Routine vaccination with smallpox vaccines ended in the US in 1972, a short time before smallpox was declared eradicated (1980).
It was also before the last case of wild smallpox was found (1977).
Because smallpox had been declared eliminated in North America long before (1952), following the last natural outbreak of smallpox in the United States (1949).
Should I Be Worried That My Kids Didn’t Get the Smallpox Vaccine?
Although smallpox has been eradicated, some folks still worry about it.
“There are now only two locations where variola virus is officially stored and handled under WHO supervision: the Centers for Disease Control and Prevention in Atlanta, Georgia, and the State Research Center of Virology and Biotechnology (VECTOR Institute) in Koltsovo, Russia.”
CDC on History of Smallpox
Of course, the concern now is not naturally occurring smallpox, but instead bioterrorism.
Could the smallpox virus be made into a weapon to be used in a bioterrorist attack?
We hope not, but if it was, none of us would be immune, not even the folks who were vaccinated long ago. The smallpox vaccine doesn’t provide life-long immunity.
So should you be worried?
“Some people have been vaccinated through the military or because they were part of Smallpox Response Teams that were formed after the 9/11 terrorist attacks.”
CDC on Why is Smallpox a Concern?
Almost certainly not.
Plans are in place if there ever was a smallpox attack and if necessary, there is actually enough smallpox vaccine stockpiled to vaccinate everyone in the United States!
You want some time for it to start working, so that you can be sure that you are protected.
So while some folks talk about getting a flu vaccine too early, you do want to make sure that you get it in time to get protection before flu is active in your area. Still, it is never too late to get a flu vaccine. It is better to get a flu vaccine late in the flu season than to skip it all together.
What about younger kids getting their flu vaccine for the first time and who need 2 doses? When do they start getting protection?
“The first dose “primes” the immune system; the second dose provides immune protection.”
Study Looks at Flu Vaccine Dosing in Children
Although they likely have some protection after that first dose, the best protection will begin 10 to 14 days after their second dose.
What are those exactly? That the protection babies get from their mother’s pregnancy flu shot doesn’t last until they go to college?
What’s the greatest evidence that they might not support vaccines? I mean, besides anti-vaccine La Leache League leaders who actively say that they are against vaccines?
Bob Sears is giving two lectures on vaccines at an upcoming La Leche League breastfeeding conference.
Will he really discuss the benefits of vaccines for pregnant and post-partum mothers and their families?
“Dr. Bob Sears, a renowned Dana Point pediatrician who has been sought out by parents who wish to opt out of the state’s mandatory vaccine requirements, has been placed on probation for 35 months by the Medical Board of California.”
Dr. Bob Sears, renowned vaccine skeptic, placed on probation for exempting child from all vaccinations
“Remember that La Leche League is exclusively focused on breastfeeding support and has no stance on vaccinations.”
La Leche League USA
No stance on vaccinations?
Actually, with bringing Dr. Bob to their conference, it seems like they made a very clear stance…
“Nursing also allows your baby to give germs to you so that your immune system can respond and can synthesize antibodies! This means that if your baby has come in contact with something which you have not, (s)he will pass these germs to you at the next nursing; during that feeding, your body will start to manufacture antibodies for that particular germ. By the time the next feeding arrives, your entire immune system will be working to provide immunities for you and your baby. If you are exposed to any bacteria or viruses, your body will be making antibodies against them and these will be in your milk.”
Can Breastfeeding Prevent Illnesses?
And they have also done a good job of making it sound like breastfeeding infants don’t need vaccines.
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
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.
Taken together, you have to say that vaccines work very well.
Remember, according to the CDC:
Vaccine efficacy/effectiveness (VE) is measured by calculating the risk of disease among vaccinated and unvaccinated persons and determining the percentage reduction in risk of disease among vaccinated persons relative to unvaccinated persons. The greater the percentage reduction of illness in the vaccinated group, the greater the vaccine efficacy/effectiveness.
They aren’t perfect though and some vaccines do work better than others.
For example, the MMR vaccine provides 99% protection (two doses) against measles, while the seasonal flu vaccine can vary from 10% to 60%, depending on how well the flu vaccine matches the flu virus strains that are getting people sick that year.
Fortunately, most vaccines have over 90 to 95% effectiveness.
The exceptions, in addition to flu vaccines, are the mumps and pertussis vaccines.
In addition to problems with waning immunity, they have lower rates of effectiveness than most other vaccines:
That’s probably why we are seeing more outbreaks of mumps and pertussis among vaccinated children and young adults, although intentionally unvaccinated children and adults are also contributing to most of those outbreaks.
For More Information On Efficacy Rates of Vaccines: