Tag: measles

Challenging the Concept of Herd Immunity

Before we talked about clusters of unvaccinated children, experts warned about pockets of susceptibles.
Before we talked about clusters of unvaccinated children, experts warned about pockets of susceptibles.
The idea of herd immunity has been around since at least 1923 and became used to describe “the indirect protection afforded to individuals by the presence and  proximity of others who are immune.”

That’s not much different from how the CDC defines herd immunity today:

A situation in which a sufficient proportion of a population is immune to an infectious disease (through vaccination and/or prior illness) to make its spread from person to person unlikely. Even individuals not vaccinated (such as newborns and those with chronic illnesses) are offered some protection because the disease has little opportunity to spread within the community.

Also called community immunity, it is often misunderstood by folks in the anti-vaccine movement.

Challenging the Concept of Herd Immunity

That the idea of herd immunity is being challenged is not new.

“Along with the growth of interest in herd immunity,  there has been a  proliferation of views of what it means or even of whether it exists at all.”

Paul E. M. Fine Herd Immunity: History, Theory, Practice

If you get educated about vaccines and understand how herd immunity works, it is easy to refute these challenges, especially the idea that herd immunity isn’t real just because we still have outbreaks of vaccine-preventable diseases among highly vaccinated communities.

Why do we still have outbreaks then?

It is mostly because we live in open communities that don’t mix randomly.

Keep in mind that the best model for herd immunity is a randomly mixing closed community – “one in which the probability of contact within any time interval is the same for every choice of two individuals in the population.”

Again, that doesn’t mean herd immunity doesn’t work.

It just means we can expect to see some outbreaks when someone in a well vaccinated community visits another community with lower vaccination levels and more disease, gets sick, and returns.

“However,  within the population of a community,  there may be pockets of  susceptibles, either because prior epidemics have failed to spread into the group or because they have not accepted immunization.”

John P. Fox Herd Immunity

You must also consider the size of the community when thinking about herd immunity, for example, a family, school, neighborhood, or city, versus the entire state. So you can have herd immunity levels of protection at the state or city level because of high average vaccination levels, but pockets of susceptibles who live in the same neighborhood or go to the same school can mean that you don’t have herd immunity in those places, leading to outbreaks.

“Hib vaccine coverage of less than 70% in the Gambia was sufficient to eliminate Hib disease, with similar findings seen in Navajo populations.”

RA Adegbola Elimination of Hib disease from The Gambia after…

Lastly, there is not one herd immunity level for all diseases. It is a separate threshold for each and every disease, depending on how easily it spreads, how many people are already immune, how long immunity lasts, if there is a vaccine, and the effectiveness of the vaccine, etc. That means that a community can have herd immunity for Hib and polio, but not the flu, and for rubella and measles, but not pertussis.

What happened in The Gambia is a great example of herd immunity. After introducing a three dose primary Hib immunization schedule (no booster dose), rates of Hib meningitis quickly went from 200 per 100,000 to none. A few years later, there were 6 cases of Hib meningitis in mostly vaccinated children (no booster dose) and in the majority of cases, “close contacts had a history of frequent or recent travel to Senegal, a neighboring country with strong kinship links with The Gambia and where vaccination against Hib was not introduced” until the following year.

With a Hib meningitis rate of 3 per 100,000, they are still far below pre-vaccine levels of disease, and their situation doesn’t mean that herd immunity isn’t real, as you will understand once you review these myths about herd immunity.

Myths About Herd Immunity

What are some common myths about herd immunity?

