How is measles spread?

Measles is transmitted by droplets from an infected person’s nose or mouth. The virus can live in the airspace where the person has breathed, coughed or sneezed.

According to the Centers for Disease Control and Prevention, someone who is not vaccinated “can catch measles just by being in a room where a person with measles has been, up to two hours after that person is gone.”

How safe and effective is the measles vaccine?

The measles-mumps-rubella vaccine is extremely safe and effective. The vast majority of people who contract measles have not been vaccinated.

It does not cause autism.

If I choose not to vaccinate my child, why should anyone else care?

An unvaccinated child can get the virus and spread it to those who can’t protect themselves. Infants and people with compromised immune systems cannot get vaccines.

Why is this a problem now?

Vaccination rates are down worldwide. Public health officials are fighting back, repeatedly pointing out that medical and scientific evidence confirms that vaccines are safe. Still, dangerous misinformation is proliferating.

“This feels like a very real-world manifestation of what can happen when you’re in an echo chamber,” said The Times’s Michael Gold, who has reported on the recent outbreak.

[Here’s more on what you need to know about measles, including where else in the country it has spread.]