Ramblings On Vaccination

Vaccination has been hailed as one of the most important milestones in modern medicine.  Despite packets of resistance by some sectors who raised concerns on the safety and efficacy of vaccines as I have shown in my earlier post, vaccination has succeeded in eliminating some of the diseases that have plagued humanity throughout human history.  The eradication of smallpox, which was last seen in a natural case in 1977, is considered the most spectacular success of vaccination.  The next target would be polio but some isolated human populations are still beyond reach thwarting the full eradication of the disease.  But even as some individuals are not being vaccinated, either due to their remoteness or due to their outright refusal to be vaccinated, they are still indirectly protected by vaccination through “herd immunity.”  Since the majority of the population are no longer carriers or reservoirs of the disease, even individuals who are not vaccinated are indirectly conferred protection due to the absence of or of limited contagion.

Now, many may have asked if vaccination is so effective why have science not come up with a working vaccine against modern-day diseases like HIV-AIDS, influenza or Dengue fever.  The answer to that question has bearing not only on the causative disease organism but also on the workings of the immune system.

About fifty years ago, scientists reported evidence of some curious behavior by the immune system in humans and animals:  If a host was exposed to a pathogenic virus and later encountered a variant strain of the same virus, the immune system responded to the second attack largely with the same weapons it used against the first one.

Like an army still fighting by the tactics of the last war, the host immune system mostly produced antibodies matched to the first virus instead of the second, resulting in a less effective defense and whenever that same virus with a new strain attacks the host, the body will still use these weapons as the default response.  With reference to theology, this phenomenon was labeled "original antigenic sin."

We will explore this peculiar characteristic of the immune response in greater detail in our succeeding posts.   

Through almond eyes:

Th3re 1s n0 h0pe 0f d01ng p3rfect r3search.

J. M. E. Almendras

Yes, th3re 1s n0 h0pe 0f d0ing p3rfect r3search (Griffiths, 1998) because science or the whole body of human knowledge is a dynamic system that is constantly growing.  This growth may have spurts in most places, and stunting errors in some.  But science and the scientific method have built in mechanisms for adjusting, correcting and avoiding these growth errors.  The design of an experimental study is specifically tailored to achieve its objectives that minimize bias through randomization, maximize accuracy through replication of test subjects then analysing data through rigorous statistical procedures. But despite all these a perfect outcome can hardly be achieved.  In the social sciences where qualitative rather than quantitative data are generated, the test subjects are usually people who are often less than candid due to issues of privacy and confidentiality.  In this type of research, the presence of the researcher can have an effect on the subjects interviewed or observed, and add to that is the fact that both researcher and subjects have their own biases. On the other hand, biological science, despite its use of objective quantitative approaches, is no stranger to controversies either.  In recent years, some scientists from respected institutions have been accused of widespread misconduct, while some landmark research papers have been retracted after being pointed out by critics to have technical errors or sloppy methodologies.

The growth of scientific knowledge is a democratic process and thus science cannot speak with one voice.  For example, in the past decades numerous studies have been conducted that established and verified the beneficial effects of vitamins and vitamin-mineral supplements.  But when scientific research is funded, conducted then published by corporations which will profit from positive results, it is safe to assume that studies that have shown negative findings will not be published thereby making subsequent reviews and analyses of published data to be skewed.  So we are grateful to independently funded research in giving us more truthful data albeit negative.  Recently, some research papers have shown the ill effects of vitamin supplementations at dosages or packaging that are readily available in groceries, health food stores or from the internet.  Vitamin E had long been regarded as a wonder supplement that could ward off all sorts of diseases including cancer.  But a recently concluded study (Klein et al., 2011) have shown that dietary supplementation with vitamin E significantly increased the risk of prostate cancer among healthy men.  An earlier review paper (Tanvetyanon and Bepler, 2008) that analysed published data on beta-carotene, a form of vitamin A that is included in most multivitamin formulation, concluded that high dose beta-carotene supplementation appears to increase the risk of lung cancer particularly among current smokers.  Another study, that came out recently, disputed further the health benefits of vitamins and mineral supplements (Mursu et al., 2011).  The said study followed 38,000 older women over a 20-year period and found that supplementation with multivitamins, copper and iron were statistically associated with an increased risk of death.  This association is strongest with the intake of supplemental iron and surprisingly, in contrast to the findings of previous studies, calcium is associated with decreased risk of early death.