  • that natural immunity is better than getting vaccinated. Not True. Natural immunity often comes with a price. Remember, many vaccine-preventable diseases are life-threatening, even in this age of modern medicine.
  • you can just hide in the herd. Not True. “Freeloaders” can gamble and hope that their intentionally unvaccinated kids won’t get a vaccine-preventable disease, but it won’t always work. There is a risk to “free-riding, in which individuals profit from the protection provided by a well-vaccinated society without contributing to herd immunity themselves.”
  • most adults aren’t immune because they haven’t been vaccinated or don’t get boosters, but since we aren’t seeing that many outbreaks, herd immunity itself must be a myth. Not True. Adults were either born in the pre-vaccine era and likely have natural immunity or were born in the vaccine era and are vaccinated and immune. But again, herd immunity is disease specific, so when we talk about herd immunity for measles, it doesn’t matter if they have immunity against hepatitis A or Hib. And adults get few boosters or catch-up vaccines. Also, 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.
  • most vaccines wear off too soon to provide long lasting protection for herd immunity to be real. Not True. While waning immunity is a problem for a few diseases, like pertussis and mumps, and you need boosters for others, like tetanus, vaccine induced immunity is typically long lasting and often life-long.
  • herd immunity wasn’t developed by observing immunized people, it was all about natural immunity. Not True. The first experiments about herd immunity by Topley and Wilson in 1923 involved vaccinated mice. Ok, they weren’t immunized people, but it wasn’t just about natural immunity! And much earlier, in 1840, it was noted that “smallpox would be disturbed, and sometimes arrested, by vaccination, which protected a part of the population.” That’s herd immunity he was talking about.
  • herd immunity is not a scientifically validated concept. Not True. It has been well studied for almost 100 years.
  • if herd immunity was real, diseases would be eradicated once you reached herd immunity levels. Not True. Reaching herd immunity levels simply starts a downward trend in disease incidence. A little more work has to be done at the final stages of eradication, like was done for smallpox and is being done for polio.
  • natural immunity causes much of the decrease in mortality from a disease in the developed world, even before a vaccine is introduced. Not True. While it is certainly true that there was a big drop in mortality in the first half of the 20th century for most conditions because of improvements in sanitation, nutrition, and medical science, it was not a consequence of natural herd immunity. And we continue to see significant levels of mortality and morbidity for many diseases in the modern era, especially for those that can’t yet be prevented by a vaccine, like RSV, West Nile Virus, and malaria, etc.
  • vaccines aren’t 100% effective, so herd immunity can’t really work. Not True. Part of the equation to figure out the herd immunity threshold for a disease takes into account the effectiveness of a particular vaccine.
  • folks with medical exemptions for vaccines put the herd at risk just the same as those who intentionally skip vaccines. Not True. Children and adults with medical exemptions, including immune system problems, those getting treatments for cancer, and other true medical exemptions don’t have a choice about getting vaccinated.

So, like other anti-vaccine myths, none of the herd immunity myths you may have heard are true.

That makes it hard to understand why Dr. Russel Blaylock goes so far as to say “that vaccine-induced herd immunity is mostly myth can be proven quite simply.” Does he just not understand herd immunity? That is certainly a possibility, because “although herd immunity is crucial for the elimination of infectious diseases, its complexity and explicit relationship to health politics cause it to remain under-explained and under-used in vaccine advocacy. ”

He is also really big into pushing the idea that adults have no or little immunity, because when he was in medical school, he was “taught that all of the childhood vaccines lasted a lifetime,” but it has now been discovered that “most of these vaccines lost their effectiveness 2 to 10 years after being given.”

The thing is, Blaylock graduated medical school in 1971, when the only vaccines that were routinely used were smallpox (routine use ended in 1972), DPT, OPV, and MMR (it had just become available as a combined vaccine in 1971). Of these, it was long known that smallpox, diphtheria, and tetanus didn’t “last a lifetime,” and the live vaccines OPV and MMR, except for the mumps component, actually do.

Blaylock, like most anti-vaccine folks who push myths about herd immunity, is plain wrong. And like most anti-vaccine myths, using herd immunity denialism to convince parents that it is okay to skip or delay vaccines puts us all at risk for disease.

What To Know About Herd Immunity Myths

Herd immunity is not junk science or a false theory. Herd immunity is real, it works, and explains how people in a community are protected from a disease when vaccination rates are above a certain threshold.

More About Herd Immunity Myths

Measles Vaccines vs Measles Strains

Most people understand that for every virus or bacteria, their can be multiple strains of the same organism that cause disease.

For example, there is flu A and B, swine flu, bird flu, and even dog flu.

In the case of flu, those different strains are a problem, because having immunity to one, doesn’t mean that you will have immunity to others. In fact, usually you won’t, whether it is natural immunity from a previous infection or immunity from a vaccine.

Pains with Strains

Do we have the same issues with other diseases?

We certainly have situations in which vaccines don’t cover all disease strains, including:

  • Gardasil – now covers nine strains of HPV that cause 90% of cervical cancers
  • Hib – only covers Haemophilus influenzae type b, which causes invasive disease, like meningitis, pneumonia, and sepsis, but not other Haemophilus influenzae strains that can cause ear infections
  • Polio – originally protected against three serotypes of polio, but monovalent (one strain) and bivalent (two strains) oral poliovirus vaccines have also been available to respond to outbreaks and bOPV is the one used for routine immunization, except in industrialized, polio-free countries that use the IPV shot
  • Prevnar – now covers 13 strains of Streptococcus pneumonia
  • Rotavirus – protects against severe disease caused by rotavirus strains that aren’t even in the vaccine

Fortunately, even when a vaccine doesn’t cover all strains, it does cover those that most commonly cause disease.

