5/8/15

What is Herd Immunity and can Mass Vaccination Acheive it?

    The herd immunity theory was first suggested by researcher A.W. Hedrich in the early 1900’s.1 During his observations of measles outbreaks in the city of Baltimore, Hedrich noted that when 68% of children under the age of fifteen had developed natural immunity to measles, outbreaks in the community stopped.1 The idea behind Hedrich’s theory is that when a pre-calculated percentage of a population is immune to a disease, the disease is unable to gain a foothold and spread through the population.1

    Vaccine proponents later adopted Hedrich’s theory and used it to predict epidemiological patterns in vaccinated populations.2 This seemed simple enough at first but as it turns out, there are significant differences between natural immunity and vaccine-induced immunity that scientists were not aware of at the beginning of widespread vaccination programs.2

    The vaccination rate supposedly necessary to achieve the desired herd immunity threshold is under endless revision as scientists and health authorities are forced to confront the reality that vaccination is not immunization. Though the terms are often used interchangeably, vaccination and immunization are two distinctly different processes.3

    “You can be vaccinated, but if there is no immunity, you are not immunized. You can be unvaccinated, but if you have had the disease and have protection, you are immune; therefore you are immunized.”[emphasis mine]3

    If vaccination were equivalent to immunization, the CDC’s so-called “Immunization Schedule” would not need a growing succession of “booster shots” in order to establish protection. Moreover, we would not see vaccinated individuals constituting a high proportion of those affected during disease outbreaks.

Inability of Acellular Pertussis Vaccination to Establish Herd Immunity

    Despite high DTaP uptake (the vaccine supposed to protect against diphtheria, tetanus and pertussis), in 2012, the United States saw a 50-year high in pertussis incidence, with fully-vaccinated individuals constituting a high proportion of pertussis cases.4  In the following year, researchers for the FDA hypothesized that acellular pertussis vaccines (the only kind currently approved for use in the U.S.) do not prevent colonization and transmission of pertussis. The FDA later issued a press announcement stating that an in-house study had confirmed their hypothesis: acellular pertussis vaccines cannot prevent infection and transmission of the bacterial pathogen that causes pertussis. 4 5  This means that the only known benefit of current pertussis vaccines is that they can minimize pertussis symptoms. For this reason, however, pertussis vaccination is arguably more dangerous to ‘the herd’ than the unvaccinated since those who have been vaccinated are less likely to experience clinical symptoms of infection, and thus less likely to be aware if they are contagious.  

    Perhaps even more concerning is the association of acellular pertussis vaccination with the rise of B. parapertussis. A 2010 study revealed that DTaP vaccination interferes with optimal clearance of B. parapertussis, a mutated version of the pertussis bacteria, for which there is currently no vaccine.6 In 2013, a meeting of the Board of Scientific Counselors at the CDC confirmed this finding, stating that patients who are up-to-date on DTaP shots “had significantly higher odds than unvaccinated patients” of becoming infected with other strains of pertussis bacteria, suggesting that pertussis strains currently circulating in the U.S. have gained a selective advantage to infect the vaccinated.7 8

    Undeterred by these crucial findings, the CDC still boldly asserts that “pertussis can be prevented with vaccines” and even recommends routine vaccination of pregnant women, claiming that pertussis vaccination can protect mothers during delivery, making them less likely to transmit pertussis to their infants.” 9 At best, this portrayal of pertussis vaccine benefits is offhandedly misleading. At worst, the CDC is intentionally misrepresenting the benefits of pertussis vaccines in favor of current vaccine policies.

    To be fair, it is possible that pertussis vaccination during pregnancy could confer some level of protection to the infant during the first weeks of life via passive antibody transfer, but the duration and effectiveness of maternal vaccination to protect infants has not been well established. Very little is known about the effects the vaccine could have on pregnant women and developing fetuses. The CDC still maintains that any “theoretical” risk to mother and baby is outweighed by the benefits of the vaccine.9  

    To further complicate matters, the CDC estimates that only 70 percent of those who have received the entire 5-dose DTaP regimen are “fully protected” just 5 years after their last shot.9  As current pertussis vaccines have been proven ineffective at preventing infection and transmission of pertussis, one has to wonder what it could possibly mean to be “fully protected” by pertussis vaccines? Even if these vaccines were capable of preventing pertussis infection, as per the CDC’s own estimates, anyone over the age of 11 who hasn’t had a booster shot is likely unprotected. 9  

    In summary, acellular pertussis vaccines (DTaP and Tdap) are ineffective at preventing infection and transmission of pertussis. Therefore, the only known benefit of these vaccines is that they may render personal protection from severe pertussis symptoms. This protection is temporary, however, with many vaccinees losing protection just 5 years after their last shot. The pertussis booster is only protective for around 2 years and is only recommended once per lifetime unless pregnant. That is, the same booster shot that is only effective for 2 years and only recommended once per lifetime is currently recommended during every pregnancy. Let that sink in for a moment…

   
For all of the reasons above, current pertussis vaccines are not capable of establishing herd immunity. Even so, herd immunity-based arguments continue to be used to justify mandatory DTaP compliance of school children and encourage booster shots for adults and pregnant women.

