Health officials have asked students and staff potentially exposed to the virus and who either have not been vaccinated or cannot verify immunity to stay home.

There are now more cases of measles in America than in any year since the disease was eradicated nearly 20 years ago.

The agency also shares preliminary results of an Ebola vaccine trial showing that it is 97.5 percent effective at protecting from infection.

So far this year, 465 infections have been reported, with numbers approaching their highest since measles returned to the country.

Most people who contracted the disease were unvaccinated and some state legislatures are now considering whether to curtail nonmedical vaccine exemptions.

Only a handful of contagious cancers are known to exist, yet they have attracted an increasing number of researchers worldwide trying to understand how and why they arise.

After attacks on two Ebola treatment centers in Democratic Republic of Congo last week, Doctors Without Borders says public health workers are “failing” to control the epidemic.

The outbreak has infected 50,000 people and killed 300, most of them children, since cases began to crop up in October 2018.

Most of the 34 patients are under 10 years old, and almost all have been confirmed as unvaccinated against the virus.