Measles Genotypes

Knowing the genotype of a measles strain can help you understand where measles outbreaks are coming from.
Knowing the genotype of a measles strain can help you understand where measles outbreaks are coming from.

What about measles?

There are at least 24 different genotypes of measles that come from 8 different clades (A-H), with even more wild type virus strains (based on those genotype).

These genotypes include A (all vaccine strains are genotype A), B2, B3, C1, C2, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11, G2, G3, H1, and H2.

In general, genotypes are restricted to a specific part of the world, such as:

  • African Region – B2, B3
  • Eastern Mediterranean Region – B3, D4, D8
  • European Region – D4, D5, D6
  • Southeast Asian Region – D4, D5, D8, D9, G2, G3, H1
  • Western Pacific Region – D5, D9, G3, H1

In countries that have eliminated measles, like the United States, the genotypes that are found will depend on from where the measles strain was imported.

Additionally, five genotypes, B1, D1, E, F, and G1 are now inactive.

Measles Strains

Specific strains of measles viruses include the vaccine strains (Edmonston, Moraten, Zagreb, Schwarz, AIK‐C, CAM, Leningrad-16, and Shanghai-191, etc.) plus wild strains, like:

  • MVi/NewYork.USA/94 – a wild strain of B3 genotype
  • Johannesburg.SOA/88/1 – a wild strain of D2 genotype
  • Manchester.UNK/30.94  – a wild strain of D8 genotype
  • Hunan.CHN/93/7 – a wild strain of H1 genotype

Why so many vaccine strains?

It may come as a surprise to some people, but the whole world doesn’t use the same vaccines. For example, unlike the United States, Japan has used measles vaccines derived from AIK‐C, CAM, and Schwarz strains of the measles virus.

And just how many wild strains of measles are there? It’s hard to know, but consider that a study of 526 suspected measles cases from 15 outbreaks over 3 years in one state of India found at least 38 different strains.

Myths About Measles Strains

Do the measles vaccines cover all of the measles strains that cause outbreaks around the world?

Yes they do, despite the myths you may hear about mutated measles strains.

This came up a lot during the Disneyland measles outbreak, when folks first tried to place blame on a vaccine strain and then on the fact that the outbreak strain didn’t match the vaccine strain.

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

CDC Measles Outbreak — California, Dec 2014–Feb 2015

And it is coming again in the latest measles outbreak in Minnesota. Could that outbreak be caused by a vaccine strain? Anything is possible, but it’s not. A communication’s director for the Minnesota Department of Health has confirmed that “that the virus strain making people sick in this outbreak is the B3 wild-type virus.”

Of course, none of these outbreaks are started by a vaccine strain of measles shed from someone who was recently vaccinated. It also had nothing to do with the fact that the strains didn’t match – after all we aren’t talking about the flu.

These outbreaks are imported from other countries by folks who typically aren’t vaccinated or are incompletely vaccinated and mostly spread among other people who are unvaccinated.

So what’s the most important thing to understand when considering all of these vaccine strains and wild strains of measles? It is that “there is only 1 serotype for measles, and serum samples from vaccinees neutralize viruses from a wide range of genotypes…”

In other words, the measles vaccine works against all strains of measles in all genotypes of measles. That makes sense too, because the measles virus, unlike influenza, is monotypic.

There is only one main type of measles virus, despite the many small changes in the virus that can help us identify different strains and genotypes. And these changes don’t affect how antibodies protect us against the measles virus.

What To Know About Measles Strains

The best way to get protected against all measles strains is to get vaccinated with two doses of the MMR vaccine.

More About Measles Strains

Updated May 23, 2017

Measles Deaths in the 21st Century

An infant hospitalized during a measles outbreak in the Philippines in which 110 people died.
An infant hospitalized during a measles outbreak in the Philippines in which 110 people died. Photo by Jim Goodson, M.P.H.

Measles is a big killer.

According to the WHO, “In 2015, there were 134,200 measles deaths globally – about 367 deaths every day or 15 deaths every hour.”

But it wasn’t that long ago, in 1980, that measles was causing at least 2.6 million deaths a year. And just 17 years ago, in 2000, measles caused about 777,000 deaths worldwide.

