Tag: third dose of MMR

Why Are Vaccinated Australians Now Catching Measles?

Measles is on the rise in Australia, like many other places. But why are vaccinated Australians now catching measles?

More vaccinated Australians are catching measles because there is more measles in Australia.
More vaccinated Australians are catching measles because there is more measles in Australia.

And has this got folks thinking it is because the disease is evolving?

Why Are Vaccinated Australians Now Catching Measles?

Well, apparently it has some folks thinking that.

Remember, Andrew Wakefield has also been talking about mutant measles.

Is that what this story in Australia was about?

No.

“In recent years, 13 Victorians have been hospitalized with measles despite having one or two vaccinations that should have made them immune. Why? Well, experts believe that because measles is so rare in Australia, we pretty much never come into contact with it, so our immune systems are starting to let their guards down and wane a little bit.”

Nathan Templeton on Measles Immunity Concerns

What is he talking about?

It’s the idea of exogenous boosting from being around natural infections. In other words, after you become immune from being vaccinated, you could get a boost in your immune protection if you are around someone with the disease.

“The exogenous boosting (EB) hypothesis posits that cell-mediated immunity is boosted for individuals reexposed to varicella-zoster virus (VZV).”

Talbird et al on Understanding the role of exogenous boosting in modeling varicella vaccination.

While this is thought to happen with chickenpox, we aren’t sure if it happens with measles.

It might, but the “problem” is that it is known that folks can have an amnestic response, so can be immune even though they have low antibody levels.

Mostly though, it is important to keep in mind that most of the people who get measles are unvaccinated, often intentionally unvaccinated.

“The key to measles elimination is increasing vaccination coverage and monitoring of measles antibody status for all ages, as well as enhancing surveillance of both domestic and overseas incidences.”

Inaida et al on Measles elimination and immunisation: national surveillance trends in Japan, 2008-2015.

So how many vaccinated Australians are getting measles?

Overall, there are 154 cases of measles in Australia so far this year.

“In Australia, the majority of measles cases are due to unvaccinated individuals becoming infected while travelling to countries in which measles is either common or there are outbreaks occurring. As measles is highly contagious, these people can then spread the disease to others, causing outbreaks, often before they are aware that they have the virus.”

Australia’s Measles Outbreaks 2019

And just as in the United States and most other countries, most of their outbreaks are started by folks who are unvaccinated.

More on Measles in Australia

How Do You Know If You Have Measles Immunity?

With all of the measles cases, you might be wondering if you have immunity to measles?

Are you worried that you might get measles?

Should you get a booster dose of MMR?

Or a titer test?

How Do You Know If You Have Measles Immunity?

Fortunately, most of us can feel confident that we do have measles immunity and that we won’t get caught up in any of the ongoing outbreaks.

Why?

If you have had two doses of MMR, then you can be confident that you have measles immunity.
If you have had two doses of MMR, then you can be confident that you have measles immunity.

Because we are vaccinated and protected!

If you haven’t had two doses of MMR (or any measles containing vaccine since 1967), then understand that two doses is your best protection against measles.

Is There a Blood Test for Measles Immunity?

What about titer tests?

While there is a blood or titer test for measles immunity, it isn’t routinely used.

The one situation in which a measles titer test might be useful though, is for those born before 1957 to confirm that they really had measles.

For others considering a titer test in place of vaccination, it is typically better to just get another dose of MMR, but only if you haven’t already had two doses.

Why Was My Measles Titer Negative?

A positive measles titer does mean that you are immune, but what about a negative measles titer?

“For HCP who have 2 documented doses of MMR vaccine or other acceptable evidence of immunity to measles, serologic testing for immunity is not recommended. In the event that a HCP who has 2 documented doses of MMR vaccine is tested serologically and determined to have negative or equivocal measles titer results, it is not recommended that the person receive an additional dose of MMR vaccine. Such persons should be considered to have presumptive evidence of measles immunity. Documented age-appropriate vaccination supersedes the results of subsequent serologic testing.”

