Tag: herd immunity

Measles Returns to California

Is anyone surprised that a student in California has measles?

A health advisory about measles in Santa Clara County.

Actually, a lot of folks are probably surprised. After all, didn’t lawmakers in California recently pass a law that mandated everyone in school get vaccinated?

Well yeah, but SB277 didn’t apply to all students. Only new students and those transitioning to a new grade span (for example, moving from K-6th to 7th grade) have to meet the new minimum immunization requirements. That means it will take more than a few years until all of the kids already in school whose parents have skipped or delayed any vaccines have gotten caught up or have graduated.

And that means we will still see some of these outbreaks of vaccine preventable diseases.

There is also a little issue with medical exemptions somehow rising being abused after the personal belief exemption was eliminated in the state…

Measles Outbreaks in California

When you think of measles and California, most people probably think of the 2015 Disneyland outbreak, which was linked to:

  • 134 cases in California, including at least 50 cases without a known source
  • 13 cases in Arizona, Nebraska, Utah, Colorado, Washington, and Oregon
  • 1 case in Mexico
  • 159 cases in Canada

The Disneyland outbreak included a lot of intentionally unvaccinated kids and kept unvaccinated kids from school, closed daycare centers, and led to hospitalizations of more than a few people.

“The ongoing measles outbreak linked to the Disneyland Resort in Anaheim, California, shines a glaring spotlight on our nation’s growing antivaccination movement and the prevalence of vaccination-hesitant parents.”

Majumder et al. on Substandard Vaccination Compliance and the 2015 Measles Outbreak

Schools in California were closed for at least two weeks in 1917 because of measles epidemics.

The Disneyland outbreak wasn’t the first big measles outbreak in California in recent years though.

No, I’m not talking about the really big outbreaks from the pre-vaccine era. Or even the outbreaks in the late 1980s, just before we started giving an MMR booster. Believe it or not, 75 people died between 1988 and 1990 with measles – just in California.

More recently, there was the 2008 outbreak in San Diego that was triggered by an unvaccinated 7-year-old boy who had traveled to Switzerland with his family.

He returned with measles and got at least 10 other unvaccinated children sick, including four infants who were too young to be vaccinated and were unknowingly exposed at their pediatrician’s office.

“Almost 100 children (including babies who were too young for the MMR vaccine) were quarantined or hospitalized after they were exposed at the pediatrician’s office, Whole Foods or day care. In all, 11 children caught the measles. As it turns out, the boy who spread measles is a patient of Dr. Bob Sears…”

OC’s Dr. Bob Sears discusses measles outbreak on NPR

One of those infants was hospitalized when his fever spiked to 106 degrees and he wouldn’t eat or drink.

“We spent 3 days in the hospital fearing we might lose our baby boy. He couldn’t drink or eat, so he was on an IV, and for a while he seemed to be wasting away. When he began to be able to drink again we got to take him home. But the doctors told us to expect the disease to continue to run its course, including high fever—which did spike as high as 106 degrees. We spent a week waking at all hours to stay on schedule with fever reducing medications and soothing him with damp wash cloths. Also, as instructed, we watched closely for signs of lethargy or non-responsiveness. If we’d seen that, we’d have gone back to the hospital immediately.”

Megan Campbell on 106 Degrees: A True Story

Measles cases also began rising in 2011, as unvaccinated travelers brought measles back from trips to Europe, Asia, and Africa, where there were large outbreaks.  There were 31 measles cases in California in 2011.

While 31 cases might not seem like much, consider that between 2001 through 2006, there were just 66 cases in California, with only 4 cases in 2005!

Will we ever get to a year with just 4 cases in California again?

It didn’t happen in 2017.

Last year started with a big outbreak in Los Angeles County that grew to include at least 24 cases and a few surrounding counties. There was also a case involving an unvaccinated student at Laguna Beach High in Orange County which led to the quarantine of at least 6 unvaccinated students.

The Latest California Measles Outbreak

What kind of a measles year will we see in 2018 in California?

There is just one case, so far.

Did you eat lunch at the Westgate Center food court on Friday, March 2?
Did you eat lunch at the Westgate Center food court on Friday, March 2?

An unvaccinated student returned from a trip to Europe and developed measles, exposing others between February 28 through March 2 in Santa Clara County at a school in Campbell and at the Westgate Center food court in San Jose.