Measles Deaths in the 21st Century

While some experts doubt if we will ever truly eradicate measles, like we have done for smallpox, a lot of progress is being made on reducing measles outbreaks and deaths thanks to routine and supplemental immunizations.

Tragically, measles still kills.

“For every 1,000 children who get measles, one or two will die from it.”

CDC – Complications of Measles

And it is not just in developing countries that don’t have access to vaccines or adequate levels of vitamin A or modern healthcare.

During the 2010 and 2011 outbreaks in Europe, after all, with about 30,000 cases of measles each year, there were at least 28 deaths.

So far this year, according to the ECDC, there are reports of :

  • the death of a 10-month-old unvaccinated child in Bulgaria (among just 116 cases)
  • the death of a 17-year-old girl who was not vaccinated in Portugal (among just 29 cases)
  • 28 deaths in Romania, almost all unvaccinated children (among 6,434 cases since January 2016)
  • the death of a vaccinated man who was being treated for leukemia in Switzerland (among just 69 cases)
  • the death of a 37-year-old partially vaccinated women (the mother of 3 kids) in Essen, Germany (among about 634 cases)

Unfortunately, measles cases continue to rise in most of these countries and many others…

Are you planning a trip to Europe any time soon? How about Indonesia or Australia, for which the CDC has also issued travel health notices. Even if you aren’t, as these outbreaks rise, it increases the chances that another traveler will bring measles home and expose someone in your community, starting an outbreak.

And while we deal with folks who simply don’t want to vaccinate and protect their kids, no one should lose sight of the fact that “In 2015, there were 134,200 measles deaths globally – about 367 deaths every day or 15 deaths every hour.”

What To Know About Measles Deaths

Kids are still dying of measles and the big take away should be that it doesn’t take thousands of cases for there to be a death and it can happen to a healthy child in a developed country with modern healthcare.

Get Educated. Get Vaccinated. Stop the Outbreaks

More Information About Measles Deaths

Updated June 6, 2017

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About Those Measles Outbreaks in China

The MMR vaccine is one of the most effective vaccines ever made. Two doses are at least 99% effective at preventing measles infections. Even one dose is about 95% effective against measles.

We have measles outbreaks in the United States not because the MMR vaccine is not effective, but rather because there are still so many unvaccinated people around. Often, these unvaccinated people travel out of the country, get sick with measles, and start the outbreaks.

About Those Measles Outbreaks in China

A study in PLOS did not find massive outbreaks of measles in China despite high vaccination rates.
A study in PLOS did not find massive outbreaks of measles in China despite high vaccination rates.

But if the MMR vaccine is so effective, then why, as many anti-vaccine folks claim, is China having measles outbreaks when 99% are vaccinated?

The simple answer is that this claim is false – China is not having these big measles outbreaks among highly vaccinated people.

The source of the claim is from a real article in PLoS One, “Difficulties in Eliminating Measles and Controlling Rubella and Mumps: A Cross-Sectional Study of a First Measles and Rubella Vaccination and a Second Measles, Mumps, and Rubella Vaccination,” which found that in 2011, in Zhejiang province, there were:

  • 9 patients with measles, including 3 infants who were too young to be vaccinated and 6 young adults who were unsure if they had ever been vaccinated
  • 1122 patients with mumps
  • 186 patients with rubella

So no big measles outbreaks, but why the large number of cases of mumps and rubella?

History of Measles Vaccination in China

It becomes easy to understand when you look at their immunization schedule.

In the United States, the first live measles vaccine was introduced in 1963, the MMR was introduced in 1971, and a booster dose of MMR was added to the childhood immunization schedule in 1990. That helped to stop the endemic spread of measles in 2000 and rubella in 2004.

In contrast, the measles vaccine timeline has moved much slower in China:

  • a measles vaccine was introduced in 1966
  • continued use of a one-dose, single-antigen measles vaccine through the 1970s and mid-1980s
  • the addition of a single-antigen measles vaccine booster dose in 1985 to children who were 7-years-old
  • in 2007, the switch to a measles-rubella vaccine for 8 months old, with a MMR booster at 18-24 months
  • the addition of a measles-rubella vaccine booster for secondary school students in 2008
  • a campaign to get children between the ages of 8 months and 4 years vaccinated with a measles-mumps vaccine in 2010

So many of the children and young adults who had mumps and rubella would not have had a chance to get a mumps or rubella vaccine. They were too old when they started giving those vaccines and there was no catch-up for older children and adults.

