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.
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.
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.
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.
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.
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.
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
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.
Believe it or not, there are some anti-vaccine folks who believe that all vaccines are dangerous and unnecessary. And they believe that pediatricians push vaccines on kids in all situations, using a one-size-fits-all kind of immunization schedule.
There are some true medical contraindications and precautions to getting vaccinated though. Still, it is important to remember that even more things are simply “conditions incorrectly perceived as contraindications to vaccination.”
Contraindications To Vaccinating Your Kids
There are actually some good reasons to delay or skip one or a few of your child’s vaccines, but only in some very specific situations.
These very specific situations are called contraindications and are what count as medical exemptions.
“A vaccine should not be administered when a contraindication is present; for example, MMR vaccine should not be administered to severely immunocompromised persons.”
CDC on Vaccine Contraindications and Precautions
Fortunately, there are not that many of these contraindications, they are usually specific to just one or a few vaccines, and they are usually, but not always, temporary.
That’s why it would be really unusual to get a true permanent medical exemption for all vaccines. Even if you had a severe allergy to a vaccine that contained yeast, latex, or gelatin, since vaccines contain different ingredients, you would very likely be able to safely get the others.
Remember, your doctor can’t, or at least shouldn’t, just make up contraindications and exemptions to help you avoid getting your kids vaccinated and help you keep them in school.
“I do not believe vaccines had anything to do with my child’s autism. I never noticed any change in his speech, behavior or development with vaccines. I believe the protection and benefits of vaccines far outweigh the risks!”
Michele Han, MD, FAAP
Autism, for example, has been shown to not be associated with vaccines, so it is not a contraindication to getting vaccinated. That’s why many parents vaccinate and protect their autistic kids!
Precautions To Vaccinating Your Kids
In addition to contraindications to getting vaccinated, there is an accompanying list of precautions.
“A precaution is a condition in a recipient that might increase the risk for a serious adverse reaction, might cause diagnostic confusion, or might compromise the ability of the vaccine to produce immunity (e.g., administering measles vaccine to a person with passive immunity to measles from a blood transfusion administered up to 7 months prior). A person might experience a more severe reaction to the vaccine than would have otherwise been expected; however, the risk for this happening is less than the risk expected with a contraindication. In general, vaccinations should be deferred when a precaution is present. However, a vaccination might be indicated in the presence of a precaution if the benefit of protection from the vaccine outweighs the risk for an adverse reaction.”
CDC on Vaccine Contraindications and Precautions
Again, we are fortunate that most of the conditions that are listed as precautions are temporary.
The vaccine information sheet that you get with each vaccine will list contraindications and precautions on who should not get the vaccine.
In fact, the most common is having a “moderate or severe acute illness with or without fever.”
Don’t want to get your child vaccinated when he or she has a severe illness?
Don’t worry.
Your pediatrician usually doesn’t want to vaccinate your child in that situation either.
It is easy enough to wait a few days or a week to get vaccinated, when the illness has passed, keeping in mind that a “mild acute illness with or without fever” is neither a precaution nor a contraindication to getting vaccinated. So you can still get your child their recommended vaccines if they just have a cold, stomach bug, or ear infection, etc.
What to Know About Precautions and Contraindications to Vaccines
Although there are some true medical exemptions or contraindications and precautions to getting vaccinated, most are vaccine specific and many are temporary, so they shouldn’t keep you from getting your child at least mostly vaccinated and protected.
More on Precautions and Contraindications to Vaccines
“Vaccines protect the health of children and adults and save lives. They prevent life – threatening diseases, including forms of cancer. Vaccines have been part of the fabric of our society for decades and are one of the most significant medical innovations of our time.”
More than 350 medical, professional and advocacy organizations in a 2017 letter to President Trump
It is the hundreds of thousands of experts at every major health organization around the world!
American Academy of Pediatrics
The American Academy of Pediatrics, an organization of 66,000 primary care pediatricians, pediatric medical subspecialists and pediatric surgical specialists, has long advocated for the health and safety of our children.
“Vaccines are safe. Vaccines are effective. Vaccines save lives.
Claims that vaccines are linked to autism, or are unsafe when administered according to the recommended schedule, have been disproven by a robust body of medical literature. Delaying vaccines only leaves a child at risk of disease. Vaccines keep communities healthy, and protect some of the most vulnerable in our society, including the elderly, and children who are too young to be vaccinated or have compromised immune systems.”
Fernando Stein, MD, FAAP, President and Karen Remley, MD, MBA, MPH, FAAP, CEO/Executive Vice President, American Academy of Pediatrics
Vaccine friendly pediatricians who are pushing non-standard, parent-selected, delayed protection vaccine schedules are leaving kids at risk for vaccine-preventable diseases.
