Vaccination Issues: A Chiropractor's Perspective

The recent article by Colley et al.¹ has provided the impetus for the writing of this article on the topic of vaccines and vaccination. The authors raised some very interesting issues in response to a previous article I had written on vaccination.² In my first article, I examined relevant topics concerning the conventional practice of "mandatory" and/or universal vaccination. As I stated and as substantiated by the response of Colley et al., the subject of vaccination is controversial. It is my hope that through this dialog and forum we are all better informed on the subject, regardless of one's perspective on the issue. As such, I would like to further clarify the issues raised and address comments made by Drs. Colley, Morgan and Haas.

Colley et al. commented that my statement on the efficacy of vaccines is no more than an opinion because I have neglected to present the data in an epidemiological context. To illustrate their point, they discussed the importance of epidemiological assessment, as it applied to risks, by using cervical manipulation and cerebrovascular accidents. I could not agree more with their comment that condemnation of adjustments to the cervical spine without risk-factor analysis is meaningless. Based on works by Klougard et al.³ and Leboeuf-Yde et al.,⁴ according to Colley et al., "Some cervical manipulations are not associated with any risk. No reasonable person would dismiss all cervical procedures on the basis of such insignificant risks."

The subject of cervical manipulation is also fraught with controversy. A study by Dvorak and Orelli,⁵ found that in one out of 40,000 cases, slight neurological complications were observed and an average of one important complication was observed in an estimated total of 400,000 manipulative procedures. According to Haynes,⁶ the incidence is less than five per 100,000 patients who receive neck manipulation. Michaeli⁷ found one reported case of VBA out of an estimated 228,050 manipulations. According to Assendelft,⁸ "it is impossible to derive exact figures regarding the risks for patients from the published literature." And that, "It is very likely that the number of complications are actually higher than the cumulative number of cases reported in the literature." In addressing the correctness of risk factors as it pertains to spinal manipulation, Powel et al.⁹ found the risk of spinal manipulation to the cervical spine to be "unacceptably high." However, according to Colley et al., "no reasonable person" would dismiss all cervical procedures on the basis of such insignificant risks."

What Drs. Colley, Morgan and Haad fail to realize and failed to point out is that while the risk of injury or stroke from cervical spinal manipulation is low, this risk is unacceptable when cervical manipulation is routinely used as a preventative measure on "asymptomatic" patients or for which manipulation is contraindicated.^10,11In addition, what constitutes "asymptomatic" may also be controversial. For me, whether to adjust or not adjust an individual is based on subluxation findings^12,13and the appropriate indications and contraindications.

According to Colley et al., "The risk of morbidity and mortality from the disease should be weighed against the risk of injury from the vaccine." As an example, they cite rabies and asked if anyone who had been bitten by a rabid wild animal would question the transient side-effects of the vaccine. Overt rabies in humans may essentially be considered 100 percent fatal without vaccine intervention. However, the issue of risk from the morbidity and mortality of a disease versus risk of injury from vaccination is not as simple as they have commented and not so clear-cut. Using their example of the rabies vaccine, let us consider the issue from the perspective of implementation versus application of vaccines. With rabies in humans, the vaccine is applied to infected individuals (postexposure prophylaxis) or to individuals at special risk (i.e., veterinarians, animal workers, etc.) and there is a potential exposure to rabies (pre-exposure prophylaxis) in these individuals.¹⁴

Given the above scenario, would Colley et al. advocate the implementation of mass vaccination of the rabies vaccine to all individuals regardless of exposure or possible risk of exposure? More importantly, would parents advocate or agree to vaccinate their young with the rabies vaccine regardless of exposure or possible risk of exposure? I would agree that a rabies-infected individual would not question the side effects of the vaccine for the obvious reason that infection is lethal without intervention. However, what Colley et al. failed to realize and failed to point out is that this type of vaccination is a therapeutic intervention. Mass vaccination as advocated for the purpose of prevention of disease is a prophylactic intervention.