Immunization of Health-Care Personnel: Recommendations of the Advisory Committee on Immunization Practices (ACIP)

If you have had two doses of MMR and have a negative measles titer, you don’t need another dose of MMR. You are likely immune, even with that negative titer.

“Most vaccinated persons who appear to lose antibody show an anamnestic immune response upon revaccination, indicating that they are probably still immune.”

Epidemiology and Prevention of Vaccine-Preventable Diseases

And since you would need a second dose if you had a negative titer after having just one shot, you might as well just get the second dose instead of checking your titer.

Do You Need a Measles Booster?

Have you had two doses of MMR?

If so, then you don’t need another dose.

The second dose isn’t technically a booster anyway. It is just for those who might not have responded to their first dose.

And two doses of MMR are about 97% effective at preventing measles.

That’s why most of the people in measles outbreaks are unvaccianted.

Neither primary nor secondary (waning immunity) vaccine failure are common with the measles vaccine.

What’s the biggest issue with the MMR? Folks who are still too scared to get their kids vaccinated and protected!

More on Measles Immunity

When Do You Get the Measles Vaccine?

With the rise in measles cases this year, folks are asking when they routinely get the measles vaccine to help make sure they are vaccinated and protected.

Do you know when you routinely get your measles vaccine?
Adults who aren’t high risk might be able to get away with simply having one dose of MMR or a measles containing vaccine since 1967.

Unfortunately, there isn’t an easy answer.

When Do You Get the Measles Vaccine?

Well, there kind of is.

Today, we routinely give:

  • the first dose of the measles vaccine (MMR) when toddlers are 12 to 15 months old, and
  • the second dose of MMR when they are 4 to 6 years old

However, if you are at high risk to get measles, especially if you are planning to travel out of the country or to specific areas with active outbreaks, you should get those doses early.

Early Doses of MMR

How early?

As early as age six months.

In fact, high-risk infants 6 through 11 months of age should receive one early dose of MMR vaccine, a dose that will have to be repeated when they are 12 months old. This early dose is mostly about international travel though and not travel within the United States, unless there is a specific recommendation in a local area.

“For outbreaks with sustained, community-wide transmission affecting infants <12 months of age and with ongoing risk of exposures to infants, health departments may consider vaccination of infants aged 6-11 months in these affected areas (including visitors) with 1 dose of MMR vaccine. This recommendation should be made following careful assessment of the benefit of early protection against measles during a period of increased transmission and exposure, and risk of decreased immune response following subsequent MMR doses in infants vaccinated at <12 months of age compared with infants vaccinated at ≥12 months of age.”

Manual for the Surveillance of Vaccine-Preventable Diseases

And children 1 to 3 years of age who are high-risk should receive two doses of MMR vaccine (instead of waiting to get the second dose when they are 4-6 years old), separated by at least 28 days.

This second dose doesn’t have to be repeated though.

When Did We Use to Give the Measles Vaccine?

Still, more than a review of the current immunization schedule, most folks want to know when we used to get vaccinated against measles. That’s what might help you figure out if you are vaccinated and protected.

Hopefully, you can just check your shot records too.

It might also help to know that we began:

  • giving the first measles vaccine in 1963. This doesn’t count as a dose of measles vaccine though, as it didn’t provide long-lasting protection.
  • giving the first improved, live measles vaccine in 1967.
  • using the combined MMR in 1971.
  • offering a second dose of MMR to kids in 1990.

So, how many doses have you had?

What to Know About Getting an MMR Vaccine

If you haven’t had two doses and are at high risk to get measles, get caught up and protected. Keep in mind that you don’t need to check your titers first and you won’t need a third dose of MMR. Titers might be a good idea if you were born before 1957 and aren’t sure if you had a natural case of measles.

“The best way to protect yourself and your loved ones from measles is by getting vaccinated. You should plan to be fully vaccinated at least 2 weeks before you depart. If your trip is less than 2 weeks away and you’re not protected against measles, you should still get a dose of MMR vaccine.”

Before international travel: Make sure you’re protected against measles

Lastly, if possible, try to get your second dose of MMR at least two weeks before your trip.

