Tag: titers

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

Everything You Need to Know About the Measles Vaccine

The measles vaccine is one of the most effective vaccines we have.

It is also one of the safest, having very few serious side effects.

Everything You Need to Know About the Measles Vaccine

So why are some parents still afraid to allow their kids to get vaccinated and protected, putting them at risk to get measles, a life-threatening disease?

“Existing evidence on the safety and effectiveness of MMR vaccine supports current policies of mass immunisation aimed at global measles eradication and in order to reduce morbidity and mortality associated with mumps and rubella.”

Cochrane Systematic Review on Vaccines for measles, mumps and rubella in children

Let’s see if you still are after we get all of your questions about the measles vaccine answered…

Schools in California were closed for at least two weeks in 1917 because of measles epidemics.
Schools in California were closed for at least two weeks in 1917 because of measles epidemics.
  1. How long has the measles vaccine been around? The very first measles vaccine was licensed by John Enders in 1963. An improved measles vaccine was developed by Maurice Hilleman and licensed in 1968, and that is the measles vaccine that we still use today, at least in the United States. It was combined into the MMR vaccine in 1971.
  2. How effective is the measles vaccine? A single dose of the measles vaccine is about 93% effective at preventing a measles infection. Two doses (the second dose was added to the routine immunization schedule in 1994) are up to 97% effective. That’s why almost all of the people who get measles in an outbreak are unvaccinated.
  3. How long does immunity from the measles vaccine last? Immunity from the measles vaccine is thought to be life-long. It is important to understand that the second dose isn’t a booster dose, but is instead for those few folks who don’t respond to the first dose.
  4. Who should get the measles vaccine? Everyone without a true medical contraindication should get the measles vaccine (MMR), with the first dose at 12-15 months and a second dose at 4-6 years.
  5. Can my kids get their measles vaccine early? An advanced immunization schedule is available for kids in an outbreak or if they will be traveling out of the country. The first dose can be given as early as age 6-months, but is repeated when the child is 12 months because of concerns of interference with maternal antibodies. The official second dose can be given early too, as early as 4 weeks after the first dose, as long as the child is at least 12 months old.
  6. Do I need a booster dose of the measles vaccine? People who are fully immunized do not need a booster dose of the MMR vaccine, but it is important to understand whether or not you are really fully immunized to see if you need a second dose. Some adults who are not high risk are considered fully vaccinated with only one dose, while others should have two doses. Are you at high risk to get measles? Do you travel, live in an area where there are measles outbreaks, go to college, or work as a health care professional?
  7. Should I check my measles titers? In general, it is not necessary to check your titers for measles. If you haven’t had two doses of the MMR vaccine, then get a second dose. If you have had two doses of the MMR vaccine, then you are considered protected. Keep in mind that there is no recommendation to get a third dose of MMR for measles protection, although it is sometimes recommended for mumps protection during a mumps outbreak.
  8. If my child gets a rash after getting his MMR, does that mean that he has measles? No. This is a common, very mild vaccine reaction and not a sign of measles.
  9. Can the measles vaccine cause seizures? The MMR vaccine can cause febrile seizures. It is important to remember that without other risk factors, kids who develop febrile seizures after a vaccine are at the same small risk for developing epilepsy as other kids. And know that vaccines aren’t the only cause of febrile seizures. Vaccine-preventable diseases can cause both febrile seizures and more serious non-febrile seizures.
  10. Why do people think that that the measles vaccine is associated with autism? It is well known that this idea originated with Andrew Wakefield, but the real question should be why do some people still think that vaccines are associated with autism after so much evidence has said that they aren’t?
  11. What are the risks of the measles vaccine? Like other vaccines, the MMR vaccine has mild risks or side effects, including fever, rash, and soreness at the injection site. Some more moderate reactions that can rarely occur include febrile seizures, joint pain, and a temporary low platelet count. More serious reactions are even rarer, but can include deafness, long-term seizures, coma, or lowered consciousness, brain damage, and life-threatening allergic reactions.
  12. Why are there so many reports of measles vaccine deaths? There are extremely few deaths after vaccines. The reports of measles vaccine deaths you see on the Internet are just reports to VAERS and are not actually reports that have been proven to be caused by a vaccine. As with other vaccines, the risks from having a vaccine-preventable disease are much greater than the risks of the vaccine. The only reason that it might not seem like that now is because far fewer people get measles now than they did in the pre-vaccine era, when about 500 people died with measles each year.
  13. When did they take mercury out of the measles vaccine? Measles vaccines, including the MMR, have never, ever contained mercury or thimerosal.
  14. Why do we still have outbreaks if we have had a measles vaccine since 1963? In the United States, although the endemic spread of measles was declared eliminated in 2000, many cases are still imported from other countries. As measles cases increase around the world, that is translating to an increase in outbreaks here. Even though overall vaccination rates are good, because there are many pockets of susceptible people in areas that don’t vaccinate their kids, they get hit with outbreaks.
  15. Can we eradicate measles? Because measles is so contagious, the vaccine does have failures, and some folks still don’t get vaccinated, there is some doubt that we can eradicate measles without a better vaccine. That doesn’t mean that the current measles vaccines can’t prevent outbreaks though…