An infant hospitalized during a measles outbreak in the Philippines in which 110 people died.
The measles rash begins 3-5 days after other measles symptoms, which is why measles is often hard to diagnose.

With an average incubation period of 10 to 12 days, that means exposed people might begin to show symptoms by March 14. Keep in mind that the incubation period can be as long as 21 days though, so be on the watch for measles symptoms until at least March 23 if you could have been exposed.

Would you recognize measles?

It is important to understand that the first symptoms of measles don’t include a rash. Instead, you get a high fever, runny nose, cough, and pink eye. The measles rash comes a few days later, as the high fever continues.

It is also important to understand the the MMR vaccine is safe and works very well to prevent measles.

This exposure is a great reminder that vaccines are necessary and that you shouldn’t wait for your kids to get exposed to get them caught up and vaccinated and protected.

What to Know About Measles Outbreaks in California

A recent outbreak of measles in California, this time in Santa Clara County, is a good reminder that the MMR vaccine is necessary to keep your kids protected.

More on Measles Outbreaks in California

What Is Vaccine Choice?

Have you heard about the idea of vaccine choice?

The “right to choose” is being pushed by anti-vaccine groups in many states because they think that laws mandating kids to have vaccines to go to daycare, school, and college violates their parental rights and civil liberties.

“Their claim that vaccines are 100% safe and effective for all people all of the time is not based in science and is not supported by facts or evidence, making it more of a religious belief than an adequate basis for their mandate argument.”

Texans for Vaccine Choice

And of course, they use a lot of anti-vaccine talking points to try and scare parents into believing them. Vaccines are safe and they work, but no one says that they are 100% safe or that they are 100% effective.

What Is Vaccine Choice?

Right away, you should see another big problem with the vaccine choice movement.

No one is forcing anyone to get vaccinated. Everyone has a choice. It’s just that some folks don’t like the consequences that come with that choice of not vaccinating their kids – having to home school their kids instead of going to a public or private school.

So basically, vaccine choice is just the anti-vaccine movement moving the goal posts yet again.

“If you ask a parent of an autistic child if they want the measles or the autism, we will stand in line for the f–king measles.”

Jenny McCarthy

Study after study showed that vaccines are not associated with autism and what did we get, measles outbreaks in unvaccinated kids.

What’s Missing In the Vaccine Choice Argument?

In addition to facts, one big thing that is missing from the vaccine choice argument is that by pushing the idea that unvaccinated kids should be allowed to skip or delay any or all vaccines without consequences, that takes away the choice for the rest of us who want to keep our kids protected from vaccine-preventable diseases.

Can’t we just vaccinate our kids?

Many children with cancer and other medical conditions benefit from herd immunity.
Many children with cancer and other medical conditions benefit from herd immunity. (CC BY 2.0)

We do!

But that doesn’t take away all of the risk if you don’t vaccinate your kids.

“…the increased risk of disease in the pediatric population, in part because of increasing rates of vaccine refusal and in some circumstances more rapid loss of immunity, increases potential exposure of immunodeficient children.”

Medical Advisory Committee of the Immune Deficiency Foundation

There are kids who are too young to be vaccinated or fully vaccinated, kids who can’t be vaccinated because of true medical vaccine exemptions, and folks whose vaccine didn’t work, after all, vaccines aren’t 100% effective.

The “choice” folks don’t talk about those things though.

Make an informed choice about vaccines before you think about leaving your child unvaccinated and unprotected.

What To Know About Vaccine Choice

Listen to anti-vaccine propaganda, skip or delay vaccines and leave your kids unprotected or do your research and understand that vaccines work and are safe and necessary and get them vaccinated and protected – that’s your vaccine choice.

More on Vaccine Choice

What Shots Do You Need to Be Around a Newborn?

We often focus on what vaccines a baby will need once they are born, but it is also important that folks around your new baby get vaccinated too.

What Shots Do You Need to Be Around a Newborn?

To protect their new baby, many parents institute a no visit policy for friends and family members who don't get vaccinated.
To protect their new baby, many parents institute a no visit policy for friends and family members who don’t get vaccinated.

Of course, all of your vaccines should be up-to-date, especially if you plan to be around young kids. That’s how we maintain herd immunity levels of protection for those who can’t be vaccinated and protected, including newborns who are too young to be vaccinated.