With respect to adverse reactions, certainly there may have been adverse reactions once thought to be possibly associated with vaccines that are no longer associated to the vaccines. Colley et al. provided four examples cited from the scientific literature to make their point. Errors in associating so-called adverse events with particular vaccines does not refute the existence of adverse reactions to vaccines in general. And using their argument of improved studies and improved technology to detect lack of association of adverse reactions with particular vaccines, one may also reason that improved technology may better detect associations of adverse reactions with particular vaccines. Adverse reactions associated with vaccines are documented in the literature.^15-17

Fine and Chen¹⁸ reviewed the literature on studies of severe adverse events after the administration of pertussis antigen-containing vaccines, with particular attention to measures taken by different investigators. Most published studies have reported a deficit of SIDs in those immunized. According to Fine and Chen, there may be biases in such studies that underestimate the risks. They concluded: "The fact that such biases do exist makes it difficult to demonstrate convincingly that a vaccine is not responsible for rare, severe, adverse reactions."

In a recent article by Salisbury in the prestigious journal Lancet,¹⁹ the association between the polio vaccine and Guillain-Barre syndrome was discussed. Salisbury comments on the evidence and possible reasons favoring or refuting an association between OPV and Guillan-Barre syndrome. For example, while the U.S. Institute of Medicine concluded that there is insufficient evidence for a causal relation between the DTP vaccine or the Pertussis component of the DTP vaccine and Guillan-Barre syndrome,²⁰ a later review favored a causal relation for the tetanus toxoid and Guillain-Barre syndrome.²¹ A causal relationship has also been found to be favored between Guillain-Barre syndrome and the use of oral polio virus vaccine in Finland.^22,23 Issues with respect to the reporting of adverse reactions and the long-term consequences of a vaccination program (i.e., autoimmunity, environmental evolutionary pressure, etc.) are subjects that further add to the controversy.

Colley et al. discussed the rare occurrence of anaphylaxis and the efficacy of the MMR vaccine according to "epidemiological evidence." According to Colley et al., "In regards to the efficacy of the measles vaccine, the WHO, the Pan American Health Organization, and the Centers for Disease Control project a plausible date of 2005 to 2010 for the global eradication of measles."

What happened to the year 2000? This was the projected date for measles eradication in 1988.²⁴Measles is the most transmissible disease known to man. In the 1980s, there was a dramatic increase in incidence of measles in the United States. For example, in 1989, among all reported cases of measles, 40 percent of the patients were vaccinated according to recommendations.18 In examining the apparent paradox of measles infection in immunized persons, Poland et al.,²⁵ noted that two types of outbreaks occur: 1) the unvaccinated (where the largest number of cases occurred). They note that in some major inner-cities, up to 60 percent of two year olds were not immunized against measles. 2) The second group occurred among school-aged and college-aged populations with high vaccination coverage rates (i.e., more than 98 percent of the students had previously been vaccinated). Poland et al. examined 18 published reports after 1977, for which they were able to calculate immunization rates in highly defined groups. In these groups, measles immunization rates ranged from 71-99.8%. Between 30% to 100% rates of immunization were documented, and yet outbreaks occurred. Modeling by Poland et al. found that as more and more of the population is vaccinated, the number of cases occurring in vaccinated individuals will exceed the number of cases occurring in the even smaller subgroups of the unimmunized. Poland et al. comment that the vaccine is highly effective yet vaccine failures (primary or secondary) will still occur.