Are you ready to get your kids their MMR vaccine so that they are vaccinated and protected against measles, mumps, and rubella?

If not, what other questions do you have?

While you are thinking, here is a question for you – Do know why they used to call measles a harmless killer?

More on the Everything You Need to Know About the Measles Vaccine

Is a Vaccine Strain Causing The Latest Measles Outbreak?

What’s the first question anti-vaccine folks start asking whenever we see a large outbreak of measles?

No, it’s not how can I get my kids vaccinated and protected so that they don’t get measles…

It is whether or not it a vaccine strain of measles started the outbreak.

That’s not how any of this works…

Where do folks get all of this stuff about genotypes and vaccine strains? I wonder…

Dr. Bob had no facts, but still posted that a vaccine strain of measles could have killed a woman who got caught up in the last measles outbreak in Washington.

Yup.

The usual suspects.

Is a Vaccine Strain Causing The Latest Measles Outbreak?

Why do folks who intentionally don’t vaccinate their kids desperately want these measles outbreaks to be caused by a vaccine strain?

Because then it isn’t their fault that their kids are at risk of getting a life-threatening disease!

It’s never a vaccine strain though.

Remember the Disneyland measles outbreak. A lot of folks were talking about vaccine strains when it first started.

“…California patients were genotyped; all were measles genotype B3, which has caused a large outbreak recently in the Philippines…”

Measles Outbreak — California, Dec 2014–Feb 2015

It wasn’t a vaccine strain.

OutbreaksYearGenotype
Minnesota2017B3
Tennessee2016B3
California2015B3
Florida2013D8
California2014B3, D8
Brooklyn2013D8
North Carolina2013D8
Minnesota2011B3
Washington, Illinois2008D5, D4

For example, during 2011, 222 cases of measles and 17 outbreaks were reported in the United States, with most cases originating from just five countries (France, Italy, Romania, Spain, and Germany). Six different genotypes were identified, including B3, D4, G3, D8, H1, and D9. No vaccine strains…

And no, it doesn’t matter that the vaccine strain of measles, genotype A, differs from all of the wild strains of measles we see in the outbreaks.

“Vaccine induced immunity protects against all virus strains. Measles is considered a monotypic virus despite the genetic variations.”

Factsheet about measles

Unlike the flu, HPV, and pneumococcal bacteria, in which vaccines only protect against different serotypes, in the case of measles, the genotype simply helps us figure out where the measles case came from.

And no, the latest outbreak, wherever it is, wasn’t caused by shedding from a vaccine.

But if it isn’t the vaccine strain, then why do they that is it important to rapidly identify wild strains vs vaccine strains?

“During measles outbreaks, it is important to be able to rapidly distinguish between measles cases and vaccine reactions to avoid unnecessary outbreak response measures such as case isolation and contact investigations.”