“Pediatricians who routinely recommend limiting the numbers of vaccines administered at a single visit such that vaccines are administered late are providing care that deviates from the standard evidence-based schedule recommended by these bodies.”
AAP on Countering Vaccine Hesitancy
Vaccines are necessary.
“Because rare medically recognized contraindications for specific individuals to receive specific vaccines exist, legitimate medical exemptions to immunization requirements are important to observe. However, nonmedical exemptions to immunization requirements are problematic because of medical, public health, and ethical reasons and create unnecessary risk to both individual people and communities.”
AAP on Medical Versus Nonmedical Immunization Exemptions for Child Care and School Attendance
Society of Pediatric Nurses
“Immunizations are safe and effective in promoting health and preventing disease.”
SPN Position Statement on Immunizations
National Association of Pediatric Nurse Practitioners
Established in 1973, with more than 8,500 members, the National Association of Pediatric Nurse Practitioners (NAPNAP) is the professional association for pediatric nurse practitioners (PNPs) and all pediatric-focused advanced practice registered nurses (APRNs).
“NAPNAP supports the prioritization of immunization education for parents, guardians and other caregivers of infants, children, and adolescents. This education must include the most current scientific evidence related to vaccine safety, risk, benefits and current resources available to ensure that parents and caregivers receive adequate information about immunizations. This includes, when necessary, relaying the risk of not immunizing their child and potential devastation that can occur when a child is infected with a vaccine-preventable disease. It is incumbent that a PNP also be aware of misinformation in the public domain and provides the correct information to the public as well as the health care community.”
NAPNAP Position Statement on Immunizations
American College of Preventive Medicine
“Vaccine-preventable diseases were a major cause of mortality and morbidity in the United States in the 20th century. With the advent of immunizations, there have been dramatic rates of decline in these diseases. Clinical studies have shown vaccines to be efficacious and cost effective. ”
ACPM on Childhood Immunizations
American College of Obstetricians and Gynecologists
Founded in 1951, the American College of Obstetricians and Gynecologists (The College) represents more than 58,000 members.
“Health care providers and patients should be aware that the reassuring safety data for use of the aforementioned vaccines in pregnancy are compelling, and there is no link to vaccine administration and miscarriage. An added benefit to immunizing during pregnancy is the potential for disease prevention in newborns by way of passive antibody transfer to the fetus. Hence, offering pregnant patients influenza and Tdap vaccines is an avenue to protect newborn infants at a critically vulnerable time and before neonates can be vaccinated.”
ACOG on Immunization for Pregnant Women
American Public Health Association
The American Public Health Association was founded in 1872, the APHA represents over 25,000 public health professionals.
“And further noting that the Institute of Medicine has recently released a report10 describing the U.S. immunization system as “a national treasure that is too often taken for granted” and calling for substantial increases in federal and state allocation of funds to support immunization infrastructure; therefore
Reaffirms its support for immunization as one of the most cost-effective means of preventing infectious diseases;”
APHA on The Need for Continued and Strengthened Support for Immunization Programs
American Medical Association
The American Medical Association, which was founded in 1847, has just over 240,000 members.
“The AMA fully supports the overwhelming body of evidence and rigorous scientific process used by the Advisory Committee on Immunization Practices which demonstrate vaccines are among the most effective and safest interventions to both prevent individual illness and protect the health of the public.”
William E. Kobler, MD, member of the AMA Board of Trustees.
Immune Deficiency Foundation
“The development of immunizations for common bacterial and viral infections has represented a major advance in the battle against microbial organisms that constantly threaten the welfare of humankind and particularly the pediatric population. However, the alarming increase in nonimmunized persons could lead to a return of the epidemics seen in the past.
…critical need for maintenance of herd immunity in the population at large. It is particularly important for family members of patients with defective T and B lymphocyte–mediated immunity to receive all of the available standard immunizations (excluding live poliovirus).”
Medical Advisory Committee of the Immune Deficiency Foundation on Recommendations for live viral and bacterial vaccines in immunodeficient patients and their close contacts
American Nurses Association
The American Nurses Association (ANA), founded in 1896, represents “the interests of the nation’s 3.6 million registered nurses.”
“To protect the health of the public, all individuals should be immunized against vaccine-preventable diseases according to the best and most current evidence outlined by the Centers for Disease Control and Prevention (CDC) and the Advisory Committee on Immunization Practices (ACIP). All health care personnel (HCP), including registered nurses (RNs), should be vaccinated according to current recommendations for immunization of HCP by the CDC and Association for Professionals in Infection Control and Epidemiology (APIC).
…
As stated in the Code of Ethics for Nurses (ANA, 2015, p. 19), RNs have an ethical responsibility to “model the same health maintenance and health promotion measures that they teach and research…,” which includes immunization against vaccine-preventable diseases.”
