatment is generally very well tolerated.”

Whether you have type A or type B flu, your treatment and the length of your illness should be about the same. While you have the flu, stay home and focus on your recovery.

“Take in a lot of fluids, take something for fever and rest,” Dr. Grill says.

How you can avoid getting the flu

The best way to reduce your risk of getting the flu – whether type A or type B – is by getting a flu shot. Everyone 6 months and older should get a flu vaccine annually.

Each year, the flu vaccine is updated to protect against different types of flu virus which research suggests may be common that flu season. This year, the vaccine protects against two type A viruses and one type B virus.

“The vaccine is not a perfect match this year, but it’s still very important to get the vaccine,” Dr. Grill says. “No matter how good the match, you’re still going to do better having the vaccine than you will without it. If it doesn’t prevent the flu, it’ll make it milder.”

Other steps that you can take to lower your risk of getting the flu include:

  • avoiding close contact with people who are sick
  • cleaning counters, doorknobs and other communal surfaces in your home
  • washing your hands often

Dr. Grill is a part of Hackensack Meridian Health Medical Group, a network of over 1,000 physicians and advanced providers at more than 300 practice locations throughout New Jersey. To find a doctor near you, visit HMHMedicalGroup.org.

The material provided through HealthU is intended to be used as general information only and should not replace the advice of your physician. Always consult your physician for individual care.