Measles is on the rise again, all around the globe.

Though the number of people affected in the U.S. is still relatively low compared with the countries hardest hit, there are a record number of U.S. measles cases — more than 700, so far, in 2019, according to the CDC — the highest since the disease was eliminated in the U.S. back in 2000.

Measles has been documented in more than a third of states, with large outbreaks in New York and Washington.

And although the majority of people getting the illness now were never vaccinated, the expanding outbreaks have raised new questions about whether some older adults — including many of those born before the mid-1960s — should be revaccinated, along with some younger people uncertain of their immunization status.

According to the Centers for Disease Control and Prevention, people who were vaccinated prior to 1968 with an early version of the vaccine, which was made from an inactivated (killed) virus, “should be revaccinated” with at least one dose of live attenuated measles vaccine.

Today’s recommended vaccine is known as MMR and protects against measles, mumps and rubella.

“This recommendation is intended to protect those who may have received killed measles vaccine, which was available in 1963-1967 and was not effective,” according to this Q & A on measles from the CDC.

Since few people born in the 1960s likely have their vaccination records handy, many may be uncertain as to whether they got the ineffective vaccine or were later vaccinated with the newer version. In addition, women of any age who are considering pregnancy should make sure their MMR vaccinations are up to date, according to the CDC.

If you’re…