The study authors conclude that a timely two-dose MMR vaccination schedule is recommended, with the first dose at 8 months and the second dose at 18–24 months. An MR vaccination speed-up campaign may be necessary for elder adolescents and young adults, particularly young females.

What To Know About Those Measles Outbreaks in China

Even considering the varied vaccine schedule, the study also clearly states that even for the measles vaccine, there is less than 95% coverage in almost all age groups and that measles cases are at an historic low.

It should be clear that anti-vaccine websites are putting out false information when they say that China is having measles outbreaks when 99% of the population is vaccinated.

More About Those Measles Outbreaks in China

Get a Vaccine Checkup Before Traveling with Your Kids

Get vaccinated. Measles is just a plane ride away.
Get vaccinated: Bring home fun souvenirs, photos, and fantastic memories, not measles!

Got plans to travel this spring or summer?

Going out of the country?

Taking the kids?

While a trip abroad can be a great experience for kids, whether you are just site seeing or you are visiting family, don’t forget to take some simple precautions so that your family comes back safe and healthy.

Get a Vaccine Checkup Before You Travel

It is important to remember that just because your kids are up-to-date on their routine childhood immunizations, that doesn’t mean that they are ready to travel out of the country.

It might surprise some folks to know that there are many vaccines that kids in the United States don’t routinely get, like vaccines that protect against cholera, yellow fever, typhoid, and Japanese encephalitis, etc. These are considered to be travel vaccines and may be recommended or required depending on where you are going.

How do you know which vaccines your kids need?

The CDC Traveler’s Health website is the best place to figure it out. With a list of 245 destinations, in addition to offering advice on how to avoid vaccine-preventable diseases, you get recommendations on avoiding others too, like Zika and malaria.

Don’t wait until the last minute before checking on these vaccine recommendations though. These are not vaccines that most pediatricians have in their office, so call or visit your pediatrician a few months in advance to plan out how you will get them. As a last resort, if your pediatrician can’t order them, can’t help you get them from an area pharmacy, and they aren’t available at your local health department, you might look to see if there is a “travel clinic” nearby.

Don’t Forget the Early MMR Recommendations

It’s also important to remember to make sure your child’s routine vaccines are up-to-date too. Confusing things a little, that can mean getting their MMR vaccines early.

Many parents, and some pediatricians,  often forget that before traveling out of the United States:

  • Infants 6 months through 11 months of age should receive one dose of MMR vaccine. While this early dose should provide protection while traveling, it doesn’t provide full protection, doesn’t count as the 12 to 15 month routine dose, and will need to be repeated.
  • Children 12 months of age and older should receive two doses of MMR vaccine separated by at least 28 days. So even if your child is less than 4-years, he or she needs two doses of MMR before traveling out of the country. This second early dose won’t have to be repeated when they do turn 4.
  • Teenagers and adults who do not have evidence of immunity against measles should get two doses of MMR vaccine separated by at least 28 days. While some adults are considered fully vaccinated with one dose of MMR, that isn’t true if they are traveling out of the country. Travelers need two doses!

Continuing outbreaks of measles linked to unvaccinated and partially vaccinated travelers highlight the need to spread the word about these recommendations.

Traveling is fun. Be sure to bring back some great memories and a few souvenirs. Don’t bring home measles or other diseases that you can then spread to others in your community or on the plane ride home.

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Hedda Get Bedda Doll and Other Measles Stories

Hedda Get Bedda originally came with a hospital bed.
The Hedda Get Bedda doll originally came with a hospital bed.

In the early 1960s, the American Character Doll Company produced a series of Whimsie dolls, including:

  • Annie the Astronut
  • Fanny the Flapper
  • Hilda the Hillbilly
  • Lena the Cleaner (baseball)
  • Samson the Strongman
  • Simon the Degree
  • Wheeler the Dealer (casino dealer)
  • Zero the Hero

Hardly politically correct for our times, the stereotyped dolls do provide a look at the history of their time.

One other doll, Hedda Get Bedda, is especially helpful in that sense.

Made in 1961, this Whimsie doll could change her face, letting you know how she was feeling when you turned the knob on her head. She could go from having a sleeping face, to a sick face (perhaps having chicken pox or measles), to a happy face (once you made her better).

Does the fact that she also came with a hospital bed mean anything?

