Influenza Virus B is the worst of the Flu Viruses especially in the elderly and young children.
The Influenza Virus that is the most deadly in children and elderly or people with very weak immune system or other health issues is the Influenza B.
Although Influenza A is still bad it's not as bad as the Influenza B.
It's a good idea to get your flu shot to hopefully avoid getting the flu and keep eating healthy and getting plenty of Vitamin C as well as drinking plenty of water and getting plenty of rest to boost your bodies immune system.
When you have a boosted immune system your body can help fight off the flu virus much better.
But if your fever or flu virus doesn't go away within a few weeks or you seem to get worse then go to urgent care or the emergency room.
Especially in toddlers, babies and young children if they have a fever of 100 F or more and it won't go down take them to the emergency room.
A high fever especially in young children, toddlers and babies can possibly cause brain damage.