More on When We Give the Measles Vaccine

Do You Need Another Dose of the MMR Vaccine?

The measles outbreaks have a lot of people concerned about measles.

And that means measles and vaccines are getting a lot of extra attention.

Unfortunately, getting extra attention doesn’t always translate into getting great advice, especially when it is leading a lot of folks into thinking they need to rush out and get another dose of MMR or to check their titers to make sure they are protected.

Do You Need Another Dose of the MMR Vaccine?

So are you protected against measles?

Have you had two doses of MMR? (Remember, kids typically get their first dose at age 12-15 months and a second dose when they are 4-6 years old, with early doses in high-risk situations.)

If you have documentation of two doses of MMR (or a measles containing vaccine), then you can confidently say that you are protected. No, it’s not 100% protection, but it’s close.

“Documented age-appropriate vaccination supersedes the results of subsequent serologic testing. If a person who has 2 documented doses of measles- or mumps-containing vaccines is tested serologically and is determined to have negative or equivocal measles or mumps titer results, it is not recommended that the person receive an additional dose of MMR vaccine. Such persons should be considered to have presumptive evidence of immunity.”

Prevention of Measles, Rubella, Congenital Rubella Syndrome, and Mumps, 2013: Summary Recommendations of the Advisory Committee on Immunization Practices (ACIP)

If you haven’t had two doses of MMR, then know that two doses are your best protection against measles.

Have you heard that people born before 1989 may need another dose?

What is the significance of the year 1989?

The recommendation to give a routine second dose of MMR started in 1990, so folks born much before then likely only had one dose, unless they were considered high risk and had the second dose before traveling out of the country, starting a healthcare job, or going to college, etc.

Instead of 1989, the typical cutoff year for protection is around 1986, since those kids would have been turning four years old in 1990, so would have gotten their second dose of MMR on schedule. If you were born before 1986, you would have started kindergarten before the recommendation to get a second dose.

The other years that are important are 1963 to 1967, as that’s when the very first measles vaccine was used, a vaccine that was later found to not be very effective. If that is the only time you were vaccinated, then you should be vaccinated again.

What about 1957?

In general, if you were born before 1957, we assume that you had measles because most people had measles back then. Maybe you didn’t though, so in a high-risk situation, like traveling out of the country or in the middle of an outbreak, this could be a good situation to check your measles titer to confirm that you are immune. If you aren’t, then get two doses of MMR.

How many doses of MMR have you had?
How many doses of MMR have you had?

So here are your scenarios:

  • Were you born before 1957? Then you probably had measles, but can check your titers to make sure you are immune, especially if you will be in a high-risk situation, like near an outbreak or traveling.
  • Did you get a dose of measles vaccine between 1963 and 1967? If this was your only dose, then you should get a dose of MMR now.
  • Did you get a measles vaccine between 1968 and 1971, before the MMR became available? That counts as a dose of measles containing vaccine. If that is your only dose, then you might get another dose of MMR, if you will be in a high-risk situation, like near an outbreak or traveling.
  • Have you only had only one dose of MMR or other measles containing vaccine, which is more likely if you were born well before 1990? Then get another dose of MMR if you will be in a high-risk situation, like near an outbreak or traveling.
  • Have you had two doses of MMR vaccine or or other measles containing vaccine (and have your immunization records to prove it)? Then you should be protected. You don’t need to check your titers and you don’t need a third dose of MMR.

What if you aren’t sure? Then get at least one more dose of MMR.

If you don’t think that you were ever vaccinated against measles, then you might get two doses of MMR.

If you aren’t sure, but think that you already were vaccinated, then this would be a good situation to check your titer. Be prepared to get your MMR vaccines again if you are negative though.

Do all adults need two doses of MMR?

Surprisingly no, although that is considered the best protection against measles, there was never a general catch up program for older folks with the recommendation to get a second dose in 1990. So if you have had one dose of MMR and aren’t at any extra risk to get measles – no travel, no nearby outbreaks, and not a health professional, etc., then one dose might be enough… for now.

More on MMR Vaccines