In addition to routine vaccines, it is especially important that teens and adults who are going to be around a newborn or younger infant have:

  • a dose of Tdap – now routinely given to kids when they are 11 to 12 years old and to women during each pregnancy (to protect newborns against pertussis), others should get a dose if they have never had one. There are currently no recommendations for a booster dose.
  • a flu shot – is it flu season? Then anyone who is going to be around your baby should have had a flu shot. And for the purposes of keeping a newborn safe from the flu, you can assume that flu season extends from September through May, or anytime that flu shots are still available.

That’s it?

Only two shots?

Yes, only two shots assuming you are either immune or are up-to-date on your other vaccines. If you have been delaying or skipping any vaccines, then you might need an MMR, the chicken pox vaccine, and whatever else you are missing.

Other Precautions Around a New Baby

Unfortunately, there are many risks to a new baby that aren’t vaccine preventable.

Just because everyone is vaccinated and protected, that doesn’t mean that you should have a party welcoming your baby home and invite everyone in the neighborhood. Besides the flu, we get concerned about other cold and flu-like viruses, especially RSV.

That means to protect them, you should keep your baby away from:

  • large crowds, or even small crowds for that matter – in general, the more people that your baby is exposed to, the higher the chance that they will catch something
  • people who are sick
  • cigarette smoke – second hand smoke increases the risk of infections, like RSV

And make sure everyone, even if they don’t seem sick, washes their hands well before handling your baby.

“Parents or relatives with cold sores should be especially careful not to kiss babies—their immune systems are not well developed until after about 6 months old.”

AAP on Cold Sores in Children: About the Herpes Simplex Virus

Because you can sometimes be contagious even if you don’t have an active cold sore (fever blister), some parents don’t let anyone kiss their baby. Most of this fear comes after news reports of babies getting severe or life-threatening herpes infections after a probable kiss from a family member or friend.

When Can I Take My Newborn Out in Public?

When can you take your baby out in public? Most people try to wait until they are at least two months old.

Is that because that’s when they are protected with their two month shots?

Not really, as your baby won’t really be protected until they complete the primary series of infant vaccinations at six months.

Two months is a good general rule though, because by that age, if your baby gets a cold virus and a fever, it won’t necessarily mean a big work-up and a lot of testing. Before about six weeks, babies routinely get a lot of testing to figure out why they have a fever (the septic workup), even if it might be caused by a virus. That’s because younger infants are at risk for sepsis, UTI’s, and meningitis and they often have few signs when they are sick.

Keep in mind that going out in public is much different from going out. You can go for a walk with your baby at almost any time, as long as they are protected from the sun, bugs, and wind, etc., as long as there aren’t people around.

What to Know About Protecting Newborn Babies

Protect your baby by making sure everyone around them is vaccinated and protected, especially with a dose of Tdap and the flu vaccine.

More on Protecting Newborn Babies

Answers To Frequently Asked Questions About Immunizations

Have questions about your child’s immunizations?

We probably have the answers.

Answers To Frequently Asked Questions About Immunizations

Not surprisingly, many parents have the same questions about immunizations and they want answers to reassure themselves that they are doing the right thing for their kids by getting them vaccinated and protected.

Still have questions?

Rotavirus vaccines are associated with a very small risk of intussusception, but that is not a good reason to miss the benefits of this vaccine.
Like most pediatricians, my kids are vaccinated and protected. Photo by Vincent Iannelli, MD

With so much misinformation out there scaring folks about vaccines, that’s not surprising.

Just keep in mind that every anti-vaccine talking point and myth they push has an easy answer, even as folks continue to move the goalposts in search of new arguments against vaccines.

Yesterday it was mercury. Today it’s aluminum. Tomorrow it will be something else, while they continue to use vaccine scare videos to make you think that vaccines aren’t safe.

Parents who do their research understand that the real threat to their kids isn’t vaccines, it is the anti-vaccine experts that continue to push propaganda about vaccines.

What to Know About Answers To Frequently Asked Questions About Immunizations

The most basic answers to your questions about vaccines are that while vaccines aren’t perfect, they are safe and necessary and they do work well to protect us from vaccine-preventable disease.

More on Frequently Asked Questions About Immunizations

Do More Vaccinated or Unvaccinated Kids Get Sick in Outbreaks?

