Tag: Hib

Vaccines for Kids with Asplenia

Asplenia means lack of a spleen or a spleen that doesn’t work.

Although the spleen is an important organ that helps your body fight infections, in addition to other functions, it is certainly possible to live without a spleen.

Asplenia

There are many reasons a child might have asplenia, including:

  • congenital asplenia (children born without a spleen), sometimes associated with severe cyanotic congenital heart disease, such as transposition of the great arteries
  • surgical removal (splenectomy) secondary to trauma or anatomic defects
  • surgical removal to prevent complications of other conditions, such as ITP, hereditary spherocytosis, pyruvate kinase deficiency, Gaucher disease, and hypersplenism, etc.

And some children simply have a spleen that doesn’t work (functional asplenia) or doesn’t work very well because of sickle-cell disease and some other conditions.

Vaccines for Children with Asplenia

Because the spleen has such an important function in helping fight infections, without a spleen, a child is at increased risk for infections.

Specifically, there is a risk for severe infections from the Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis bacteria.

Fortunately, there are vaccines that protect against many subtypes of these bacteria, including:

  • Hib – protects against Haemophilus influenzae type B
  • Meningococcal conjugate vaccines – Menactra or Menveo, which protect against 4 common types of the Neisseria meningitidis bacteria – serogroups ACWY
  • Serogroup B Meningococcal vaccines – Bexsero or Trunemba, which protect against Neisseria meningitidis serogroup B
  • Prevnar 13 – protects against 13 subtypes of Streptococcus pneumoniae
  • Pneumovax 23 – protects against 23 subtypes of Streptococcus pneumoniae

Although Prevnar, Hib, and the meningococcal vaccines (Menactra or Menveo and Bexsero or Trunemba) are part of the routine immunization schedule, there are additional recommendations that can change the timing for when kids get them if they have asplenia.

Some kids need extra protection from vaccines.
Some kids need extra protection from vaccines. Photo by Janko Ferlic.

According to the latest recommendations, in addition to all of the  other routine immunizations that they should get according to schedule, children with asplenia should get:

  • one dose of the Hib vaccine if they are older than age 5 years “who are asplenic or who are scheduled for an elective splenectomy” and have not already vaccinated against Hib. Unvaccinated younger kids should get caught up as soon as possible. In general though, Hib is given according to the standard immunization schedule. This recommendation is about kids who are behind on the shot.
  • two doses of a meningococcal conjugate vaccine, either Menactra or Menveo, two months apart once a child with asplenia is at least two years old and a booster dose every five years. Infants with asplenia can instead get a primary series of Menveo at 2, 4, 6, and 12 months, with a first booster dose after three years, and a second booster after another five years. Older infants can get Menactra at 9 and 12 months, again, with a first booster dose after three years, and a second booster after another five years. While these vaccines are recommended for all kids, those with asplenia get them much earlier than the standard age.
  • either a two dose series of Bexsero or a three dose series of Trunemba, once they are at least 10 years old. The Men B vaccines are only formally recommended for high risk kids, others can get it if they want to be protected.
  • between one to four doses of Prevnar, depending on how old they are when they start and complete the series. Keep in mind that unlike healthy children who do not routinely get Prevnar after they are 5 years old, older children with asplenia can get a single dose of Prevnar up to age 65 years if they have never had it before. Like Hib, this recommendation is about kids who are behind on the shot.
  • a dose of Pneumovax 23 once they are at least two years old, with a repeat dose five years later and a maximum of two total doses. Kids who are not high risk typically don’t get this vaccine.

Ideally, children would get these vaccines at least two to three weeks before they were going to get a planned splenectomy. Of course, that isn’t always possible in the case of the emergency removal of a child’s spleen, in which case they should get the vaccines as soon as they can.

More About Asplenia

In addition to these vaccines, preventative antibiotics are typically given once a child’s spleen is removed or is no longer working well. Although there are no definitive guidelines for all children who have had a splenectomy, many experts recommend daily antibiotics (usually penicillin or amoxicillin) until a child is at least 5 years old and for at least 1 year after their splenectomy.

Other less common bacteria that can be a risk for children with asplenia can include Escherichia coli, Staphylococcus aureus, Salmonella species, Klebsiella species, and Pseudomonas aeruginosa. Vaccines aren’t yet available for these bacteria, so you might take other precautions, such as avoiding pet reptiles, which can put kids at risk for Salmonella infections.

Children with asplenia are at increased risk for severe malaria and babesiosis (a tickborne illness) infections. That makes it important to take malaria preventative medications and avoid mosquitoes if traveling to places that have high rates of malaria and to do daily tick checks when camping, etc.

A medical alert type bracelet, indicating that your child has had his spleen removed, can be a good idea in case he ends up in the emergency room with a fever and doctors don’t know his medical history.