As science grows, the public distrust in science grows with it simply because scientific research is not perfect.  We have seen that certain sectors of society have shifted into denial mode. There is a growing culture of denialism, from climate change denialism to HIV-AIDS and vaccination denialisms.  Since climate change is in the realm of the physical sciences, we shall limit our discussions here on the latter two.  Denialisms in biology are often instigated by respected scientists holding positions in respected institutions.  The case of AIDS denialism simply ignores the huge and growing body of evidence that conclusively show that HIV (human immunodeficiency virus) causes AIDS.  But the father of all HIV-AIDS denialist, Professor. Peter Duesberg of the University of California, Berkley, contends that HIV is a harmless passenger virus and the antiretroviral treatment (ART) for AIDS is toxic and may even be the cause of AIDS itself (Duesberg, 1987; Duesberg et al., 2011).  Sadly, these assertions have resulted in thousands of deaths and new AIDS infections in Africa and elsewhere in the world as HIV-positive individuals stopped taking their medications.  These are mortalities and transmissions could have been avoided in the absence of denialism.

Vaccination has consistently been ranked as the most important medical discoveries in human history.  It is through vaccination that smallpox, one of the most devastating diseases known to humanity, was completely eradicated from the face of the earth. Vaccination’s next target for total eradication is polio.  However, the grand plans of medical authorities to eliminate fatal infectious diseases through vaccination have been derailed by the misinformation and distrust propagated by some vocal sectors of society and once again the spectre of denialism reared its monstrous head.  All these concerns regarding the safety of vaccines were triggered by a single scientific research paper published in the medical journal “The Lancet” in 1998 (Wakefield et al., 1998) which contends that autism spectrum disorders could apparently be caused by the mumps-measles-rubella (MMR) vaccine.  However, later investigations have exposed that the primary author of the article, Andrew Wakefield, had numerous undeclared conflicts of interests, rigged research results and had violated medical ethical codes.  Since its publication in 1998, other scientists have failed to replicate the controversial findings that Wakefield and his colleagues have claimed.  Subsequently, in 2010, the Lancet completely retracted the 1998 paper from the scientific literature. 

A growing body of knowledge, no matter how old, experiences growing pains.  As we have shown here research is not perfect, thus we can expect that all these errors, negative growth, controversies, retractions, vested interests, conflict of interests and denialisms will continue as scientific knowledge continues to grow.  We can also expect more noise, more distractions, more urban legends and more conspiracy theories as a result of the democratization of the ever growing body of scientific information.

References

Duesberg, P. H. (1987).  Retroviruses as carcinogens and pathogens:  Expectations and reality.  Cancer Res. 47: 1199-1220.

Duesberg, P. H., Mandrioli, D., McCormack, A., Nicholson, J. M., Rasnick, D., Fiala, C., Koehnlein, C., Bauer, H. H., and Ruggiero, M. (2011).  AIDS since 1984: No evidence for a new, viral epidemic – not even in Africa.  Ital. J. Anat. Embryol. 116: 73-92.

Griffiths, M. (1998) Educational Research for Social Justice: Getting off the Fence.  Buckingham:  Open University Press.

Klein E. A., Thompson, I. M. Jr., Tangen, C. M., Crowley,  J. J., Lucia, M. S., Goodman, P. J., Minasian, L. M., Ford, L. G.,  Parnes, H. L.,   Gaziano, J. M.,  Karp, D. D., Lieber, M. M., Walther, P. J., Klotz, L.,   Parsons, J. K.,  Chin, J. L., Darke, A. K., Lippman, S. M., Goodman, G. E., Meyskens, F. L. Jr, and Baker, L. H. (2011).  Vitamin E and the risk of prostate cancer.  The selenium and vitamin E cancer prevention trial.  JAMA. 2011;306(14):1549-1556.

Mursu, J., Robien, K., and Harnack, L. J., Park, K. and Jacobs, D. R. Jr, (2011).  Dietary supplements and mortality rate in older women.  The Iowa Women's Health Study.  Arch Intern Med. 171(18):1625-1633

Tanvetyanon, T., and Bepler, G. (2011).  Beta-carotene in multivitamins and the possible risk of lung cancer among smokers versus former smokers:  a meta-analysis and evaluation of national brands. Cancer. 113(1):150-7.

Wakefield, A. J., Murch, S. H., Anthony, A., Linnell, J., Casson, D. M., Malik, M., Berelowitz, M., Dhillon, A. P., Thomson, M. A., Harvey, P., Valentine, A., Davies, S. E., Walker-Smith, J. A.  (1998).  Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children.  The Lancet 351 (No 9103): 637-641. (RETRACTED)