Some anti-vaccine folks continue to claim that vaccines don’t work and that most outbreaks of vaccine-preventable diseases are actually caused by kids who have been vaccinated.

They also push the myth that more vaccinated than unvaccinated kids get sick in most outbreaks.

Vaccinated vs Unvaccinated in an Outbreak

So are outbreaks usually caused by kids who have been vaccinated?

No, of course not.

Do we sometimes see more vaccinated than unvaccinated kids in some of these outbreaks?

Yes, sometimes we do.

Vaccine Epidemiology

Wait, what?

Yes, we sometimes see more vaccinated than unvaccinated kids in an outbreak.

How can that be if vaccines work?

It is actually very easy to understand once you learn a little math and a little more epidemiology.

Basically, it is because while vaccines work, they don’t work 100% of the time, and more importantly, there are way more vaccinated kids around than unvaccinated kids.

The Mathematics of Disease Outbreaks

That means that you need to understand that more than the absolute number of vaccinated and unvaccinated people that got sick in an outbreak, you really want to know the percentages of vaccinated vs unvaccinated kids who got sick.

For example, in a school with 1,000 kids, you might be very surprised if six kids got a vaccine preventable disease, and three of them were vaccinated, leaving three unvaccinated.

Does that really mean that equal amounts of vaccinated and unvaccinated kids got sick?

I guess technically, but in the practical sense, it only would if half of the kids in the school were unvaccinated. Now unless they go to a Waldorf school, it is much more likely that over 90 to 95% of the kids were vaccinated, in which case, a much higher percentage of unvaccinated kids got sick.

Before we use a real world example, some terms to understand include:

  • attack rate – how many people will get sick when exposed to a disease
  • basic reproductive number or Ro – different for each disease, Ro basically tells you  just how contagious a disease is and ranges from about 1.5 for flu, 8 for chicken pox, and 15 for measles
  • vaccine coverage – how many people are vaccinated
  • vaccine efficacy – how well a vaccine works

You also need to know some formulas:

  • attack rate = new cases/total in group
  • vaccine coverage rate = number of people who are fully vaccinated / number of people who are eligible to be vaccinated
  • vaccine effectiveness = (attack rate in unvaccinated group – attack rate in vaccinated group) / attack rate in unvaccinated group x 100

Unfortunately, it is often hard to use these formulas in most outbreaks.


For one thing, it is hard to get accurate information on the vaccination status of all of the people in the outbreak. In addition to those who are confirmed to be vaccinated or unvaccinated, there is often a large number who’s vaccination status is unknown. And even if you know the vaccination status of everyone in the outbreak, it can be even harder to get the vaccine coverage rate or a neighborhood or city.

Outbreaks of Vaccine Preventable Diseases

Reports of measles outbreaks among highly vaccinated populations are from before we started doing a second dose in 1994.
Reports of measles outbreaks among highly vaccinated populations are from before we started doing a second dose of MMR… way back in 1994.

We know what starts most outbreaks.

And no, it’s not shedding

For example, with measles, it is typically an unvaccinated person who travels out of the country, returns home after they have been exposed but are still in their incubation period, and then exposes others once they get sick. And the great majority of folks in these measles outbreaks are unvaccinated.

Some examples of these outbreaks include:

  • the 2014 Ohio measles outbreak that started with two unvaccinated Amish men getting measles in the Philippines while on a missionary trip and ended up with at least 388 cases before it was over, almost all unvaccinated
  • a 2013 North Carolina measles outbreak with 22 cases started after an unvaccinated traveler had returned from India
  • an outbreak of measles in New York, in 2013, with at least 58 cases, tarted with an intentionally unvaccinated teen returning from a trip to London
  • a 2011 outbreak of measles in Minnesota, when an unvaccinated child traveled out of the country, developed measles, and returned to his undervaccinated community, causing the state’s largest measles outbreak in 20 years

But what about mumps and pertussis?

Those outbreaks are all among vaccinated kids, right?


In one of the biggest mumps outbreak, in Arkansas, only 71% of people were up-to-date on their vaccines!

And keep in mind that while we do know that there are issues with waning immunity with some vaccines, you are still much more likely to become infected and get others sick if you are not vaccinated. And you will likely have a much more severe disease.

