Vaccines
Text size:
Understanding the Rationale Behind Vaccines
Published February 18, 2016 | Vaccination, Vaccines
Story Highlights- The prevailing assumption within the medical, government, pharmacology and science communities is that vaccines are safe and effective.
- Those who question that foundation are said to be relying on quack science.
- To have a open conversation about the potential dangers of vaccination, we must understand the science behind vaccines.
The frantic push to develop a Zika vaccine—before it has even been established that the usually mild Zika infection is actually behind the upsurge in cases of microcephaly among newborns in Brazil—is a prime example of that deeply held belief. But how much is truly understood about vaccines or the vaccination process?
What Medical Schools Teach
It is a common argument that only quacks looking to discredit the medical field would claim that doctors do not have a basic understanding about vaccination, because someone who has gone through medical school has spent many hours learning about the immune system:Without even counting the related fields of physiology, the respiratory system, gastroenterology, histology, neurology, etc., I came up with 920 hours of graduate education in immunology, microbiology, and infectious disease.1and…
If we presume that my (rather average) medical school was representative, then most doctors spend ~ 920 hours in graduate education in this field before ever being allowed to sit for the Step I Board Exam.1But because the underlying assumption is that, “decades of research from hundreds of medical, government and nonprofit organizations around the world have proven time and time again that vaccines are safe and effective,”2 there is very little taught in medical schools about vaccination itself, aside from its accepted role as a hero of public health programs.
The foundation of belief is such that it isn’t considered necessary to examine the science behind vaccines, the rationale for vaccinating, the steps or ingredients involved in creating a vaccine, how vaccination stimulates artificial immunity, or the ways in which vaccination affects the immune system as a whole. For medical doctors teaching prospective doctors in medical schools about vaccination, it has been enough to say that vaccines are necessary, safe and effective.
As Bob Sears, MD writes,
Doctors, myself included, learn a lot about diseases in medical school, but we learn very little about vaccines, other than the fact that the FDA and pharmaceutical companies do extensive research on vaccines to make sure they are safe and effective. We don’t review the research ourselves. We never learn what goes into making vaccines or how their safety is studied. We trust and take it for granted that the proper researchers are doing their job. So, when patients want a little more information about shots, all we can really say as doctors is that the diseases are bad and the shots are good.3Suzanne Humphries, MD said,
When we participate in pediatrics training, we learn that vaccines need to be given on schedule. We learn that smallpox and polio were eliminated by vaccines. We learn that there’s no need to know how to treat diphtheria, because we won’t see it again anyway. We are indoctrinated with the mantra that ‘vaccines are safe and effective’ —neither of which is true.4
What Do We Know About How Vaccines Are Created?
First, there are several types of vaccines:5Live virus vaccines are made up of attenuated, or weakened strains of the microbe. In the case of an attenuated vaccine, the virus is “passed through” a host cell (such as a chick embryo cell line) over and over. With each pass, the virus becomes more adept at replicating in the host cell but less able to proliferate in human cells, so less likely to cause illness.
Examples of live virus vaccines include measles, mumps, and rubella (MMR), varicella (chickenpox), rotavirus, and the nasal spray influenza vaccine, as well as zoster (shingles) and yellow fever vaccines. One of the dangers with a live attenuated vaccine is the possibility that the weakened virus strain may mutate to a more dangerous form after it is shed in body fluids of a recently vaccinated person, as has occurred with the live oral polio vaccine (OPV).
Globally, widespread use of OPV has caused vaccine strain polio paralysis in children and adults and contamination of sewage and water supplies with mutated vaccine strain poliovirus. There is evidence that most live virus vaccines can cause vaccine strain infection, shedding and transmission of vaccine strain virus.6 The U.S. stopped using OPV in 1999 and now uses an inactivated, injectable polio vaccine (IPV) that cannot cause vaccine strain polio.
Inactivated or killed bacterial and viral vaccines have traditionally been created using either heat, chemicals or radiation to inactivate the bacteria or virus and, today, genetic engineering technology is also being used. Inactivated vaccines are more stable than live virus vaccines because the dead microbe cannot cause vaccine strain infection, shedding and transmission like live virus vaccines. However, any protection inactivated vaccines offer to the vaccinated person is also weaker, so it is shorter-acting and usually require booster shots.