Just like some anti-vaccine folks like to think that the simple fact that they made a doll that had measles or chicken pox could possibly mean that they looked at them as mild diseases, you could just as easily say that including the hospital bed means ‘they’ understand they were life-threatening diseases that could put land you in the hospital.

We are talking about the pre-vaccine era after all, and in 1961, and when the Hedda Get Bedda doll came out, there were about 503,282 cases of measles in the United States and 432 measles deaths.

Like the Brady Bunch measles episode, the Hedda Get Bedda doll is sometimes used to push the myth that vaccine-preventable diseases aren’t that serious, helping folks justify their decisions to intentionally skip or delay vaccines and leaving their kids unprotected.

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

Walter Orenstein, MD

For example, if you believed that measles, chicken pox, or Hib were mild diseases, then you might feel better about not getting your child the MMR, chicken pox, or Hib vaccines.

Sure, many people get measles and do get better without any complications. On their way to getting better though, even they have high, hard to control fever for 5 to 7 days, with coughing and extreme irritability.

But while most get better, we shouldn’t forget that some people don’t survive measles without complications. Natural immunity sometimes comes with a price, from vision problems and permanent hearing loss to brain damage.

And tragically, some people don’t get to survive measles.

Get Educated. Get Vaccinated.

For More Information and Measles Stories

News on the Latest Measles Outbreaks

Breaking News – We already have reports of measles cases in at least 116 people from 12 states (California, Florida, Maryland, Massachusetts, Michigan, Minnesota, Nebraska, New Jersey, New York, Pennsylvania, Utah, and Washington) in 2017, including an ongoing outbreak in Minnesota that is now up to 78 cases. Also many reports of measles outbreaks in Europe. (see below)

We have come a long way since the development of the first measles vaccines in the early 1960s…

Pre-Vaccine Era Measles Outbreaks

Unvaccinated children exposed to measles are quarantined for at least 21 days.
Unvaccinated children exposed to measles are quarantined for at least 21 days.

In the pre-vaccine era, measles was a very common childhood disease.

As it is now, it was also a deadly disease.

In the 1950s, there were 5,487,332 cases (just under 550,000 a year) and 4,950 deaths (about 500 each year).

In 1962, there were 469,924 cases of measles in the United States and 432 deaths.

Post-Vaccine Era Measles Outbreaks

The first measles vaccines were licensed between 1963 and 1965, but it was the first national measles eradication campaign in 1966 that got people vaccinated and measles rates down.

In 1970, there were only 47,351 cases and 89 deaths.

Rates continued to drop until the large outbreaks between 1989 to 1991, when there were 55,622 cases and 123 deaths. The addition of a measles booster shot got measles outbreaks under control again. By 2000, when measles was declared eliminated in the United States, there were just 86 cases and one death.

Post-Elimination Era Measles Outbreaks

Measles cases usually begin increasing in April and May. How many cases will we see this year?
Measles cases usually begin increasing in April and May. How many cases will we see this year?

Declaring measles eliminated in the United States didn’t mean that we didn’t have any more measles, after all, it hasn’t been eradicated yet. It just that we are no longer seeing the endemic spread of measles. Since 2000, measles outbreaks have been imported from outside the country, or at least they are started by cases that are imported.

We have seen more than a few records in the post-elimination era, including:

  • the year with the historic low number of measles cases – 37 cases in 2004
  • the year with the largest number of cases since 1994 – 667 cases in 2014
  • the largest single outbreak since the endemic spread of measles was eliminated – 377 cases in Ohio in 2014

In 2015, we got a reminder of how deadly measles can be. Although there have been other measles deaths and SSPE deaths in the past ten years, unlike the 2015 death, they are usually buried in CDC reports and aren’t published in the newspaper.

2017 Measles Outbreaks

An infant hospitalized during a measles outbreak in the Philippines in which 110 people died.
An infant hospitalized during a measles outbreak in the Philippines in which 110 people died. Photo by Jim Goodson, M.P.H.

The first new case of 2017 was an unvaccinated adult in San Luis Obispo County, California who was exposed to international travelers over the holidays. The person exposed others to measles at the Twin Cities Community Hospital emergency department in Templeton while contagious in early January.

The second case of 2017 was related to an LA county outbreak that started at the end of 2016 – a resident of Ventura County.