A 2013 pertussis outbreak in Florida is a good example that even with all the bad press it gets, the DTaP and Tdap vaccines work too. This outbreak was started by an unvaccinated child at a charter school with high rates of unvaccinated kids. About 30% of unvaccinated kids got sick, while there was only one case “in a person who reported having received any vaccination against pertussis.”

In another 2013 pertussis outbreak in Florida, this time in a preschool, although most of the kids were vaccinated, the outbreak started with “a 1-year-old vaccine-exempt preschool student.” And the classroom with the highest attack rate, was “one in which a teacher with a laboratory-confirmed case of pertussis who had not received a Tdap booster vaccination, worked throughout her illness.”

In outbreak after outbreak, we see the same thing, sometimes with deadly consequences – an unvaccinated child or adult triggers an outbreak and then a lot of unvaccinated folks get sick. Unfortunately, others get caught up in these outbreaks too, including those too young to be vaccinated, those who can’t be vaccinated because of true medical exemptions, and those whose vaccines may not have worked as well as we would have liked.

Get educated.

Vaccines are safe. Vaccines are necessary. Vaccines work.

What to Know About Vaccinated vs Unvaccinated in Outbreaks

Most outbreaks are started by someone who is unvaccinated, often after a trip out of the country, and the resulting outbreak will likely get many more unvaccinated than vaccinated folks sick.

More About Vaccinated vs Unvaccinated in Outbreaks

What Are the Benefits of the Flu Shot?

So that flu shot you got isn’t going to be 100% effective this year…

That doesn’t mean that you didn’t make a great decision getting your family vaccinated and protected! Or that you shouldn’t still take the time to go out and get a flu shot if you haven’t yet.

The flu vaccine works, even if it isn’t perfect.

Benefits of the Flu Shot

The benefits of the flu shot go far beyond just avoiding the flu.
The benefits of the flu shot go far beyond simply helping you avoid the flu. Most flu related deaths in children are in those who are unvaccinated.

What good is the flu shot if it doesn’t completely eliminate your risk of catching the flu?

How about the simple fact that even if doesn’t completely eliminate that risk 100%, a flu shot does decrease your risk of getting sick with the flu?

But it doesn’t end there.

Other benefits of a yearly flu shot include that it can:

  • reduce the risk of flu-associated death in children with underlying high-risk medical conditions by just over half (51%)
  • reduce the risk of flu-associated death in healthy children by just over two thirds (65%) – this is important, because despite what most people believe, many of the kids who die with the flu each year don’t have any underlying health problems
  • reduce how sick you get, even if you do get the flu, reducing “deaths, intensive care unit (ICU) admissions, ICU length of stay, and overall duration of hospitalization among hospitalized flu patients.”
  • reduce the risk of the babies getting hospitalized in their first 6 months when pregnant moms got a flu shot
  • reduce asthma attacks leading to emergency visits and/or hospitalizations in people with asthma

Getting vaccinated can also reduce the risk that you get sick with the flu and get someone else sick.

Considering all of these benefits, it is hard to imagine why anyone wouldn’t get a flu shot, even in year’s when it might just be 60% or even 40% effective.

I mean, it isn’t like the flu shot is actually going to give you the flu or anything…

Have you gotten your flu shot yet this flu season?

What to Know About the Benefits of the Flu Shot

In addition to helping you avoid getting sick with the flu, getting a yearly flu shot has many other indirect benefits, so that even if you get the flu, it can help you avoid getting really sick and ending up in the hospital, ICU, or getting so sick that you don’t survive.

More on the Benefits of the Flu Shot

Updated February 17, 2018

Alternatives to Getting Vaccinated

Are there any alternatives to getting vaccinated?

Sure. You can read about them all day long from holistic “experts” and on anti-vaccine websites.

Are there any good alternatives to getting vaccinated?

No. At least not if you want to be truly protected from vaccine-preventable diseases.

Alternatives to Getting Vaccinated

Kids who are born with immune disorders don't have to live in isolation bubbles any more, but they still need protection.
Kids who are born with immune disorders don’t have to live in isolation bubbles any more, but they still need protection. Photo by Baylor College of Medicine

Unfortunately, some folks don’t have other options and they need to look at an alternative for protection from vaccine-preventable diseases that doesn’t include vaccines.

These are the folks with contraindications or true medical exemptions for vaccines.

