Influenza B

Influenza B

Influenza B is a virus that causes a contagious respiratory illness. When it hits, it can cause fever, muscle aches, sore throat, headaches, fatigue, and other symptoms. Each year, influenza B can cause an estimated 3-5 million cases of severe illness worldwide. Seasonal flu activity usually begins in October and can last through May.

Influenza B is rarely fatal. Most people recover within a couple of weeks, although they can be left feeling weak and tired for some time afterward. However, people older than 65, young children, and people with certain medical conditions may be at greater risk for more serious complications.

Influenza B is spread in two ways: direct contact with an infected person through coughing or sneezing, and indirect contact with an infected surface or object, such as door handles, phones, and computer keyboards.


Because influenza B is so contagious, prevention is key. The following precautions can help:

  • Get vaccinated each year. Flu vaccines are available in the fall and can reduce your risk of getting the flu.
  • Sneeze and cough into your elbow or a tissue.
  • Avoid close contact with people who are already sick.
  • Wash your hands often with soap and water for at least 20 seconds. If soap and water are not available, use an alcohol-based hand sanitizer.
  • Avoid touching your eyes, nose, and mouth.
  • Clean and disinfect frequently touched surfaces on a daily basis, especially when someone is ill.


Most people do not need medical treatment for influenza B. But those at greater risk for more serious complications may require antiviral medications. Antiviral medications work best when taken early, preferably within 48 hours of the onset of symptoms.

Be sure to drink plenty of fluids, get plenty of rest, and avoid contact with others while sick. Over-the-counter medications, such as ibuprofen, acetaminophen, and antihistamines, may help with symptoms.