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Whenevernews of a measles outbreakhits, its totally valid to wonder about your own susceptibility to the virus.

arm with bandaid after measles booster vaccine

Liudmila Chernetska/Getty Images

Sixteen people have been hospitalized.

This…shouldnt be happening.

In 2000, measles wasofficially eliminated from the United States, thanks to widespread, effective vaccination.

But, as weve seen more and more, the virus still pops up from time to time.

We asked infectious disease experts to share everything you oughta know.

First, heres how the measles vaccine works.

(Theres also an option that includes chickenpox, or varicella.)

This can trigger few (if any) symptoms before your body eradicates the viruses.

The MMR vaccine should have been baked into yourchildhood immunization schedule.

So its possible to reach adulthood without ever receiving it, he notes.

Can measles immunity wane over time?

As a vaccine, its super effective, Dr. Moody tells SELF.

We think that once youve got immunity, it probably does last for the rest of your life.

But there are some potential reasons immunity may weaken a tad over time.

Now that we dont have as much measles circulating in the country, that might not happen.

Also, immune function in general declines with age, Dr. Moody says.

Can you test for measles immunity?

In short, yes.

Anantibody titer testis a blood test that can check your immunity to the measles virus.

However, Dr. Moody notes that antibodies are only one part of the picture.

We dont really think the antibodies themselves are protecting you against measles, he says.

Its probably a T-cell response.

T-cells are white blood cells that fight germs and protect you from disease.

So yes, you could go and get a measles antibody test.

But its sometimes easier to just get the vaccine and be done with it, says Dr. Moody.

(Again, immunity isnt a perfect science!)

That said, it is important to be sure youre fully vaccinated.

The safest course is to get two doses, Dr. Russo says.

Everybody has to judge their own risk personally and talk to their physician about it, Dr. Moody says.

Is a booster necessary for most people?

Theyre very effective and very, very safe.