Inactivated bacterial and viral vaccines are also likely to include an adjuvant, which is added to stimulate the immune system to mount a stronger inflammatory response that is supposed to provide longer lasting vaccine immunity. Inactivated vaccines packaged in multi-dose vials many also include a preservative to prevent bacteria, fungi and other microbes from contaminating it.
Examples of inactivated vaccines used in the U.S. include pertussis (included in DPT/DTaP/Tdap vaccines), killed polio (IPV), injectable influenza, hepatitis A and rabies.
Toxoid vaccines are designed for use against infections in which the toxins produced by the bacteria, rather than the bacteria itself, cause illness. A toxoid vaccine uses the toxin, which is inactivated with heat or a chemical, such as formalin. Toxoid vaccines include tetanus and diphtheria, typically combined with pertussis, such as in DPT vaccine
Submit and conjugate vaccines include antigens that are thought to best stimulate an immune response, such as isolated proteins from the microbe, rather than the whole microbe. Like inactivated and toxoid vaccines, subunit and conjugate do not cause vaccine strain infection, shedding and transmission of the lab-altered microbe, as is the case with live virus vaccines. Examples of subunit vaccines include the inactivated injected form of the influenza vaccine, Haemophilus influenza type b (Hib), and acellular pertussis (included in the combination DTaP/Tdap vaccines).
Genetically engineered recombinant vaccines are another type of subunit vaccine and are made by using in which the microbe’s genes that code for important antigens to stimulate an inflammatory immune response. For example, to make the recombinant hepatitis B vaccine, scientists inserted hepatitis B genes into common baker’s yeast and the yeast produced the antigens that were collected and purified for inclusion in the vaccine.7 Genetic engineering was also used to create the human papilloma virus (HPV) vaccine, employing a slightly different process that created virus like protein particles (VLPs) designed to stimulate vaccine immunity.
The bacterial conjugate vaccines are similar to recombinant vaccines but use pieces of an outer coating of sugar molecules from a bacterium (polysaccharides) linked to antigens or toxoids from the microbe. Examples of conjugate vaccines include Haemophilus influenza B (HIB), pneumococcal and meningococcal vaccines.
Experimental DNA and recombinant vector vaccines are in development. Scientists creating DNA vaccines take the genes from a microbe and use them to code for the microbe’s antigens. DNA vaccines will insert microbe DNA directly into cells of the body to stimulate an inflammatory immune response.
Recombinant vector vaccines are similar to DNA vaccines, but use a bacterium or attenuated virus to introduce microbial DNA into cells of the body. The virus or bacterium is used as a vector or “carrier” to deliver the microbial DNA. Because recombinant vector vaccines are designed to more closely mimic natural infection, they provoke a strong immune response.8
Vaccine Components
There are several components to vaccines, identified as antigens, stabilizers, adjuvants, antibiotics, and preservatives, and reviewed below as described by the World Health Organization (WHO)9 (Not all vaccines include all of these components). The vaccine product manufacturer insert that accompanies vials of vaccines administered in private doctor offices or public health clinics are required by U.S. law to list vaccine ingredients (see Diseases and Vaccines pages on NVIC.org to read or download vaccine manufacturer product inserts).
Antigens
The foundation of a vaccine is the antigen itself, defined as “any substance that causes your immune system to produce antibodies against it… An antigen may be a substance from the environment, such as chemicals, bacteria, viruses, or pollen. An antigen may also form inside the body.”10 The antigen is the segment of the disease organism that is recognized as “foreign” (non-self) by the body’s immune system and thus activates the inflammatory response.
The foundation of a vaccine is the antigen itself, defined as “any substance that causes your immune system to produce antibodies against it… An antigen may be a substance from the environment, such as chemicals, bacteria, viruses, or pollen. An antigen may also form inside the body.”10 The antigen is the segment of the disease organism that is recognized as “foreign” (non-self) by the body’s immune system and thus activates the inflammatory response.
