News Briefs – April 2019 – Who Needs a Measles Vaccine During an Outbreak?

News Briefs — Who Needs a Measles Vaccine During an Outbreak?

Paul Offit, MD: Hi, my name is Paul Offit. I’m talking to you today from the Vaccine Education Center at the Children’s Hospital of Philadelphia.

What we’re seeing recently are outbreaks of measles. There was an outbreak recently in Washington state. There was an outbreak in Oregon. There was an outbreak in New York state. There’s been outbreaks in Illinois, New Jersey, and other venues. Even in Pennsylvania recently we’ve had an outbreak of measles.

So, people wonder then are they protected? Now, I’ll start from the beginning. Before there was a measles vaccine, which was first introduced in 1963, every year in this country we’d see between 3 and 4 million cases of measles. We would see 48,000 hospitalizations, and as many as 500 deaths a year.

The first vaccines were introduced in 1963. Now, one of those vaccines was an inactivated virus, which is not the way we make the current vaccines. That inactivated virus was made by taking measles virus, growing it up and then killing it with a chemical so that it couldn’t reproduce itself.

The current vaccines are not made that way. They’re made by taking the virus and then weakening it – a so called live, attenuated viral vaccine – so that you can induce immunity without causing disease.

So, people are wondering what should they do. The first best vaccine was introduced in 1968 and was recommended for all children. Then in 1991, there was a second-dose recommendation. So, the first does was given between 11 and 15 months of age. The second dose recommendation, which came in 1991, was to be given at 4 to 6 years of age.

So are you protected? Here’s what I would say. If you were born before 1957, the odds are you were naturally infected with measles and you’re protected for the rest of your life; you don’t need a vaccine. If you’ve gotten two doses of the vaccine that was first introduced in 1968, which is to say the live, weakened form of the vaccine and you got it when you should’ve gotten it, at 12 to 15 months of age then again at 4 to 6 years of age, you’re protected. So, you don’t need a third dose.

If you got that inactivated vaccine, which was on the market between 1963 and 1967, and never got the subsequent two doses of vaccines, you are likely not protected and should get then measles-containing vaccines. If you’ve only gotten one dose of measles-containing vaccine, you probably would benefit from getting a second dose.

Now, if you’re going into a region where measles is common, for example Western Europe, measles is common there, there are many parts of the world where measles is still common, and you fall into a category where you need another dose of vaccine, you should get it really at least two weeks before you’re going to that area.

So, we had eliminated measles from this country by the year 2000. Sadly, it’s back mostly because there are parents who are choosing not to vaccine their children. And there are pockets, for example Clark County in Washington state, where enough parents have made that choice that you see the virus coming back.

So again, we have to reconsider whether or not we’re adequately protected. Hopefully that helps.

Thank you.