(KCEN) -- More than a dozen states are experiencing an increase in whooping cough cases.

In Texas, it's now becoming an epidemic. A brutal cough that can last for months. A potentially fatal illness, especially for babies and young children who haven't had a chance to get all their shots yet.

They actually may have spells of apnea where they stop breathing, so 1 to 2 out of 100 infants can actually die from this. 16 states and Washington, D.C. are seeing an increase in cases, compared to this time last year.

More than 2,000 cases so far in Texas alone, claimed the lives of two babies. The state is on course to have its worst whooping cough outbreak in over 50 years.

Officials this week are issuing a health alert, warning Texans that vaccinations are vital, but the effectiveness of the whooping cough vaccine fades, quickly. By age 11, only 7 out of 10 kids are fully protected.

That's why the Centers for Disease Control recommends a booster shot for pre-teens to protect themselves and any babies they could unwittingly infect.

Symptoms of whooping cough typically last 6 to 10 weeks, but may last longer. In young children, three stages can occur.