(KMOX) — A record-setting number of measles cases in the United States already this year -- the highest in 25 years -- and it's not just kids who are getting the illness. Adults are among some of the latest to come down with the measles -- leaving some to wonder if the vaccinations they received as a child are still effective. From 1963 till 1989, you needed only one measles vaccine. Since 1989, the vaccine has been part of the MMR vaccine -- with two doses needed -- one at 12 months, then another just before entering school.
"With one dose of the measles vaccine -- or MMR as we call it today -- the success rate is about 93-percent," said Dr. Jared Henrichs, a primary care physician with SSM Health Medical Group. "So 93-percent of the people exposed to the virus won't get it or won't become symptomatic after exposure. The second dose gets protection up to 97 to 98-percent."
So what about adults who are now wondering if they need a second shot or if their one dose is sufficient?
"Any adult born after 1957 should take a look at their vaccination records," Dr. Henrichs tells KMOX. "The two dose schedule changed in 1989, so if you're born after 1989, you've probably had both doses. So really anyone born between 1957 and 1989 needs to look to see how many vaccines they've had."
"If they are in the general public and they are not at a college or in a post-high school educational setting, or in health care, or travelling internationally, one vaccine is considered ok. But if they are in any of those just mentioned circumstances, they really should have that second vaccine. And if anybody is concerned or has questions or doesn't know, repeating a vaccine series is definitely safe." Dr. Henrichs says there are a couple of reasons for the recent mushrooming of measles cases.
"One is that there are a couple of outbreaks worldwide, specifically Israel, the Ukraine and the Philippines," Dr. Henrichs said. "Each has had huge outbreaks recently and so we have seen more travelers from those areas coming to the United States. But we're also seeing a larger number of unvaccinated individuals than we've ever had since the vaccine has really taken off. And that has really opened us up to having a higher number of cases than we've seen before." Part of the reason for the rise in unvaccinated kids in the US is due to the anti-vaccine movement -- which Dr. Henrichs says must continue to be dispelled as false.
"So that has definitely been debunked," Dr Henrichs told KMOX. "For anybody who is interested in this I recommend they read an excellent investigative journalism piece by Brian Deer out of the United Kingdom. This is clearly a false allegation and it's really kind of put us in the spot that we're at today where we are seeing these large outbreaks."
"In the past, before 1963 when we first got the vaccine, we used to see a half million people a year get infected with the measles and about 500 deaths every year. We saw epidemics every couple of years. After the vaccine, we got to a point in 2000 where we about completely eradicated them. But since 2005, we've been seeing records year after year of the measles coming back."
So far this year, the Centers for Disease Control and Prevention reports there have been 695 measles cases in 22 states, including both Missouri and Illinois. And that's in just the first four months of this year. The previous high since 2000 was 667 in 2014, and that was for a full year.