Adjuvants
Substances known to provoke an inflammatory response are added to vaccines, especially those using an inactivated or “killed” antigen, to ensure a powerful immune system response to the vaccine, specifically to the co-administered antigen. WHO notes that some of the newer types of vaccines (purified subunit or synthetic vaccines) “require adjuvants to provoke the desired immune response.”
Substances known to provoke an inflammatory response are added to vaccines, especially those using an inactivated or “killed” antigen, to ensure a powerful immune system response to the vaccine, specifically to the co-administered antigen. WHO notes that some of the newer types of vaccines (purified subunit or synthetic vaccines) “require adjuvants to provoke the desired immune response.”
Further,
WHO says adjuvants “are highly variable in terms of how they affect the
immune system and how serious their adverse reactions are, due to the
resulting hyperactivation of the immune system.” Worldwide, there are
many different adjuvants either currently in use, or being studied for
addition to future vaccines.11
In the U.S. and most other countries, however, the most commonly used vaccine adjuvants, at least in human vaccines, are aluminum-based (alum) and
squalene (oil in water). Aluminum adjuvants are found in hepatitis A,
hepatitis B, diphtheria-tetanus-pertussis (DTaP, Tdap), Haemophilus
influenzae type b (Hib), human papillomavirus (HPV) and pneumococcal
vaccines.
Unfortunately,
there are a number of problems with alum. First, although it does
provoke a strong inflammatory response that stimulates antibody
production, it does little to induce the cellular response necessary for
long lasting protection.12 Aluminum
adjuvants have also been associated with severe local and systemic side
effects, including sterile abscesses, eosinophilia, and myofascitis,
and there is some concern that aluminum may play a role in developmental
delays, autoimmune and neurodegenerative diseases, including
Alzheimer’s disease.13
Squalene is
a polyunsaturated hydrocarbon found in plants, animals and humans. The
human liver manufactures small amounts of squalene that circulates in
the bloodstream, but squalene is most abundantly found in the livers of
deep sea sharks and is used in the manufacture of pharmaceutical drugs,
cosmetics and foods. Emulsions of squalene with surfactants (like
Polysorbate 80) are added to some vaccines in an effort to stimulate a
strong inflammatory response in the body that leads to production of
antibodies.14 Squalene and other types of squalene-like (oil in water) vaccine adjuvants (ASO3, MF-59) have been associated with serious autoimmune disorders in humans.15 16 17
The Novartis Fluad influenza vaccine recently licensed by FDA for seniors contains a squalene adjuvant (MF59). An emergency stockpiled pandemic influenza A (H5N1) vaccine has been licensed that contains AS03, but it is not commercially available. The HPV vaccine, Cervarix, contains AS04, an adjuvant that is a combination of aluminum hydroxide and a purified fat-like substance, monophosphoryl lipid A (MPL).
Adjuvants
are not included in the live virus measles, mumps, rubella, chickenpox,
rotavirus, polio, and influenza vaccines, where the weakened live virus
provokes an inflammatory response in the body that more closely
resembles the body’s natural response to the wild-type virus, which
stimulates both cellular and humoral immunity.18
Stabilizers
Stabilizers are added to preserve effectiveness of the vaccine, especially where the “cold chain” cannot be guaranteed. Instability in a vaccine can be caused by several factors, including changes in temperature or pH values and can interfere with the potency or actions of the vaccine. Common stabilizers include MgCl2 (for the oral polio vaccine), MgSO4 (for measles), lactose-sorbitol, and sorbitol-gelatine.
Stabilizers are added to preserve effectiveness of the vaccine, especially where the “cold chain” cannot be guaranteed. Instability in a vaccine can be caused by several factors, including changes in temperature or pH values and can interfere with the potency or actions of the vaccine. Common stabilizers include MgCl2 (for the oral polio vaccine), MgSO4 (for measles), lactose-sorbitol, and sorbitol-gelatine.
Antibiotics
Antibiotics may be used during the vaccine manufacturing process to prevent contamination of the vaccine by bacteria that may have been present in the virus growth cultures. Though very small amounts of antibiotics are in some vaccines, WHO cautions that, for example, “Persons who are known to be allergic to neomycin [for example] should be closely observed after vaccination so that any allergic reaction can treated at once.”19 Other antibiotics, such as neomycin, polymixin B, streptomycin and gentamycin, are also found in trace amounts in different vaccines.
