The Center for Disease Control suggests that you follow these steps to help prevent your sons from getting sick with the flu. They suggest that these steps should be followed ALL the time and not only during the flu season.
Remind them to not share food, drinks, pens, or pencils with their classmates/friends.
Encourage your sons to cover their mouth and nose with a tissue when they cough or sneeze. Also, provide them with easy access to tissues and running water and soap or alcohol-based hand cleaners.
Remind them to cover their coughs or sneezes using their elbow instead of their hand when a tissue is not available.
Remind them to keep their hands away from their mouth, nose, and eyes.
Remind your sons to practice good hand hygiene and try to provide them with a small bottle of germ killing hand soap that they can keep in their backpack.
Sick students should not come to school and they should stay at home until at least 24 hours after they no longer have a fever or signs of a fever (without the use of fever-reducing medicine).
Clean surfaces and items that are more likely to have frequent hand contact with cleaning agents that are germ killing in nature.