Keep in mind that since there are many different causes of asplenia, the specific treatment plan for your child may be a little different than that described here. Talk to your pediatrician and any pediatric specialists that your child sees.

What to Know about Vaccines for Children with Asplenia

Children with asplenia typically need extra vaccines and protection against pneumococcal disease, Hib, and meningococcal disease.

More about Vaccines for Children with Asplenia

Why Didn’t Everyone Die with Our 1980s Level of Vaccination Rates?

This is actually a real question that someone recently asked:

“Can someone please explain how we survived the 1980s with vaccination rates well below “herd immunity” thresholds and far fewer vaccines? Why didn’t everyone die?”

J.B. Handley

Mr. Handley even provides a nice chart to give his question some context.

Vaccination rates for 2 year old children in 1985.
The chart shows vaccination rates for 2 year old children in 1985.

So why didn’t everyone die?

That’s easy.

While vaccine-preventable diseases can be life-threatening, they certainly don’t kill everyone who gets them. They are not 100% fatal. Well, rabies usually is, but not surprisingly, rabies wasn’t on his little chart…

Deaths from Vaccine-Preventable Diseases, 1985

What else does Mr. Handley miss?

“Comparisons between rates obtained from immunization records versus the total sample (records and recall) conducted on data collected between 1979 and 1983 showed that the USIS, which accepted parental recall, underestimated the true vaccination rate in preschoolers by as much as 23% for some antigens.”

Simpson et al on Forty years and four surveys: How does our measuring measure up?

The vaccination rates he is citing were based on a phone survey that wasn’t thought to be very accurate, underestimating true vaccination rates. It was last used in 1985.

While vaccination rates weren’t great at the time, they just weren’t as horrible as he makes it seem, but we still had some deaths from vaccine-preventable diseases. Not as bad as the pre-vaccine era though, when hundreds of people died with measles each year.

Here’s the data from the CDC for 1985:

https://www.cdc.gov/vaccines/pubs/pinkbook/downloads/appendices/E/reported-cases.pdf

  • 23 deaths from tetanus
  • 4 deaths from pertussis
  • 4 deaths from measles
  • 1 death from rubella
  • 2 cases of congenital rubella syndrome

Unfortunately, it got worse. This was just before the large measles outbreaks from 1989 to 1991, when 123 people died. During those three years, there were also 28 deaths from pertussis, 6 deaths from mumps, 13 deaths from rubella and 77 cases of congenital rubella syndrome!

But then we learned our lesson and we got kids vaccinated. But most of the problems then were about access to vaccines, not parents who intentionally skipped or delayed vaccines for their kids.

Deaths from non-Vaccine-Preventable Diseases, 1985

The CDC Morbidity and Motality Weekly Report includes summaries of notifiable diseases in the United States.Many of the diseases on J.B. Handley’s chart weren’t yet vaccine-preventable in 1985. They were quite deadly though, which is why vaccines were being developed and were eventually added to the schedule to protect our kids from getting them.

But in 1985 (*or in the years before the vaccine was introduced), tragically, the CDC lists:

  • 80 deaths from hepatitis A
  • 490 deaths from hepatitis B
  • 68 deaths from chicken pox
  • 219 deaths from Hib meningitis in children and about another 45 deaths from Hib epiglotittis
  • at least 200 deaths from pneumococcal disease in children*
  • 257 deaths from meningococcal infections
  • 20 to 60 deaths each year from rotavirus infections*

Want us to Turn Back the Clock and go back to an immunization plan (the Jenny McCarthy schedule) that didn’t include vaccines against any of these diseases? We would end up back to when kids still died of meningitis, pneumonia, blood infections, severe dehydration, epiglottitis, and cancer from Hib, pneumococcal disease, rotavirus, hepatitis B, hepatitis A, chicken pox, HPV, and meningococcal disease.

And the answer to Mr. Handley’s question becomes even more obvious.

How did we survive the 1980s with vaccination rates well below “herd immunity” thresholds and far fewer vaccines?

Many people didn’t.

What to Know About Deaths and Vaccination Rates

Poor vaccination rates and fewer vaccines led to more deaths from now vaccine preventable diseases in the mid-1980s.

More on Deaths and Vaccination Rates

 

Grave Reminders of Life Before Vaccines

Need a reminder of just how serious vaccine preventable diseases can be?

Don’t remember the pre-vaccine era?

That could be why some folks are so quick to think that skipping or delaying vaccines is a safe option for their kids.

Vaccines are necessary.

Without them, we will see even more outbreaks of measles, mumps, and pertussis and kids will continue to die of rabies, tetanus, and other now vaccine-preventable diseases.

The South Park Cemetary was begun in 1891 during a diphtheria epidemic.
A diphtheria cemetery in Wyoming.