Roy et al on Rapid Identification of Measles Virus Vaccine Genotype by Real-Time PCR

That’s easy to answer.

Outbreaks typically trigger a lot of folks to get vaccinated. While that’s great, one possible problem is that some of those folks might develop a fever and/or rash after their MMR vaccine. So it is important to quickly figure out whether they are part of the outbreak and have a wild strain (maybe they were exposed before their vaccine could start to work) or are having a common, mild vaccine reaction.

But couldn’t they have vaccine-associated measles if they have a rash and fever and a vaccine strain? Theoretically, but then they would likely have true measles symptoms. And even in these rare case reports, the children didn’t spread the measles to anyone else.

So why are you waiting to know the genotype of the measles strain causing the outbreak in your area? Hopefully, it isn’t to help you decide whether or not to vaccinate and protect your kids. While it is interesting to know where the outbreak originated, you can bet that it isn’t a vaccine strain.

More on Vaccine Strains Causing Measles Outbreaks

How Often Should You Do Vaccine Titer Testing?

We sometimes hear about folks doing vaccine titer testing.

A vaccine titer is a blood test that can determine whether or not you are immune to a disease after you get a vaccine.

While that sounds good, after all, why not check and be sure, it has downsides. Chief among them is that the results aren’t always accurate.

That’s right. You can sometimes have a negative titer test, but still be immune because of memory B cells and the anamnestic response.

How Often Should You Do Vaccine Titer Testing?

So how often should you do vaccine titer testing?

It depends, but most folks might never have it done!

Why not?

Vaccines work very well, so you would typically not need to routinely check and confirm that you are immune after being vaccinated. And, this is also important, the vaccine titer tests don’t always work that well, titer testing isn’t available for all vaccines (you can’t do titer testing for Hib and pertussis), and the testing can be expensive.

So we usually just do the testing (a quantitative titer) for folks that are in high risk situations, including:

  • pregnancy – rubella titer only (HBsAg is also done, but that’s not a vaccine titer test, but rather to see if you are chronically infected with hepatitis B)
  • healthcare workers – anti-HBs (antibody to the hepatitis B surface antigen to confirm immunity after being vaccinated)
  • students in nursing school and medical school, etc. – anti-HBs
  • children and adults exposed in an outbreakmeasles, chicken pox, mumps, etc., but only if we are unsure if they were previously vaccinated and protected
  • after a needlestick injury, etc. – to confirm immunity to hepatitis B
  • babies born to a mother with hepatitis B – to confirm that their hepatitis B vaccine worked

Vaccine titer testing might also be done for:

  • internationally adopted children – to confirm that they are immune if we unsure about all of the vaccines the child got in other countries
  • children and adults with lost vaccine records – to confirm that they are immune, since we are unsure about all of the vaccines they got
  • evaluation of children and adults with immune system problems – to help identify what immune system problems they might have – typically involves checking pneumococcal titers, giving Prevnar, and then checking pneumococcal titers again
  • people at continuous or frequent risk for rabies – rabies titer testing every 6 months to 2 years
  • patients with inflammatory bowel disease, before starting immunosuppressive therapy – hepatitis A and hepatitis B titers, as they might be at increased risk for hepatitis

While checking titers is easy, it is sometimes harder to know what to do with the results you get.

Of all of these different titers, only one tells you that you are immune due to vaccination.
Of all of these different titers, only one tells you that you are immune due to vaccination.

