Measles cases continue to rise across the country, with outbreaks reported nationwide.
In South Carolina, over 150 unvaccinated schoolchildren are under quarantine after exposure to measles.
The U.S. has confirmed 1,563 cases this year, according to the Centers for Disease Control and Prevention, the highest annual number in over three decades.
"If you talk to people on the ground, including not only in Texas, but other states, they all say the same thing, which is that the numbers are much worse than that. Probably closer to 5,000 cases,"
says Dr. Paul Offit, director of the Vaccine Education Center at the Children's Hospital of Philadelphia.
The true total of measles cases could be even higher than the official number.
Author's summary: Measles cases surge in the U.S.