Isolation hospitals and pest houses were commonly used to quarantine folks with smallpox.
Isolation hospitals and pest houses were commonly used to quarantine folks with smallpox and other now vaccine-preventable diseases.

Even mild smallpox, as depicted on this WHO Smallpox Recognition Card, included flu like symptoms, a few weeks of pustules, and then waiting for the lesions to scab over...
Even mild smallpox, as depicted on this WHO Smallpox Recognition Card, included flu like symptoms, a few weeks of pustules, and then waiting for the lesions to scab over…

People continued to die of smallpox well into the 20th century, even though an effective vaccine was developed in 1796.
People continued to die of smallpox well into the 20th century, even though an effective vaccine was developed in 1796.

In the pre-vaccine era, we had outbreaks of polio, and other, now vaccine-preventable diseases.
Outbreaks of polio would once isolate entire towns, as parents feared their kids would get sick too.

Fight Polio Poster
When was the last time you saw a child with polio?

Before wide use of the Hib and Prevnar vaccines, infants with fever would routinely get spinal taps and you would hope for clear fluid (cloudy fluid could be a sign of a bacterial infection).
Before wide use of the Hib and Prevnar vaccines, younger infants with fever would routinely need spinal taps and you would hope for clear fluid (cloudy fluid could be a sign of a Hib or Strep pneumo infection).

In the pre-vaccine era, Hib caused epiglottitis, meningitis, and pneumonia - all life-threatening diseases that are now prevented by the Hib vaccine.
In the pre-vaccine era, Hib caused epiglottitis, meningitis, and pneumonia – all life-threatening diseases that are now prevented by the Hib vaccine.

Before the 1990s, when the Hib vaccine available, hospitals had an epiglottitis team on call and always available.
Before the 1990s, when the Hib vaccine available, hospitals had an epiglottitis team on call and always available.

News of the Newark kids going to Paris to get Pasteur's rabies vaccine made the front page of the New York Times.
In 1885, several boys from Newark went all of the way to Paris to get Pasteur’s new rabies vaccine, as the disease had always been fatal up until that time.

Even if they survive, kids can lose fingers, toes, or even arms and legs to meningococcemia.
Even if they survive, kids can lose fingers, toes, or even arms and legs to meningococcemia.

Roald Dahl's daughter died of measles in 1962, the year before the development of the first measles vaccine.
Roald Dahl’s daughter died of measles in 1962, the year before the development of the first measles vaccine.

Nationwide, at least 123 people died in the United States during a large measles epidemic from 1989 to 1991, during a time that we had good sanitation, nutrition, and medical care.
Nationwide, at least 123 people died in the United States during large measles epidemics from 1989 to 1991, a time when we had good sanitation, nutrition, and medical care, but some folks weren’t vaccinated and we weren’t yet giving a second dose of MMR.

A papilloma caused by HPV on the vocal cords of a child with recurrent respiratory papillomatosis.
A papilloma caused by HPV on the vocal cords of a child with recurrent respiratory papillomatosis. (CC BY 4.0)

You don't have to go back to the pre-vaccine era to know that pertussis kills.
You don’t have to go back to the pre-vaccine era to know that pertussis kills. Ten infants died in 2010 in California from pertussis infections.

We should never forget what life was like before vaccines.

We should know that vaccine-preventable diseases were rarely mild, natural immunity comes at a cost, and that those who died from smallpox, diphtheria, measles, and polio aren’t around to talk about their experiences on Facebook (survivorship bias).

We should never forget that vaccine-preventable diseases were once big killers, and the only reason some folks have grown to fear the side effects of vaccines more than the diseases they prevent, is because we don’t see those diseases very much any more. If more people skip or delay getting vaccinated, we will though.

immunization-program-stages
As more people are vaccinated and diseases disappear, they forget how bad those diseases are, skip or delay getting their vaccines, and trigger outbreaks. Photo by WHO

Vaccines are safe and vaccines work.

Get vaccinated and protected.

Outbreaks of vaccine-preventable diseases belong in the past.

What to Know About Life Before Vaccines

Forgetting the pre-vaccine era and the benefits of vaccines makes folks susceptible to anti-vaccine talking points and scares them away from vaccinating and protecting their kids.

More on Remembering Life Before Vaccines

What to Do If Your Child Is Exposed to Meningitis

Meningitis is classically defined as an inflammation of the membranes that cover the brain and spinal cord, and it can be caused by:

  • viruses – also called aseptic meningitis, it can be caused by enteroviruses, measles, mumps, and herpes, etc.
  • bacteria – Streptococcus pneumoniae, Neisseria meningitidis, Listeria monocytogenes, Haemophilus influenzae type b (Hib), Group B strep
  • a fungus – Cryptococcus, Histoplasma
  • parasites – uncommon
  • amebas – Naegleria fowleri

Surprisingly, there are even non-infectious causes of meningitis. These might be include side-effects of a medication or that the child’s meningitis is a part of another systemic illness.