And it goes on already, with other measles cases in 2017 including:

  • at least 116 cases (as of mid-June)
  • cases in 12 states, including California, Florida, Maryland, Massachusetts, Michigan, Minnesota, Nebraska, New Jersey, New York, Pennsylvania, Utah, and Washington
  • an infant in San Luis Obispo County that was too young to be vaccinated and who had contact with an unvaccinated adult with measles
  • one new case in the Los Angeles County outbreak, which is now up to 20 confirmed measles cases (including 18 in LA County), all unvaccinated
  • four new cases in Ventura County, California that are linked to another Ventura County measles case and the LA County outbreak, which is now up to 24 cases
  • a case in Jersey City, New Jersey following international travel who exposed people at multiple places, including a hospital, pharmacy, mall, and on a commuter train
  • an infant in Suffolk County, New York who had been overseas
  • an unvaccinated 7-month-old baby from Passaic County, New Jersey who had been traveling out of the country and may have exposed others at area hospitals (a good reminder that infants who are at least 6 months old should get an MMR vaccine before leaving the country)
  • two cases in Salt Lake County, Utah – which began in a resident who had “received all appropriate vaccinations” and developed measles after traveling outside the US and then spread to another person “who had contact with the first case.” According to the SLCoHD, “One of the two individuals with measles had received one MMR vaccine.”
  • two cases in King County, Washington – a man and his 6-month-old infant, both unvaccinated, developed measles after traveling to Asia, and exposed many others around Seattle, including at a Whole Foods, a sandwich shop, their apartment building, and two Amazon buildings.
  • a confirmed case in Omaha, Nebraska, who exposed people on a Delta flight and multiple places in Douglas and Sarpy counties, including the Bergan Mercy Hospital Emergency Room.
  • a young child in Macomb Count, Michigan who required hospitalized and has been linked to international travel
  • a suspected case at William Allen White Elementary School in Lyon County, Kansas which has led to the quarantine of unvaccinated students for 3 weeks
  • an unvaccinated student at Laguna Beach High in Orange County, California, which led to the quarantine of at least 6 unvaccinated students
  • a staff member at Discovery Academy of Lake Alfred in Florida
  • an unconfirmed case in an infant who attended the College of Staten Island Children’s Center in New York
  • two children in Minnesota without a known source of infection
  • another child in Minnesota – among the three Somali Minnesotans in this outbreak are two children who are just two years old – all of the cases were unvaccinated and two required hospitalization, although the common source is still not known. Vaccine hesitancy has been a problem among the Somali Minnesotans because of Wakefield‘s MMR study.
  • five more unvaccinated children in Minnesota, as the outbreak grows to 8.
  • a confirmed case in North Platte, Nebraska who may have exposed others at a middle school, church youth group, the Great Plains Health Emergency Room, a medical office, and a lab.
  • a resident of Livingston County, Michigan who exposed others at area restaurants and St. Joseph Mercy Brighton Hospital after getting measles on a plane ride with an unvaccinated child
  • another case in Minnesota, bringing the outbreak count to 9 unvaccinated children.
  • three more cases in Minnesota, bringing this outbreak case count to 12, with at least 200 people in quarantine.
  • four possible cases in Nebraska
  • eight more cases in Minnesota, bringing this outbreak case count to 20 young children under age 5 years, and now including an infant under age 12 months.
  • four more cases in Minnesota, bringing this outbreak case count to 24 young children under age 5 years and surpassing the size of the 2011 measles outbreak in the Somali community in the same area, which was also mostly among intentionally unvaccinated children.
  • five more cases in Minnesota, including the first outside of Hennepin County – spreading to nearby Stearns County, bringing this outbreak case count to 29 young children under age 5 years, with only one that was vaccinated.
  • three more cases in Minnesota, as the outbreak spreads to the third county – Ramsey County.
  • more measles (2 new cases) in Minnesota (Hennepin County, Ramsey County, Crow Wing County, and now Le Sueur County), where the ongoing outbreak is up to 66 cases, almost all unvaccinated children and where there has been a call to accelerate the two dose MMR schedule for kids over age 12 months.
  • a teen visiting the United States from India who developed measles and exposed others at a hotel and a hospital in Bergen County, New Jersey and in upstate New York.
  • a child in Maryland who was admitted to Children’s National Medical Center in Washington, D.C.
  • more measles (3 new cases) in Minnesota (Hennepin County, Ramsey County, Crow Wing County, and Le Sueur County), where the ongoing outbreak that has been confirmed to be from the wild type B3 strain is up to 68 cases, almost all unvaccinated children.
  • a case in Pennsylvania who exposed others at a visitor center
  • someone who visited the MIT Museum in Cambridge, Massachusetts.
  • two new cases in Minnesota, ending speculation that the outbreak, now up to 70 cases, was over…
  • one new case in Minnesota, raising the number of cases in this ongoing outbreak to 78 cases.
  • the latest case – a healthcare worker in New York who is employed by Hudson Headwaters Health Network and also works at a Warren County medical practice.