ANA Position Statement on Immunizations
Autism Science Foundation
“Multiple studies have been completed which investigated the measles, mumps and rubella vaccination in relation to autism. Researchers have also studied thimerosal, a mercury-based preservative, to see if it had any relation to autism. The results of studies are very clear; the data show no relationship between vaccines and autism.”
The American Association of Immunologists (AAI) is the largest professional association of immunologists in the world, representing more than 7,600 basic and clinical immunologists.
“Recent outbreaks have brought increased attention to vaccine- preventable diseases and have highlighted the need for robust and timely immunization to reduce preventable sicknesses and deaths. AAI strongly urges full adherence to recommended vaccination schedules and views vaccines as efficacious for individuals and crucial to public health.
…
Research has repeatedly confirmed that vaccinations are safe and highly effective for all healthy children and adults, and any suggestions to the contrary have been discredited. Ongoing vaccine research continually reaffirms its safety and efficacy, including the number of vaccines administered at any one time and the recommended vaccination schedule.”
The American Association of Immunologists Statement on Vaccines
American Osteopathic Association
“The American Osteopathic Association supports the Centers for Disease Control and Prevention in its efforts to achieve a high compliance rate among infants, children and adults by encouraging osteopathic physicians to immunize patients of all ages when appropriate ; supports the HHS National Vaccine Implementation Plan; and encourages third- party payers to reimburse for vaccines and their administration.”
AOA on Immunizations
National Association of School Nurses
#TodaysSchoolNurse is “grounded in ethical and evidence-based practice, are the leaders who bridge health care and education, provide care coordination, advocate for quality student-centered care, and collaborate to design systems that allow individuals and communities to develop their full potential.”
“It is the position of the National Association of School Nurses (NASN) that immunizations are essential to primary prevention of disease from infancy through adulthood.
…
The school nurse is well-poised to create awareness and influence action to increase the uptake of mandated and recommended immunizations. The school nurse should use evidence-based immunization strategies, such as school-located vaccination clinics, reminders about vaccine schedules, state immunization information systems (IIS), strong vaccination recommendations, and vaccine education for students, staff, and families.”
NASN Immunizations Policy Statement
American Academy of Family Practice
“With the exception of policies which allow for refusal due to a documented allergy or medical contraindication, the AAFP does not support immunization exemption policies.”
AAFP Immunization Policy Statement
American Academy of Allergy, Asthma & Immunology
The American Academy of Allergy, Asthma & Immunology (AAAAI) is a professional organization with over 7,000 members, including allergists/ immunologists, in the United States and 73 other countries.
“Immunization is perhaps the greatest public health achievement of all time, having significantly reduced the morbidity and mortality of many infectious diseases. Routine immunization of children, adolescents, and adults provides substantial protection from a large number of infectious diseases…
Patients who have experienced adverse reactions to vaccines might unnecessarily be advised to avoid subsequent immunization, which could have important adverse personal and population health consequences. Although there are some adverse reactions to vaccines that constitute absolute contraindications to administration of future doses, most such reactions do not preclude subsequent immunization. Patients who have experienced an apparent allergic or other serious adverse reaction after receiving a vaccine warrant evaluation by an allergist/immunologist. Also, patients with preexisting health conditions that might predispose to adverse reactions to vaccines could benefit from such an evaluation. In most cases, a risk-benefit analysis will favor subsequent immunization.”
AAAAI Practice Paramater on Adverse Reactions to Vaccines
CJ First Candle
“There seems to be a common misconception that vaccines are somehow associated with SIDS deaths. This is not true! Experts warn that the risk of leaving your baby unprotected is 1,000 times greater than any increased risk for SIDS. Because infants receive many immunizations during the critical development period from two to six months of age, and 90 percent of SIDS deaths occur within this time frame, it is only logical that many SIDS victims have recently received vaccines. This does not mean that the immunization had anything to do with the infant’s subsequent sudden and unexpected death. The cause and effect of immunizations and SIDS has been comprehensively studied for more than two decades. In fact, in countries where immunization schedules are different from those in the United States, the peak incidence of SIDS is still between two to four months.”
CJ First Candle on Immunizations
Infectious Disease Society of America
Founded in 1963, the Infectious Diseases Society of America (IDSA), with over 9,000 members, represents physicians, scientists and other health care professionals who specialize in infectious diseases.
“The Infectious Diseases Society of America (IDSA) recognizes the great benefits that vaccines provide for the public health. Substantial scientific evidence demonstrates vaccines’ enormous value in protecting individuals and populations from serious and life-threatening infections. Scientific evidence also demonstrates the overall safety of vaccines. Communities are most effectively protected when all are immunized.
