The December death of a 21-year-old Pennsylvania bodybuilder studying to become a personal trainer serves as a reminder that the young and healthy can die from the flu. A pregnant woman in Tennessee lost her life to the flu earlier this week. She was the fourth person in the state who died from the virus. The other three Tennessee victims were children. They were among the 13 kids to date who have already died from flu-related illness this year, according to the Centers for Disease Control. Young children, pregnant women and the elderly who fall ill with the flu are at higher risk for more severe symptoms and complications.

Officials say the first and most important protection against flu viruses is getting a vaccination. Even when the vaccine is only partially effective, it can still lessen the severity of symptoms. CDC officials also recommend getting a flu shot to protect the children and the elderly that you are going to be around.

CDC researchers found that at least three-quarters of children who died from influenza between 2010 and 2014 had not been vaccinated. The family of bodybuilder Kyler Baughman said they do not think he got a flu shot this year. “I just think he ignored it and thought it’d go away like most people,” his mother Beverly told NBC affiliate WPXI. Baughman’s family is urging others to listen to their bodies. “Whenever you have a fever for multiple days, don’t let it go, get it taken care of,” said his father Todd,

It’s not too late to get a shot.

CDC’s flu forecasters say there’s a 60 percent chance that the greatest incidence will hit by late January. Flu season generally peaks near the end of February. The sooner you get vaccinated, the better. Two weeks after vaccination are usually required for antibodies to build up in the body. The CDC recommend a flu shot for children older than 6 months unless there’s a specific reason why they should not take the vaccine, such as an allergy.

Flu symptoms generally come on quickly and can include:

  • Fever or feeling feverish/chills
  • Cough
  • Sore throat
  • Runny or stuffy nose
  • Muscle or body aches
  • Headaches
  • Fatigue (tiredness)
  • Some people may have vomiting and diarrhea, although this is more common in children than adults.

Even if you do not get a flu shot, you can take steps to avoid getting and spreading the virus. The CDC makes these recommendations:

Avoid close contact.
Avoid close contact with people who are sick. When you are sick, keep your distance from others to protect them from getting sick too.

Stay home when you are sick.
If possible, stay home from work, school, and errands when you are sick. This will help prevent spreading your illness to others.

Clean your hands.
Washing your hands often will help protect you from germs.

Avoid touching your eyes, nose or mouth.
Germs are often spread when a person touches a surface or object that is contaminated with germs and then touches his or her eyes, nose, or mouth.

Clean and disinfect surfaces or objects.
Cleaning and disinfecting surfaces and objects that may be contaminated with germs like the flu can help slow the spread of influenza.

Most people who get influenza will recover in several days to less than two weeks, say CDC officials.