Colley et al. discounted the role of sanitation in favor of vaccination, particularly in the global eradication of polio. For their perspective, they state that the last case of polio in South America was in 1991. They contend that the "only rational explanation" for the disappearance of polio in South America in 1991 was attributed to the establishment and maintenance of immunization, since at this same time a major cholera epidemic ensued. They dismissed the role of sanitation since polio and cholera "have identical epidemiology." Medical literature indeed state that the polio virus and cholera vibrio have an oral-fecal route of entry.^26,27 However, serious epidemiological consideration should account for unique characteristics of the two organisms. For example, an awareness of something as simple as the reservoir of the two organisms have important ramifications in the eradication of the two organisms. The only known reservoir for the polio virus (other than laboratory stock) is also its host -- man.²⁸

Cholera has historically been associated with epidemics spread by widespread contamination of aquatic environments.²⁹ The ability of vibrio cholerae to survive in sea and fresh water make it much more difficult to eradicate than polio. Cholera is a human disease in which its transmission can be controlled by universal availability of appropriate sewage disposal and clean water.³⁰As a matter of historical note, the first (live, parenteral) cholera vaccine that entered into clinical trials was in 1885.³¹ To this day, an effective vaccine has not yet been developed against cholera. Vibrio cholera, the causative microbe of cholera requires two highly regulated factors for full virulence: the cholera toxin, and the toxin-coregulated pili, a surface organelle required for intestinal colonization. The vaccine against cholera is against the toxin, not the organism itself. To create the cholera toxin or toxoid, the toxin is inactivated by passing through formaldehyde.³² With this process, the toxoid loses some of the epitopes for binding to antibodies, making a less than optimal or effective vaccine. In addition, the immune response with the cholera toxoid is not a systemic response. There is no immune response per se by the host since the vaccine does not enter the blood stream. There is no Ig G response. More than likely an Ig A response may be produced since secretory Ig A is present in the gut where the bacteria releases the toxin to effect the symptoms of cholera.³³

In the area of vaccine development against cholera with the use of attenuated cholera vibrio, there are problems. It has been found that bacterial virulence factors are encoded by accessory genetic elements such as bacteriophages (viruses attacking bacteria), plasmids, chromosomal islands and transposons. These accessory genetic elements are thought to infect bacteria, thereby conferring increased evolutionary fitness to their pathogenic host and to their own genetic elements. The genes for the cholera toxin have been found to reside on the bacteriophage CTX. Waldor and Mekalonos³⁴ demonstrated the possibility that classical strains of vibrio cholerae may be less suitable as live attenuated cholera vaccines, given their potential for re-acquisition of the genetic element for cholera toxin by means of the CTX transduction. In simpler terms, attenuated vibrio cholera as vaccines can be infected by bacteriophage (bacterial viruses) conferring upon it pathogenecity, making the vaccine essentially useless and the organism harmful.

Colley et al. cited the high prevalence of infectious diseases in the Russian Federation. They account for this observation due to poor vaccination coverage. Certainly there have been dramatic outbreaks of infectious diseases in the Russian Federation but to solely account for this due to poor vaccination coverage is overtly simplistic and somewhat naive. Epidemiological consideration to the rise of infectious diseases must take into account, what are called potentiating factors or factors called determinants of health. These are factors such as the economic and social instability of a country, the rise in alcohol and tobacco consumption by the populace, poor nutrition, stress and depression and a severely impaired health care system. Such factors played a major role in the overall decline of the health of the Russian populace and set the stage for the outbreak of infectious disease.³⁵

Colley et al. cited examples of rapid changes in disease incidence in countries that have let their immunization levels drop. They discount the BCG vaccination termination study by Trnka et al.,^36-38 because of the chronic and slow-developing nature of tuberculosis. For clarification, the study by Trnka et al. was performed in a six-year period beginning in 1986. The slow and chronic characteristic of the disease may make it difficult to detect infected persons until they have experienced months or years of active infection. However, the use of the tuberculin skin test may be relied upon to detect an infected person, regardless of whether the disease is quiescent or active. The test was performed in the BCG vaccine termination study.