…
Studies demonstrate that the easier it is to receive an exemption, the higher the rate of exemptions in a particular state. As the number of exemptions increases, the risk of vaccine – preventable disease increases. Therefore, states must make every effort to minimize the number of its citizens exempted from immunization mandates. Such exemptions make the state legislatures who grant them, as well as the individuals who receive them, responsible for placing the remaining state population at greater risk of acquiring potentially fatal infections.”
IDSA Policy Statement on State Immunization Mandates
The Arc of the United States
“Prior to widespread immunization in the United States, infectious diseases killed or disabled thousands of children each year. The near elimination of intellectual disability due to measles encephalitis, congenital rubella syndrome, and Haemophilus influenzae type b meningitis or Hib can be contributed to vaccines.”
The Arc Facts About Childhood Immunizations
American College Health Association
“The American College Health Association (ACHA) strongly supports the use of vaccines to protect the health of our individual students and our campus communities. In recognition of the vital role that vaccine coverage plays in community immunity (herd immunity), ACHA discourages use of nonmedical exemptions to required vaccines.”
ACHA on Immunization Recommendations for College Students
What to Know About Expert Statements on Vaccines
Over the years, hundreds of organizations representing millions of families, health care providers, researchers, patients, and consumers, have repeatedly expressed their unequivocal support for vaccines, because they understand that vaccines work and that they are safe and necessary.
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.
The original Johns Hopkins Hospital Patient Guide did warn immunocompromised patients about contact with those who were recently vaccinated.
Are recently vaccinated people causing outbreaks of vaccine-preventable diseases?
Should kids be put in quarantine after they get their vaccines?
Of course not, but some anti-vaccine folks continue to push outdated information that hospitals, including Johns Hopkins, warn cancer patients to avoid children who were recently vaccinated.
Although vaccine shedding is a concern with some live vaccines, like the oral polio vaccine and the small pox vaccine, it is important to keep in mind that neither has been used in the United States for some time now.
Hospitals no longer warn patients about restricting exposure to people who have recently been vaccinated.
Were websites scrubbed of information about shedding as part of some conspiracy?
Of course not.
They were simply updated to keep up with the latest guidelines.
Can Immunocompromised Patients Have Visitors?
These guidelines about kids with cancer aren’t that new though.
As far back as 2001, an article in the journal Pediatrics & Child Health, “Practical vaccination guidelines for children with cancer,” recommended that household contacts of immunosuppressed children should receive:
all routine, age-appropriate vaccines, including DTaP, IPV, Hib, MMR, and Tdap, and that no special precautions are necessary because transmission of disease from these vaccines does not occur.
the varicella vaccine and that even in the event of a vaccine-associated vesicular rash, the transmission risk is low and the consequences of infection are limited by the attenuated nature of the vaccine virus.
These recommendations for household contacts of immunosuppressed children are based on the 2000 Red Book: Report of the Committee on Infectious Diseases.
The recommendations in latest (2012) edition of the Red Book state that household contacts of people with an immunologic deficiency should also:
receive either the inactivated influenza vaccine or live attenuated influenza vaccine, giving preference to the inactivated influenza vaccine only if the immunosuppressed person is a hematopoietic stem cell transplant (HSCT) recipient in a protected environment.
The revised Johns Hopkins Hospital Patient Information Guide no longer warns about contact with children who were recently vaccinated.
So hospitals should no longer be warning patients about restricting exposure to people who have recently been vaccinated.
In fact, the latest guidelines from the Immune Deficiency Foundation Advisory Committee state that except for the live oral poliovirus vaccine, close contacts can receive other standard vaccines because viral shedding is unlikely and these pose little risk of infection to a subject with compromised immunity.
The Immune Deficiency Foundation also warns that, “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.”
In other words, they are concerned about the risk of disease from intentionally unvaccinated kids and not from those who were recently vaccinated!
So, what about visitors?
“Tell friends and family who are sick not to visit. It may be a good idea to have visitors call you first.”
The Johns Hopkins Hospital Patient Information Guide
Although you can’t prevent every cough and cold that might keep you from visiting a friend or family member who is being treated for cancer or has another immune system problem, keeping up to date on all vaccines can help to make sure that you don’t spread a vaccine-preventable disease, like measles or chickenpox, to them.
What To Know About The Johns Hopkins Vaccine Warning
Not only is Johns Hopkins Medical Center not telling cancer patients to avoid contact with children who recently received vaccines, they have gone out of their way to correct that misinformation from anti-vaccine websites.
Johns Hopkins Medicine, which includes the Johns Hopkins University School of Medicine and the The Johns Hopkins Hospital and Health System went out of their way to correct this anti-vaccine misinformation.
Some folks haven’t gotten the message though and continue to push the idea that Johns Hopkins and other Hospitals warn cancer patients to avoid contact with recently vaccinated children.