Antibiotics may be used during the vaccine manufacturing process to prevent contamination of the vaccine by bacteria that may have been present in the virus growth cultures. Though very small amounts of antibiotics are in some vaccines, WHO cautions that, for example, “Persons who are known to be allergic to neomycin [for example] should be closely observed after vaccination so that any allergic reaction can treated at once.”19 Other antibiotics, such as neomycin, polymixin B, streptomycin and gentamycin, are also found in trace amounts in different vaccines.
Preservatives
Preservatives in inactivated vaccines today are primarily found in “multi-dose” vials that are (designed to hold multiple doses of vaccine withdrawn from the vials with syringes to be administered to more than one person. Preservatives are added to help prevent any bacterial or fungal cross contamination that could occur when syringes are inserted multiple times into the vial to withdraw vaccine for each person. Preservatives also help protect against the growth of any toxic microorganisms during the manufacturing process.
Examples of the types of
preservatives used in vaccines include the mercury compound, Thimerosal,
as well as formaldehyde and phenol derivatives. Single-dose vials
(those designed for use one time, on one person) generally do not
require preservatives, although there may be trace amounts of
preservatives in single dose vials of vaccine left over from the
manufacturing process.Preservatives in inactivated vaccines today are primarily found in “multi-dose” vials that are (designed to hold multiple doses of vaccine withdrawn from the vials with syringes to be administered to more than one person. Preservatives are added to help prevent any bacterial or fungal cross contamination that could occur when syringes are inserted multiple times into the vial to withdraw vaccine for each person. Preservatives also help protect against the growth of any toxic microorganisms during the manufacturing process.
Excipients
Vaccine ingredients considered to be inactive or inert are defined as excipients, although there is disagreement about which vaccine ingredients should be classified as excipients without biological effects. Unfortunately, most vaccine ingredients have never been tested separately for safety when given separately or co-administered.
Vaccine ingredients considered to be inactive or inert are defined as excipients, although there is disagreement about which vaccine ingredients should be classified as excipients without biological effects. Unfortunately, most vaccine ingredients have never been tested separately for safety when given separately or co-administered.
Vaccine
ingredients that have been labeled as excipients include trace amounts
of preservatives, stabilizers or substances left behind during the
vaccine manufacturing process. However, certain vaccine ingredients
sometimes categorized as “excipients” may well have biological effects
when injected into the body in small amounts: fetal bovine, calf, egg or
human albumin; formaldehyde; insect cells; mouse serum protein;
phosphates; polysorbates; potassium chloride; sucrose; MSG; and
Thimerosal.20
Unfortunately,
many of these ingredients are neither inactive nor inert and may have a
profound effect on the immune and neurological systems.
The Vaccine Process
As described in a presentation from the College of Physicians of Philadelphia, there are five stages to manufacturing a vaccine: (1) generate the antigen; (2) isolate the antigen; (3) purify; (4) strengthen; and (5) distribute.21The first stage involves either growth and harvesting of the microbe (inactivated later) or using DNA technology to create a protein derived from the microbe. Viruses are grown in cell cultures (chicken embryos for example), while bacteria are reproduced in “bioreactors,” using a growth medium. The second stage is to free up the virus or bacteria and separate it as much as possible from other substances found in either the cell line or the growth medium.
Next, the antigen is purified. At that point, any other ingredients to be included in the final vaccine are added to the antigen, including the adjuvants, stabilizers, and preservatives. Before a vaccine is considered ready for distribution, it is mixed in a large container to ensure uniformity, and then packaged into sterile single- or multiple-dose vials.
Understanding Vaccine Assumptions
The concept of vaccination as the cornerstone of disease prevention has been so thoroughly accepted by so many for so long that in most circles it is considered unacceptable to even suggest that there is much more to learn and there are two legitimate sides to the debate about the value versus the dangers of vaccination. The best hope we have of keeping the conversation going and counteracting the derision and dismissal that faces anyone with questions about vaccination is to arm ourselves with as much credible information as we can find.Only when we truly understand assumptions and myths about vaccination can we gain perspective and offer valid arguments based on solid science.
References:
No comments:
Post a Comment