What to Do If Your Child Is Exposed to Meningitis

While meningitis can be contagious, it greatly depends on the type of meningitis to which they are exposed as to whether or not your child is at any risk.

Teens and young adults need two different kinds of meningococcal vaccines to get full protection.
Teens and young adults need two different kinds of meningococcal vaccines to get full protection.

So while the general advice is to “tell your doctor if you think you have been exposed to someone with meningitis,” you should try and gather as much information as you can about the exposure.

This information will hopefully include the type of meningitis they were exposed to, specifically if it was bacterial or viral, the exact organism if it has been identified, and how close of an exposure it was – were they simply in the same school or actually sitting next to each other in the same room.

For example, while the CDC states that “people who are close contacts of a person with meningococcal or Haemophilus influenzae type b (Hib) meningitis are at increased risk of getting infected and may need preventive antibiotics,” they also state that “close contacts of a person with meningitis caused by other bacteria, such as Streptococcus pneumoniae, do not need antibiotics.”

And you often don’t need to take any preventive measures if you are exposed to someone with viral meningitis.

While that might sound scary, it is basically because you typically aren’t at big risk after this kind of exposure. You could get the same virus, but the chances that it would spread and also cause meningitis are very unlikely.

Not only does Viera Scheibner think that vaccines cause SIDS and shaken baby syndrome, she thinks they are contaminated with amoeba.
The Naegleria fowleri ameba that can cause meningitis can be found in warm freshwater, including lakes and rivers.

Other types of meningitis, like primary amebic meningoencephalitis (PAM) and fungal and parasitic meningitis aren’t even contagious.

The Histoplasma fungus spreads from bird or bat droppings, for example, not from one person to another.

And parasites typically spread from ingesting raw or undercooked food, or in the case of Baylisascaris procyonis, from ingesting something contaminated with infectious parasite eggs in raccoon feces.

What to Do If Your Unvaccinated Child Is Exposed to Meningitis

Vaccines can prevent a number of different types of meningitis.

From Hib and Prevnar to MMR and the meningococcal vaccines, our children routinely get several vaccines to prevent meningitis.

While these meningitis vaccines don’t protect us from all of the different types of viruses, bacteria, and other organisms that can cause meningitis, they do prevent many of the most common.

So what do you do if your unvaccinated child is exposed to meningitis?

You should immediately call your pediatrician or local healthy department, because they might need:

  • antibiotics (usually rifampin, ciprofloxacin, or ceftriaxone) if the meningitis was caused by Neisseria meningitidis
  • antibiotics (rifampin) if the meningitis was caused by Haemophilus influenzae type b (Hib)

The availability of these antibiotics isn’t a good reason to skip or delay getting vaccinated though, as you won’t always know when your kids have been exposed to meningitis and not all types of vaccine-preventable meningitis can be prevented with antibiotics.

Of course, getting fully vaccinated on time is the best way to prevent many of these types of meningitis and other life-threatening diseases.

What to Do If Your Vaccinated Child Is Exposed to Meningitis

Even if your child is vaccinated, they might still need preventative antibiotics if they are exposed to someone with Hib or meningococcal meningitis, as vaccines are not 100% effective.

“Regardless of immunization status, close contacts of all people with invasive meningococcal disease , whether endemic or in an outbreak situation, are at high risk of infection and should receive chemoprophylaxis.”

AAP Red Book on Meningococcal Infections

This is especially true if they are not fully vaccinated.

Remember, to be fully vaccinated against Haemophilus influenzae type b, kids get a 2 or 3 dose primary series of the Hib vaccine when they are infants and a booster dose once they are 12 months old.

In the case of exposure to Hib meningitis, antibiotic prophylaxis would be recommended if:

  • the child is fully vaccinated, but there is a young child, under age 4 years, in the house who is unvaccinated or only partially vaccinated
  • the child is fully vaccinated, but there is another child in the house who is immunocompromised
  • the child is only partially vaccinated and under age 4 years
  • there is an outbreak in a preschool or daycare, with 2 or more cases within 60 days

And anyone exposed to someone with meningococcal meningitis should likely get antibiotics (chemoprophylaxis), even if they are fully vaccinated.

Talk to your pediatrician or local health department if your child is exposed to meningitis and you aren’t sure what to do, whether or not your child has been vaccinated.

What to Know About Getting Exposed to Meningitis

Learn what to do if your child is exposed to someone with meningitis, especially if they are unvaccinated, or have been exposed to someone with Hib meningitis or meningococcal disease.

More on Getting Exposed to Meningitis

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