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Readers are encouraged to go to the websites of the U.S. Department of Health and Human Services (DHHS) for the perspective of federal agencies responsible for vaccine research, development, regulation and policymaking, including the U.S. Centers for Disease Control (CDC) for information on vaccine policymaking; to the U.S. Food and Drug Administration (FDA) for information on regulating vaccines for safety and effectiveness; and to National Institutes of Health’s National Institute of Allergy and Infectious Diseases (NIAID) for information on research and the development of new vaccines.
The World Health Organization has stated that “vaccine hesitancy” is one of the top 10 global public health threats.
I recently wrote about the renewed calls for state legislatures to eliminate personal belief vaccine exemptions and restrict medical exemptions, and how California state Sen. Dr. Richard Pan, D-Sacramento, is even urging the U.S. Surgeon General to push mandatory vaccinations to the top of the federal public health agenda.1,2
According to Pan, “unwarranted vaccine hesitancy” is a threat to public health as it prevents “community immunity, which protects our children and the most vulnerable.” He believes mandating vaccines, as was done for smallpox during the Revolutionary War, would “protect our right as Americans to be free of preventable diseases.”
Herd Immunity and Vaccination
What he’s talking about is achieving and maintaining so-called vaccine-acquired “herd immunity,” the theory which maintains that once a majority of people have been vaccinated, the infectious disease in question can no longer spread and everyone is protected, including the tiny minority who for whatever reason are not or cannot be vaccinated.
The problem with this argument is that it doesn’t work for vaccines. While there is such a thing as herd immunity among populations in which a majority has had the infectious disease and acquired a long lasting natural immunity, vaccines confer only temporary artificial immunity, and so true herd immunity is unlikely to be fully achieved, even if nearly 100 percent of the population are vaccinated.
The measles vaccine, for example, wears off after about a decade3 or two. 4,5 Whatever temporary artificial protection is obtained from other vaccines also fades in time. If you are an adult, chances are that some of the vaccinations you received as a child are not protecting you today.6 What’s more, between 2 and 10 percent of some vaccines result in “primary vaccine failure,” meaning those who get the vaccine do not gain even temporary artificial protection after vaccination. 7
Indeed, public health officials are now recommending adults born in or after 1957 to get revaccinated against measles.8,9,10 Since the Disneyland-related measles outbreak in early 2015, some public health doctors are even suggesting all adults should get a measles-mumps-rubella (MMR) booster shotbecause as many as 1 in 10 previously vaccinated adults may be susceptible to measles due to waning vaccine-acquired immunity.11
Herd Immunity Does Not Work for Measles
It’s quite possible that revaccinating adults still would not achieve herd immunity for measles. Dr. Alexander Langmuir is known as “the father of infectious disease epidemiology.” In 1949, he created the epidemiology section of what became the U.S. Centers for Disease Control and Prevention (CDC). He also headed the Polio Surveillance Unit founded in 1955 after polio vaccine safety issues became public.
According to Langmuir and many other experts, one dose of the measles vaccine was supposed to eradicate the common childhood disease. But, of course, that did not happen.
By the early 1980s, more than 95 percent of children entering school in the U.S. had received a dose of measles containing vaccine but, in 1989-1990, there were outbreaks of measles among school-age children and college students. Public health officials responded by recommending a second dose of MMR vaccine for all children. In an article published in Clinical Microbiology Reviews in 1995, researchers stated:
“Measles, which was targeted for elimination from the United States in 1979, persisted at low incidence until 1989, when an epidemic swept the country. Cases occurred among appropriately vaccinated school-age populations and among unimmunized, inner-city preschool children.
In response to the epidemic, measles immunization recommendations have been modified. To prevent spread among school-age populations, a second dose of MMR vaccine is recommended at 5 to 6 or 11 to 12 years of age.”12
A 1994 study13 looking at measles incidence in Cape Town, Africa, indicated that as vaccination rates increased, measles became a disease in populations where the majority of children had been vaccinated. The immunization coverage was 91 percent and vaccine efficacy was estimated to be 79 percent. According to the authors:
“The epidemiology of measles in Cape Town has thus changed as evinced in this epidemic, with an increase in the number of cases occurring in older, previously vaccinated children. The possible reasons for this include both primary and secondary vaccine failure.”
This “startling” surprise challenged the theory that vaccine-induced herd immunity would provide complete protection against outbreaks of measles. The CDC has also admitted, and reports in the medical literature have documented, that measles outbreaks occur both in highly vaccinated school populations and among vaccinated adult populations.14, 15,16 ,17,18,19,20,21,22
Examples of Measles Outbreaks in Highly Vaccinated Populations
A recent example of measles outbreaks in a highly vaccinated population occurred in Israel in 2017 in a military population ranging in age from 19 to 37, which had “high measles vaccination coverage.” The first two patients identified had both received two doses of measles vaccine. Patient zero, a 21-year-old soldier, had documentation of having received three doses. According to the CDC:23
“All patients except one had high measles IgG avidity, which is an indicator of previous vaccination or previous infection. Because all the serum specimens (except that from the primary patient) were collected two to three days after the onset of symptoms, the high avidity IgG was assumed to be a result of patients’ previous vaccination.
Although outbreaks of measles among vaccinated populations have been reported worldwide,24,25,26,27 most outbreaks in Israel have occurred in unvaccinated or partially vaccinated populations).
Measles transmission from a vaccinated person with documented secondary vaccine failure also has been described in New York City in 2011, including among vaccinated health care providers,28 and in the Marshall Islands.29 Waning of vaccine-induced immunity is a phenomenon that needs to be addressed …”
Another example is a 2014 study30 conducted in the Zhejiang province in China. Researchers found that populations which have achieved a measles vaccination rate of 99 percent through mandatory vaccination programs are still experiencing consistent outbreaks far beyond what the World Health Organization expects.
What’s more, 93.6 percent of the 1,015 participants in this study tested seropositive for measles antibodies, which theoretically means they should have been protected against the disease.
The herd immunity threshold for vaccine-acquired artificial immunity is thought to be between 80 and 95 percent,31 depending on the disease in question (for measles, it’s 90 to 95 percent) yet, even though 94 percent of individuals had antibodies against measles in this case, an outbreak still occurred.
Persistent reports of measles and other infectious diseases for which vaccines have been developed and given in multiple doses to most children calls the concept of vaccine-acquired herd immunity into question.
Natural Versus Vaccine-Induced Immunity
Again, a key factor to consider is that many vaccines do not provide long-lasting or lifelong immunity. Vaccines only confer temporary artificial immunity and sometimes they fail to do that. This has been shown to have important generational ramifications as well. Infants under age 1, who used to be protected in the first year of life by getting natural maternal antibodies from their mothers, who had experienced and recovered from measles in childhood, are now susceptible to measles from birth.
That is because most young mothers today have been vaccinated and measles vaccine-acquired maternal antibodies are far less protective than naturally acquired antibodies.32,33 To understand why this is so, you need to understand a little bit about how your immune system works.
There are two systems that fight disease in your body. One is the innate system that is always ready to work and the other is the adaptive arm of immunity. The adaptive arm consists of Th1 and Th2. Both are necessary but Th1 is commonly known as the cell mediated arm, and Th2 known as the humoral or antibody arm.
Most vaccines preferentially stimulate the Th2 or humoral part of the immune system. Measured antibodies in the blood (antibody titers) may be reflective of partial immunity, but it is not a perfect correlate to full immunity that involves both innate (cellular) and humoral (adaptive) immune responses, such as those obtained after recovery from viral or bacterial infections.