    It should also be noted that the concept of herd immunity does not bear equal relevance to every “vaccine-preventable disease.” Tetanus (a component of DTaP and Tdap vaccines), for example, is not a communicable disease and therefore, tetanus vaccination cannot affect herd immunity.8

Vaccines Vs. Natural Disease in Establishing Herd Immunity

    The original herd immunity theory was developed based on observations of a naturally immune population in which immunity was lifelong. Given that the protection afforded by vaccines is temporary at best, many doctors and scientists now recognize that the herd immunity theory cannot be applied to vaccinated populations with the expectation of parallel results
.  Nevertheless, public health officials continue to use the theory to justify mandatory vaccinations (especially among school-aged children) despite the fact that even 100 percent vaccine uptake among children is not capable of establishing and maintaining herd immunity for the entire population.10  

    If vaccines do not provide lifelong immunity, and some vaccines cannot prevent infection and transmission of the diseases they’re intended to prevent, what are the implications for the herd immunity threshold public health officials claim is absolutely essential for preventing devastating epidemics? Retired neurosurgeon, Dr. Russell Blaylock remarks in a 2012 article,

“That vaccine-induced herd immunity is mostly myth can be proven quite simply. When I was in medical school, we were taught that all of the childhood vaccines lasted a lifetime. This thinking existed for over 70 years. It was not until relatively recently that it was discovered that most of these vaccines lost their effectiveness 2 to 10 years after being given. What this means is that at least half the population, that is the baby boomers, have had no vaccine-induced immunity against any of these diseases for which they had been vaccinated very early in life. In essence, at least 50% or more of the population was unprotected for decades…If we listen to present-day wisdom, we are all at risk of resurgent massive epidemics should the vaccination rate fall below 95%. Yet, we have all lived for at least 30 to 40 years with 50% or less of the population having vaccine protection. That is, herd immunity has not existed in this country for many decades and no resurgent epidemics have occurred.” 2 [emphasis mine]
   
   
Using sophisticated mathematical and epidemiological models, a 2009 study by Heffernan et al. demonstrates that while mass-vaccination programs have the effect of decreasing the prevalence of infectious diseases initially, due to waning vaccine immunity and a decline in “boosting effects’ that occur during cyclical re-exposure to disease, large-scale epidemics will occur sometimes as long as 52 years after the vaccination program was begun.11 [emphasis mine]

    Heffernan et al observe,

“In the absence of vaccination, lifelong immunity is maintained through frequent encounters with infection, which act to boost the waning immune memory…However, when vaccination is introduced the prevalence of infection declines, which in turn reduces the amount of boosting and hence the level of immunity…What is more surprising is that the interaction between vaccination and waning immunity can lead to pronounced epidemic cycles in which the peak levels of infection can be of the orders of magnitude greater than the mean.”11 [emphasis mine]

    It can thus be argued that mass-vaccination actually undermines herd immunity, leaving a population more vulnerable to infectious diseases than it had been prior to vaccination programs. Dr. Tetyana Obuckanych further explains that while mass-vaccination programs geared towards children have been shown to achieve rapid reduction of disease at first, this is “only because it hitch hikes on top of the permanently immune majority of adults who acquired their immunity naturally in the pre-vaccination era.”10

    With a diminishing proportion of naturally immune adults, the only way to maintain true herd immunity via vaccination will be to vaccinate 100 percent of the population (including adults and the elderly) as often as is needed to maintain protective antibody levels in the majority of the population. Vaccine-induced herd immunity for some diseases would require booster shots every 2-5 years for everyone in the population who is vaccine-eligible. According to the CDC, there are very few actual precautions and contraindications to most vaccines and many of these are only temporary.12 This means that the majority of the population would be considered “vaccine-eligible” and thus required to receive an indeterminate number of booster shots for every “vaccine-preventable disease” in order to maintain protective antibody titers in the majority.

    True herd immunity from vaccines would necessarily require government-mandated, lifelong vaccine programs targeted at the entire population with very few exceptions. If vaccines were perfectly safe, perhaps such a rigorous vaccine schedule for the entire population wouldn’t be a problem. But as is evidenced by every vaccine product insert and the tax-payer-funded Vaccine Injury Compensation Program, vaccines are not near safe enough to justify mandatory compliance of the entire population with such a schedule. Furthermore, the observation that true herd immunity has not existed in the U.S. for decades and no devastating epidemics have occurred gives cause for serious doubts about its necessity.

    References:

1.       http://vaccinechoicecanada.com/about-vaccines/general-issues/herd-immunity/herd-immunity-the-misplaced-driver-of-universal-vaccination/

2.       http://www.vaccinationcouncil.org/2012/02/18/the-deadly-impossibility-of-herd-immunity-through-vaccination-by-dr-russell-blaylock/

3.       Humphries, MD and Bsytrianyk. (2013). Dissolving Illusions

4.       http://www.ncbi.nlm.nih.gov/pubmed/24277828

5.       http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm376937.htm

6.       http://rspb.royalsocietypublishing.org/content/277/1690/2017

7.       http://www.cdc.gov/maso/facm/pdfs/BSCOID/2013121112_BSCOID_Minutes.pdf

8.       http://www.thepeoplesvoice.org/TPV3/Voices.php/2015/04/30/harvard-trained-immunologist-demolishes-

9.       http://www.cdc.gov/pertussis/about/faqs.html

10.   http://www.naturalimmunityfundamentals.com/herdimmunity

11.   http://rspb.royalsocietypublishing.org/content/276/1664/2071

12.   http://www.cdc.gov/vaccines/pubs/pinkbook/genrec.html

13.   http://www.hrsa.gov/vaccinecompensation/index.html

 

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