Colley et al. cited pertussis incidence to demonstrate the changes in disease incidence when the organism is more dynamic and not so slow and chronic. Their assertion is that with decreased immunization levels, incidence of the disease increases. I have shown that with particular types of infectious diseases, a paradox may occur whereby increased incidence of the disease occurs with immunization, as in the measles vaccine. It is interesting that according to Colley et al., Great Britain, Sweden and Japan had decrease their use of the pertussis vaccine because of fears about its safety. So chiropractors are not the only ones who have fears regarding the safety of vaccines. Perhaps Colley et al. can elaborate and clarify why this occurred in three industrialized countries as a result of fears of vaccine safety. Again, I assert that vaccine safety and adverse reactions are legitimate concerns on the issue of vaccination.

Colley et al. have requested I clarify the issue of immunization with respect to my comments: "inner city children living in poverty with poor hygiene and poor nutrition;" that "there is ample evidence that vaccination needs to be directed to low-income minority pre-school children." They have made comments that I was implying in my article that chiropractors apply a "double standard" in advising patients about immunization; that this same rationalization was used to justify an infamous syphilis study in rural Alabama. For further clarity in this discussion, let me reprint the comments I had made to demonstrate the context in which I had made those comments for the benefit of the readership.

Role of the Chiropractor

The crux of the question for our profession is fundamentally whether chiropractors should advocate to enhance the host response to illness through a holistic approach (e.g., chiropractic adjustments, nutrition, hygiene, etc.)? Or are these approaches to health care relegated to a secondary or a nonexistent role? On the other hand, should a chiropractor tell the parents of an inner-city child living in poverty with poor hygiene and poor nutrition that they should not be immunized? I certainly do not advocate such a position, that the types of factors that could influence the child's health are not being addressed. Conversely, to advocate mass vaccination of the populations without addressing the socioeconomic, hygienic and nutritional factors in an individual's health care program is an equally irresponsible position. There is ample evidence that vaccination needs to be directed to low income, minority preschool children.

It is common knowledge in public health education and research that many socioeconomic risk factors and personal barriers to the use of preventative services exist. These are supported by many studies in the scientific literature and have been identified by the Institute of Medicine.³⁹ As published in the prestigious journal JAMA,⁴⁰ disparities in vaccine coverage have been documented among different racial/ethnic groups. In the article cited, the Centers for Disease Control asserts that "efforts to increase vaccination coverage must be intensified to achieve coverage goals for all children, particularly children of racial/ethnic minority groups living in poverty." As such, the "CDC will continue using the National Immunization Survey to monitor progress towards meeting national health objectives for the year 2000 by race/ethnicity and by other factors associated with undervaccination."

The study by Wood et al.⁴¹ as referenced in my original article examined the factors associated with undervaccination at three months and 24 months among low-income, inner-city Latino and African-American preschool children. Under their summary and discussion, only 42 percent of the Latino children and 26 percent of the African-American children were UTD (up-to-date) at age two in their vaccination coverage, well below the 90 percent national target for pre-school children.

Unless the low immunization rates in inner-city areas are raised, these areas will continue to be at risk for epidemics of measles and other vaccine-preventable diseases. Wood et al. concluded that the "immunization rates among inner-city, Latino and African-American 2-year-old children to be low in 1992," the year the study took place. As in my original article, this reference asserts my original comment. With all respect to Colley et al., my references do support my assertions and I encourage them to read the article again.

In another study by Wood et al.⁴² published in JAMA (1998), the effectiveness of case management in raising immunization levels among infants of inner-city African-American families was examined. According to Wood et al., children who are poor, live in urban areas, or are members of minority groups are less likely to be up-to-date in their immunizations than the general population, and their immunization rates may be much lower than they do in other parts of the United States. This assertion is also supported elsewhere by others.^43-44As such, Wood et al. commented: "To be effective, case management should be targeted to high risk groups that will benefit from the intervention, potentially through the use of immunization registries in low-income and rural areas."

