Tag: titers

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

How to Avoid Getting Caught up in a Measles Outbreak

By now, you have likely heard the news that we are on track for record-breaking numbers of measles cases this year, both in the United States and around the world.

You may also have heard that some of the folks getting caught up in these outbreaks weren’t actually anti-vaccine, but were people who thought they already had measles or thought they were already vaccinated and protected.

How to Avoid Getting Caught up in a Measles Outbreak

Are you and your family protected against measles?

Six ways to avoid measles.

You might be thinking, “of course we are, we get all of our vaccines!”

But you still might want to double check, keeping in mind that:

  • only people born before 1957 are thought to have natural immunity to measles, because measles was very common in the pre-vaccine era
  • the original measles vaccine that was used between 1963 and 1967 was not thought to be effective, so if that’s the only dose you had, it should be repeated
  • a recommendation for a second dose of MMR didn’t come until 1990, so many people born before that time have only had one dose, especially since there was never a catch-up program to make sure older people had two doses. Even now, adults don’t necessarily need two doses of MMR unless they are in a high-risk group (foreign travel, healthcare workers, living with someone who has a compromised immune system, people with HIV, and students).
  • children don’t routinely get their first dose of MMR until they are 12 to 15 months old (one dose is 93% effective at preventing measles), with a second dose at age 4 to 6 years (two doses are 97% effective)
  • a third dose of MMR isn’t typically recommended for measles protection

Still think you and your family are protected?

In addition to routine recommendations, to avoid measles in a more high risk setting (traveling out of the country or during an outbreak), you should:

  • get infants an early MMR, giving them their first dose any time between 6 and 11 months of age (repeating this dose at age 12 to 15 months)
  • get toddlers and preschoolers an early second dose of MMR, giving them their second dose at least 28 days after the routine first dose that they received when they were 12 to 15 months old, instead of waiting until they are 4 to 6 years
  • get older children and adults two doses of MMR if they haven’t already had both doses

What if your baby is exposed to measles before you have a chance to get him vaccinated?

Younger infants who are less than six months old can get a dose of immunoglobulin within 6 days if they are exposed to measles. Older infants, children, and adults can get a dose of MMR within 72 hours if they are not vaccinated and are exposed to someone with measles.

And the very best way to avoid measles is to keep up herd immunity levels of protection in our communities. If everyone is vaccinated and protected, then we won’t have outbreaks and our kids won’t get exposed to measles!

More on Avoiding Measles

Titers for Vaccine vs Natural Immunity

It probably seems like a silly question, but can titers help you tell the difference between vaccine induced vs natural immunity?

After all, you should know if you had the disease naturally or if you had a vaccine, right?

Titers for Vaccine vs Natural Immunity

Still, there might be situations in which you need to know if someone has immunity and you want to know if it was vaccine induced or if they earned their immunity naturally.

Unfortunately, you typically can’t, especially as most vaccines mimic having a natural infection.

In a few situations, if a vaccine targets a very specific part of a virus or bacteria, it may be able possible to tell the difference between vaccine-induced and natural immunity though.

anti-HBs is positive with natural infections and vaccination, but only anti-HBc is positive after a natural infection.

The hepatitis B vaccine, for example, is derived from HBsAg particles, so won’t induce antibodies against hepatitis B core antigen or other hepatitis B proteins.

Most other vaccines, like MMR and Varicella, aren’t so specific. Titers might just show that you are immune, although titer tests aren’t always sensitive enough to pick up vaccine-induced immunity. That’s why, expect for a few high risk situations, titer testing isn’t usually recommended.

More on Titers for Vaccine vs Natural Immunity

What Percentage of Adults Are up to Date on Their Immunizations?

Are you up to date on your vaccines?

What about everyone else?

What Percentage of Adults Are up to Date on Their Immunizations?

Can you guess why this question comes up so often?

Yup.

There is no plan to force adults to get vaccinated...
There is no plan to force adults to get vaccinated…

It’s about herd immunity.

If most adults aren’t immune because they haven’t been vaccinated or don’t get boosters, then since we aren’t seeing that many outbreaks, herd immunity itself must be a myth.

The thing is though, adults were either born in the pre-vaccine era and likely earned their natural immunity or were born in the vaccine era and are vaccinated and immune.

It is also important to understand that herd immunity is disease specific, so when we talk about herd immunity for measles, it doesn’t matter if everyone has herd immunity levels of protection against hepatitis A or Hib.

And adults do get a few boosters and some vaccines that are only recommended for adults, including the shingles vaccine.

In addition, some vaccines, like Hib and Prevnar, have indirect effects, protecting adults even though they aren’t vaccinated, because vaccinated kids are less likely to become infectious.

But back to the original question, how many adults are up to date on their immunizations?

“While modest gains occurred in vaccination coverage for pneumococcal, Tdap, hepatitis A (persons with chronic liver conditions), herpes zoster, and HPV vaccination, coverage did not improve for other vaccinations and many adults remained unvaccinated with recommended vaccines. “

Vaccination Coverage Among Adults in the United States, National Health Interview Survey, 2016

While most adults are immune to what were once common childhood diseases, like measles and mumps, because they were either vaccinated or had the disease naturally, many could do better with newer vaccines that weren’t available when they were kids.

More on Adult Vaccination Statistics