How many cases will we end up with this year? It is certainly getting off to a quick start, which could mean a big year for measles, although it is certainly hard to predict what will happen.

2016 Measles Outbreaks

Starting slow, 2016 ended as a fairly average year for measles:

  • 83 cases
  • cases in 17 states, including Alabama, Arizona, California, Colorado, Connecticut, Florida, Georgia, Hawaii, Illinois, Massachusetts, Michigan, Minnesota, New York, North Carolina, Oregon, Tennessee, Texas, and Utah
  • a large outbreak in Arizona, 23 cases, linked to a private detention center
  • a large outbreak in Shelby County, Tennessee, at least seven cases, including six unvaccinated and one partially vaccinated child
  • an ongoing measles outbreak in Los Angeles County and Santa Barbara County that has been linked to the Los Angeles Orthodox Jewish community
  • a case in Colorado in which an unvaccinated adult traveled internationally and ended up exposing many people “from Dec. 21 to 29, 2016, who was at a wide variety of locations in the Denver-Boulder area,” including an Urgent Care center and the Parker Adventist Hospital Emergency Department

As in other years, many of these outbreaks involved unvaccinated children and adults. One case involved a child at the Yuba River Charter School in California, a Waldorf School with very high rates of unvaccinated children.

International Measles Outbreaks

The endemic spread of measles was stopped or eliminated in 2000. Since then, most of the measles outbreaks in the United States begin when someone travels out of the country, gets sick, and exposes others. Or less commonly, when an international traveler brings measles into the country.

That makes it easy to understand that large outbreaks of measles in other parts of the world could increase the risk that we have more outbreaks here. And that’s what happened in 2014 when there was an epidemic of measles in the Philippines and we ended up with the most cases since 1994, many linked to travel to and from the Philippines.

This year, the world is seeing large outbreaks of measles in:

  • European Union – Austria (78 cases), Belgium (293 cases, including 2 cases of encephalitis), Bulgaria (130 cases, including one death – a 10-month old unvaccinated child), Czech Republic (126 cases, including 2 cases of encephalitis), Denmark, France (189 cases, including 2 cases of encephalitis), Germany (698 cases, and a death in a 37-year-old mother of 3 children), Hungary (54 cases), Iceland (2 cases. 10-month-old unvaccinated twin siblings – the first cases in Iceland in 25 years!), Italy (2,988 cases), Portugal (31 cases, including one death), Slovakia, Spain (46 cases), and Sweden (19 cases). The largest outbreak is in Romania, where there have been 6,743 cases and 30 deaths in the past 13 months.
  • UK – 17 cases in 2017
  • Switzerland – the Swiss Sentinel Surveillance Network already reports 67 measles cases in 2017, compared to 36 in 2015 and 65 in 2016. Many of the cases are in young adults, aged 20-24 years. There has been one death, a vaccinated man being treated for leukemia.
  • Australia – 54 cases so far in 2017
  • New Zealand – 11 cases so far in 2017
  • Canada – at least 42 cases including an active outbreak in Nova Scotia.
  • Japan – 164 cases so far in 2017 (they had 8 in early June 2016…)
  • Congo – over 14,000 cases
  • Guinea – a measles epidemic has been declared in the country, with at least 1,527 cases and 2 deaths this year
  • Indonesia – island of Bali
  • South Africa – 60 cases, including an outbreak in Gauteng (24 cases) that is linked to one unvaccinated family.
  • Republican of South Sudan
  • Somalia – over 8,000 cases
  • Yemen
  • Uganda
  • Laos
  • Nigeria

These outbreaks are a great reminder to review the special vaccine travel requirements, including that adults who “plan to travel internationally should receive 2 doses of MMR at least 28 days apart,” that infants traveling abroad can get their first dose of MMR as early as age 6 to 11 months, with a repeat dose at age 12 months, and that “children aged who are greater than or equal to 12 months need 2 doses of MMR vaccine before traveling overseas,” even if they aren’t four to six years old yet.

Get Educated. Get Vaccinated. Stop the Outbreaks.

For More Information On Measles Outbreaks:

Updated on June 17, 2017

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