The flu is dangerous, deadly and spreading in Houston.

There is currently a flu outbreak in almost every state and kids are most at risk.

About a quarter of the kids at Texas Children's right now are there because of the flu, according to Dr. Claire Bocchini, an infectious disease specialist at Texas Children's.

With school back in session this week doctors are expecting to see even more of an uptick.

Eight-month-old Kingston Walker was admitted Sunday night after his mother noticed he was having a hard time breathing.

“About four days ago he started breathing hard,” said Shareeka Smith. “Vomiting, having fever.”

Kingston tested positive for Influenza A, the most common flu strain this season.

“The flu is very dangerous,” warned Bocchini. “It's not your regular virus that gives you a couple days of runny nose.”

Thirteen kids across the United States have already died this season in what Bocchini says is one of the worst in years.

According to the Center for Disease Control, Houston ranked fourth for transmission last week.

Bocchini says most kids pick it up at school or daycare and the virus poses the most risk to them.

“Their lungs, their immune systems are still developing, especially the younger ones, and so they have a lot more complications," said Bocchini.

Doctors say the best prevention is the vaccine regardless of what you may have heard.

“The flu vaccine is getting some bad press this year because in Australia the flu vaccine was only 10 percent effective for one particular type of flu, it was about 30% effective overall though," said Bocchini.

Bocchini says in the United States it appears the vaccine is 40 to 60 percent effective. And that even if it's not, it still protects children from complications of the flu like being hospitalized or death.

Bocchini recommends that caretakers call a doctor is children have a fever, begin vomiting or have difficulty breathing. Preventative measures include washing hands, staying home if you're sick and getting the flu vaccine.

“Get vaccinated now,” said Bocchini. “It's not too late. we still have a lot of the season ahead of us.”

The flu is so widespread this year that some pharmacies are running out of Tamiflu, which helps prevent and shorten the virus.

Dr. Bocchini recommends that anyone who has been prescribed the medicine may have to be proactive to find it and should ask their doctor's office to help.