Tag: vaccine effectiveness

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

Making a Better Pertussis Vaccine

So we know that we need a better pertussis vaccine.

DTaP and Tdap just aren’t doing the job that they should be doing.

Whooping Cough is back, again.
Whooping Cough is back, again.

So when will we get one?

Making a Better Pertussis Vaccine

Since anti-vaccine folks are always talking about the 300 new vaccines in the pipeline, you would think that we would have had several new pertussis vaccines by now…

Unfortunately, we don’t.

What we do have is some good candidates, including:

  • new acellular pertussis vaccines, either with more antigens or an adjuvant
  • a new live attenuated nasal vaccine, BPZE1
  • new whole-cell vaccines with reduced endotoxin contents (so should have fewer side effects that then original whole-cell pertussis vaccine – DTP)

Before you get too excited, keep in mind that none of these vaccines will be available in your pediatrician’s office any time soon. Developing a new vaccine takes a lot of time.

BPZE1 has started phase 2a trials though.

What do we do until we get new pertussis vaccines?

“We should be more vigilant than we have been in the past to recognize and treat pertussis in all age groups so that transmission to young infants is reduced. Most important (although not discussed in this review) is to ensure that all pregnant women receive the Tdap vaccine between 27 and 36 weeks’ gestation with each pregnancy. Also, we should consider routinely administering Tdap vaccine every 3 years to all adolescents and adults who were primed with a DTaP vaccine.”

James D. Cherry on The 112-Year Odyssey of Pertussis and Pertussis Vaccines—Mistakes Made and Implications for the Future

We should keep using the pertussis vaccines we have!

Vaccines work, even when they aren’t as effective as we would like.

More on Making a Better Pertussis Vaccine

We Know Vaccines Work

We know vaccines work.

How well do they work?

In addition to eradicating smallpox, did you know that vaccines have helped eliminate four other now vaccine-preventable diseases?

  1. diphtheria
  2. neonatal tetanus
  3. polio
  4. congenital rubella syndrome

And unlike measles, which was declared eliminated in 2000, we really don’t see these diseases anymore.

We Know Vaccines Work

How well do vaccines work?

Let’s look at the disease counts (morbidity data), how many kids got sick, just before we developed a vaccine and where we are now:

DiseasePre-Vax EraNow% Decrease
Smallpox110,672last case 1977 100%
Diphtheria30,508199.9%
Pertussis265,26913,43994.9%
Tetanus6012096.7%
Neonatal Tetanus1,000+0100%
Polio21,269last case 1993100%
Measles763,094372 99.9%
Mumps212,9342,25198.9%
Rubella488,796599.9%
Congenital Rubella Syndrome20,0000100%
Hib invasive18,0002799.9%
HepB300,0002,79999.1%
Perinatal HepB16,20095294.1%
Pneumococcal invasive64,40098698.5%
HepA254,51811,16695.6%
Varicella5,358,5956,89299.9%

Sandra Roush and Trudy Murphy provided us with pre-vaccine baselines for 13 vaccine-preventable diseases in their article, Historical Comparisons of Morbidity and Mortality for Vaccine-Preventable Diseases in the United States.

“A greater than 92% decline in cases and a 99% or greater decline in deaths due to diseases prevented by vaccines recommended before 1980 were shown for diphtheria, mumps, pertussis, and tetanus. Endemic transmission of poliovirus and measles and rubella viruses has been eliminated in the United States; smallpox has been eradicated worldwide. Declines were 80% or greater for cases and deaths of most vaccine-preventable diseases targeted since 1980 including hepatitis A, acute hepatitis B, Hib, and varicella. Declines in cases and deaths of invasive S pneumoniae were 34% and 25%, respectively.”

Roush et al on Historical Comparisons of Morbidity and Mortality for Vaccine-Preventable Diseases in the United States.

Their study, which came out in 2007, used morbidity (2006) and mortality (2004) data that was recent at the time. The data has held up very well since then, looking at 2018 statistics in the National Notifiable Infectious Diseases Weekly Tables (see below), even with talk of waning immunity for some vaccines.

But can’t you explain all of this decline away by talking about better hygiene, sanitation, and nutrition?

Of course not!

“…for those trained in pediatrics in the 1970s, Hib (Haemophilus influenzae type b) was a horror.”

Walter Orenstein, MD

The pre-vaccine era for Hib was just before 1988, when the first Hib vaccine came out. We had good hygiene, sanitation, and nutrition in the 1980s and yet, a lot of kids died from Hib meningitis and epiglottitis. At least they did until he got a vaccine to prevent it.

And if it was better hygiene and sanitation, etc., why did it affect every disease at a different time? And why hasn’t better hygiene and sanitation stopped RSV, HIV, norovirus, Zika, and all of the other non-vaccine-preventable diseases?

Although there was a decline in mortality rates at the beginning of the 20th Century for all diseases thanks to better hygiene, sanitation, and nutrition, that effect plateaued by the mid-1930s. And since a lot of people were still getting sick, remember everyone used to get measles, even if a small percentage would die, it would add up to a lot of deaths!

Vaccines aren’t perfect, but they are safe, with few risks, and work well. Get vaccinated and protected if you want to keep from getting and bringing back these now vaccine-preventable diseases.

More on We Know Vaccines Work

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