Measles have made a comeback in the United States and Europe.
Some medical professionals say the pop-up of the disease is partly due to those not staying up to date on vaccinations.
"What has happened in the U.S. as well as Europe is the recent controversy over the safety of vaccines - MMR, measles, mumps and rubella vaccines - with respect to the false rumor that it's associated with autism," Albert Gros, the chief medical officer at St. David’s South Austin Medical Center, said.
According to him, the rumors have caused people to stop vaccinating their children.
A "heard immunity," is when 95 percent of the community is vaccinated against a disease. It protects others from contracting it, but Dr. Gros said when the percentage is lowered, an outbreak can occur.
"Since it's so highly contagious, all it takes it a few people who are not vaccinated to get the chain of infection started," he said.
Gros said it's about weighing the options.
He says some vaccines for diseases like smallpox are nearly eradicated and aren't as urgent.
"There are risks associated with the vaccine, just like there are risks associated with the disease. I think the risks associated with the vaccine [are] extremely small, close to 1 in a million. The incidents of encephalitis or pneumonia are higher than that," Gros said.
Dr. Gros said he doesn't recommend the vaccine for those whose immune systems are compromised, including kids with certain genetic diseases or undergoing cancer treatments.
For more information about the risks consult the child's pediatrician.