In a study by Kenyon et al.,⁴⁵ the vaccination coverage among children 19-35 months from public housing developments (where a free vaccine outreach program was in place) were compared with those of children residing elsewhere. They found that the children in the public housing developments were "amidst a population characterized by low income, minority racial and ethnic groups, large family size, and young maternal age." They concluded from their study that "African-American children throughout Chicago, particularly in public housing, remain at increased risk for vaccine preventable diseases and should be targeted for further vaccination services."

In light of the above discussion, I am somewhat perplexed that Drs. Colley, Morgan and Haas should question the motives behind my comments regarding vaccination of low income, minority preschool children living in poverty and in inner cities. The scientific and medical literature support my statement. Organizations such as the American Public Health Association and the Centers for Disease Control have implemented a vaccination program as per my comments. I strongly recommend that at least one of the authors (Drs. Colley, Morgan and Haas) perform a MEDLINE search for vaccination with regard to ethnicity, race, low income and poverty. Perhaps from a more informed or proper perspective, they would realize that socioeconomic factors are determinants of access to or lack of access to health care and, in particular, vaccination. Their proper perspective of vaccinating minority children living in inner cities should be more from an appreciation for the determinants of health rather that making comments that smack of racism. I made my comments not to imply to chiropractors that they should apply a "double standard" when advising patients about vaccination, but rather in the proper context/perspective and realization that these socioeconomic factors provide unique circumstances for the individual patient or patients involved, particularly with regards to their health. Doctors of chiropractic and other health care providers should always be cognizant of this. It is well recognized that socioeconomic status contributes to or is a determinant of premature and preventable morbidity and mortality.^46-48

If the reference by Drs. Colley, Morgan and Haas of an infamous syphilis study in Alabama refers to the Tuskegee syphilis study, then their comments in reference to my article is definitely out of context and inappropriate. The Tuskegee syphilis study was a disturbing account of how, beginning in 1932, poor African-American men in Tuskegee, Alabama who suffered from syphilis were denied access to care (i.e., penicillin) by the public health service. The truth came to light by the news mediain 1972. It was a story that drew widespread public criticism and condemnation. Was racism an issue in the Tuskegee incident? Certainly. Are the motivations for targeting minority preschool children living in inner cities for vaccination even remotely related to the justification of the Tuskegee syphilis study? Certainly not. As I have shown, "There is ample evidence that vaccination needs to be directed to low income, minority preschool children." The Tuskegee study has and will continue to be an interest to health care providers, researchers, historians, bioethicists and those concerned with the experiences of African-Americans in the 20th century.

What have we learned from the Tuskegee incident? A lesson learned that is more applicable and appropriate for these discussions on vaccination is the issue of informed consent and patients' right to self-determination. Future articles will address these issues. Since the Tuskegee syphilis study had such a great impact on the ethical consideration with respect to research and treatment of individuals (particularly minorities), perhaps Drs. Colley, Morgan and Haas can clarify for us how targeting minority children living in poverty and inner-cities has the same justification for performing the Tuskegee syphilis study. This would make interesting reading on the subject of ethics and issues in public health, since the present vaccination program they support target minority children living in inner-cities for vaccination.

Colley et al. commented that some in the chiropractic profession are still unwilling to accept immunization despite the overwhelming scientific evidence. They cite a commentary paper on pertussis immunization update by one of the co-authors (L Morgan) to support this statement.⁴⁹ Colley et al. commented that, "a small and outspoken minority contributes to an unwarranted but widespread impression that chiropractors have limited education, training or perspective in basic science and public health." They cite a 1994 paper by two of the co-authors ⁵⁰ in support of this statement. According to this paper, in the abstract conclusion, the authors comment, "There is a significant minority of American chiropractors who harbor anti-immunization sentiments despite the weight of scientific evidence. Greater efforts must be made by chiropractic educators, associations and licensing boards to ensure that clinicians base their attitudes on clinical and epidemiological research rather than emotion, rhetoric and dogma."

The paper by Colley and Haas surveyed one percent of the chiropractic population in 1994 (N=480) and they received a 37 percent response rate (i.e., 178 responded) from which to make their conclusions.