What do they do?

It depends on the specific circumstances, but in most cases, except for live vaccines or any other specific vaccine that is contraindicated, they usually get vaccinated.

Extremely few people can’t get at least some, if not most, of their vaccines, even if they do have contraindications to some others. And many exemptions are temporary.

“Parents need to balance the need of the immunoreconstituted child (post-transplant SCID) to be protected from exposure to infection from live vaccines and close contact–transmitted vaccine-derived infection with the need of the child to integrate into society and develop social and learning skills in group environments.”

Medical Advisory Committee of the Immune Deficiency Foundation

They also try to avoid people who are sick and  try to make sure that everyone around them is vaccinated to help maintain herd immunity levels of protection.

Neither is always possible though.

Post-Exposure Prophylaxis

Post-exposure prophylaxis is another option that is available to help prevent some vaccine-preventable diseases. For example, if your unvaccinated child is exposed to measles, they can often receive immune globulin to help them avoid getting measles.

Regimens for post-exposure prophylaxis are also available for:

  • chicken pox – varicella zoster immune globulin or immune globulin
  • diphtheria – antibiotics
  • hepatitis A – immune globulin
  • hepatitis B – hepatitis B immune globulin
  • influenza – oseltamivir (Tamiflu) and zanamivir
  • meningococcal disease – antibiotics
  • pertussis – antibiotics
  • rabies – rabies immune globulin
  • tetanus – tetanus immune globulin

When possible, immunization typically accompanies these post-exposure prophylaxis regimens.

There is one big problem with these types of post-exposure prophylaxis regimens though. You are not always going to know when your child is exposed to someone else with a vaccine-preventable disease. While some exposures might be obvious, like if your child steps on a rusty nail or is bitten by an unvaccinated dog who has rabies, you might miss some others.

Bogus Alternatives to Getting Vaccinated

What other alternatives to getting vaccinated are out there?

Unfortunately, there are none that work.

Many bogus alternatives to getting vaccinated are pushed by those opposed to vaccines as ways to boost your immunity, and they can include:

  • breastfeeding – while breastfeeding is great and always encouraged, the passive immunity it provides will not protect your baby from most vaccine-preventable diseases, as it contains IgA antibodies, not the IgG antibodies you would need to prevent diseases like measles, tetanus, chicken pox, and Hib, etc.
  • homeopathic vaccines – nosodes are homeopathic vaccines that have been diluted so much that they are supposed to retain a memory of the original substance. Even if they did – that’s not how immunology works.
  • herbs – neither echinacea, goldenseal root, nor elderberry syrup is going to boost your child’s immunity
  • vitamins – unless your child is severely vitamin deficient, taking vitamins isn’t going to boost their immunity, whether they are taking extra vitamin C or extra vitamin D
  • foods – Japanese mushrooms, kale, broccoli, lettuce, cabbage, avocados, ginger, black currants, graviola, green veggies, onion seeds, and berries might all be great to eat, but they aren’t going to boost your immunity
  • probiotics – they may help prevent antibiotic associated diarrhea, but there is not much evidence that taking them regularly does anything else
  • essential oils – they sometimes smell nice, but they aren’t going to boost your child’s immune system
  • chiropractic adjustments – not going to work
  • sun exposure – in addition to the worries about skin cancer, not only does extra sun exposure not boost your immune system, the WHO reports that “Several studies have demonstrated that exposure to environmental levels of UV radiation alters the activity and distribution of some of the cells responsible for triggering immune responses in humans. Consequently, sun exposure may enhance the risk of infection with viral, bacterial, parasitic or fungal infections, which has been demonstrated in a variety of animal models.”
  • fermented cod liver oil – this is not going to boost your child’s immune system, but folks should also know that there have been reports that the products that people have been buying and using for years were rancid and actually making them sick! There are much better ways to get vitamin D and vitamin A in your diet than taking fermented cod liver oil each day.

What about natural immunity?

While natural immunity can in some ways be more effective than vaccine induced immunity, it often comes at a price. You have to recover from the disease, hopefully without any long term consequences, to develop natural immunity.

What to Know About Alternatives to Getting Vaccinated

People who truly can’t be vaccinated rely on herd immunity, because in most cases, there are no effective alternatives for vaccines.

More On Alternatives to Getting Vaccinated