It is especially important to know that:

  • most people don’t need to have their titers checked routinely if they are not in one of the high-risk groups noted above
  • it isn’t practical to get titers tested as a method of potentially skipping one or more doses of your child’s vaccines, after all, if the titer is negative, then you are still going to have to get vaccinated
  • a healthcare provider with a negative measles titer after two doses of the MMR vaccine does not need another dose of vaccine
  • a healthcare provider who has anti-HBs <10 mIU/mL (negative titer) after three doses of the hepatitis B vaccine should get another dose of vaccine and repeat testing in 1 to 2 months – if still <10 mIU/mL, they should then get two more doses of hepatitis B vaccine (for a total of 6 doses) and repeat testing. If still negative, these documented nonresponders will need HBIG as post-exposure prophylaxis for any future hepatitis B exposures, but no further doses of hepatitis B vaccine.
  • vaccinated women of childbearing age who have received one or two doses of rubella-containing vaccine and have rubella serum IgG levels that is not clearly positive should be administered one additional dose of MMR vaccine, with a maximum of three doses, and should not be tested again
  • postvaccination titer testing is not recommended after the chicken pox vaccine
  • in addition to not being able to test titers for pertussis and Hib immunity, it is becoming difficult to test poliovirus type 2 titers, as the test uses a live virus that isn’t routinely available anymore (type 2 polio has been eradicated)

Still think you need vaccine titer testing?

More on Vaccine Titer Testing

What Is a Vaccine?

You know what a vaccine is, right?

The word vaccine comes from the vaccinia virus that was in the original smallpox vaccine.
The word vaccine comes from the vaccinia virus that was in the original smallpox vaccine.

The flu shot you get each year is a vaccine.

Vaccine: A product that stimulates a person’s immune system to produce immunity to a specific disease, protecting the person from that disease. Vaccines are usually administered through needle injections, but can also be administered by mouth or sprayed into the nose.

Immunization: The Basics

The smallpox shot that Edward Jenner developed was a vaccine.

Vaccine Definitions

While that is an easy enough definition to understand, that there are many different types of vaccines does make it a little more complicated.

There are:

  • Live-attenuated vaccines – made from a weakened or attenuated form of a virus or bacteria
  • Inactivated vaccines – made from a killed form of virus or bacteria
  • Subunit, recombinant, polysaccharide, and conjugate vaccines – made from only specific pieces of a virus or bacteria
  • Toxoid vaccines – made to target a toxin that a bacteria makes and not the bacteria itself

And of course all of these types of vaccines work to produce immunity to specific diseases – vaccination.

Immunization: A process by which a person becomes protected against a disease through vaccination. This term is often used interchangeably with vaccination or inoculation.

Immunization: The Basics

What other definitions are important to know when you talk about vaccines?

  • active immunity – immunity that you get from having a disease (natural immunity) or getting a vaccine and making antibodies
  • adjuvant – a substance that helps boost your body’s immune response to a vaccine so that you can use a minimum amount of antigen, reducing side effects
  • antibodies – protective proteins that you make against antigens
  • antigens – specific substances (can be part of a virus or bacteria) that trigger an immune response
  • attenuation – a virus or bacteria that is made less potent, so that it can produce an immune response without causing disease
  • elimination – getting rid of a disease in a specific area
  • endemic – the baseline level of disease in an area
  • eradication – getting rid of a disease everywhere (smallpox)
  • epidemic – an increase in the number of cases of a disease over a large geographic area
  • herd immunity – when enough people in a community are protected and have immunity, so that disease is unlikely to spread
  • immunity – protection against a disease
  • incubation period – how long it takes to develop symptoms after you are exposed to a disease
  • outbreak – an increase in the number of cases of a disease over a small geographic area
  • pandemic – an increase in the number of cases of a disease over several countries or continents
  • passive immunity – temporary immunity that you get after being given antibodies, either via a shot of immunoglobulin or a mother’s antibodies are transferred to her baby through her placenta
  • placebo – classically defined as “a comparator in a vaccine trial that does not include the antigen under study”
  • quarantine – isolating someone so that they don’t get others sick
  • titer – an antibody count that can often be used to predict immunity

Got all of that?

So what about variolation, the process that was used before Jenner developed his smallpox vaccine? Was that also a vaccine?

It did produce immunity to smallpox, which is the basic definition of a vaccine, but still, variolation is typically concerned an immunization technique and not a vaccine.

More on Vaccine Definitions