A survey by Szilagyi et al.⁵¹ of American pediatricians and family physicians in the United States was performed to asses their current practices and attitudes regarding vaccination. It is beyond the scope of this writing to describe the details of their study or findings. I will only point out the salient features appropriate for this discussion. Physicians were asked whether they would give simultaneous DPT, OPV, MMR and HiB vaccination to an 18-month child seen for well-child care. Only two-thirds of the pediatricians and family physicians would give all vaccines. The reasons for not giving simultaneous vaccinations are given in the table below:

• too painful to give three shots;
• parents would object;
• too costly;
• concern about side effects;
• concern about immune response;
• contraindications.

In another study performed by Zimmerman et al.,⁵² an attempt was made to determine the causes of low childhood vaccination rates based on physicians knowledge, attitudes and self-reported practices concerning childhood vaccinations. With respect to side effects, most physicians (88 percent of those surveyed) thought that there would be no side effects from the DPT shots when given during acute care visits. However, of this group, 55 percent indicated they were likely to vaccinate while 27 percent indicated they were unlikely. Twenty-five percent of the physicians surveyed thought that parents would object to vaccinations during an acute care visit. With respect to vaccine efficacy, 87 percent thought that the efficacy of the MMR vaccine would not decrease if given to a child who has a URI. According to Zimmerman et al., the reasons most commonly given for being less likely to vaccinate during an acute care visit were parental concerns, practice policies, focus on the acute care and limited time allotted for the visit. In the group of physicians who believed that vaccination during an acute care visit would have adverse reactions, lower vaccine efficacy, increased parental objections, concerns on the impact of practice operations; they were less likely to vaccinate. Physicians' reasons for not recommending simultaneous administration of vaccines were difficulty in determining which vaccines caused side effects, decreased vaccine efficacy and parental objection. In a more recent publication by Zimmmerman et al.,⁵³ they examined physicians' concerns about litigation and beliefs regarding vaccine safety. According to Zimmerman et al., many of the physicians surveyed who believed that adverse side effects from DPT are likely were highly concerned about litigation from injuries allegedly related to vaccination. Concerns about litigation made doctors less likely to encourage vaccination if the parents were argumentative about the adverse effects of vaccines.

Concerns regarding vaccine safety, efficacy and parental objections are not unique to chiropractors. Concerns of vaccine litigation and practice policy are issues that determine whether a medical physician administers the vaccine or not. I have discussed studies examining physician attitudes of implementating vaccinations. It has been shown that not all medical physicians adhere to the vaccination recommendations. Are we now to assume that these small and minority group of MDs contribute to a widespread impression that medical doctors have limited education, training or perspective in the basic sciences and public health? I don't think so. A reasonable person would realize that the issues are much more complex.

Parents may choose to vaccinate their children according to the universal immunization program as established; they may choose to vaccinate on a disease by disease basis; or they may choose to reject the vaccination program altogether.² Consideration of the factors involved in the decision making are many and diverse. They are predicated upon each person's beliefs, experiences, attitudes, values and educational experience. People make decisions based on their perception of the risks versus the benefits involved, the preference for one type of risk over another and the ability to control for variables such as personal lifestyle modification for health. For the individual with holistic approaches to health care, vaccination or the risks of vaccination may not be viewed as acceptable. For the individual with sociopolitical issues in mind, topics such as mandatory vaccination, informed consent and individual rights are very important in the decision process. In vaccination, as the target disease becomes more uncommon, the perceived risks attributed to the vaccine increases in importance. A consideration of this phenomenon is important. An awareness of this led to the termination of smallpox vaccination in many countries prior to its global eradication.¹⁸ A reconsideration of the polio vaccination policy is now underway based on similar concerns.

A meaningful dialog within our profession on the complex issue of vaccination begins with an appreciation for and knowledge of the issues raised for and against vaccination, rather than making unfounded comments based on rhetoric and dogma.¹

References

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