July 09, 2008
Lost amidst all the furor over the role of vaccines in autism has been the role that vaccine administration plays in causing other chronic childhood diseases like asthma and juvenile diabetes. But the evidence that vaccine administration, especially early administration of DPT vaccine, increases the risk of developing asthma (for the purposes of simplicity, let’s shorten that phrase to causes asthma for what follows) is compelling. If you look at the totality of the published evidence the picture is admittedly somewhat mixed, but for anyone with an open mind and a critical eye, the argument for a strong role for vaccines as a cause of asthma is persuasive.
And for any parent trying to figure out whether or not to comply with the aggressive and crowded vaccine schedules, the message from this evidence is simple. Don’t comply. Go slower than they want you to. Take responsibility for your own child’s health. Because recent research shows not simply that vaccines cause asthma, but that the sooner you give your child some vaccines the higher the odds that your child will develop asthma. These are obviously critical and controversial points, so let’s take a some time to review some of this research.
In a study published earlier this year, a group of Canadian researchers from the University of Manitoba examined the connection between asthma and vaccines in one of the largest studies ever to address the question. What they found was clear and striking. The earlier children received their DPT shots, the higher their odds of developing asthma by their seventh year of age. To be more precise, among children born in Manitoba in 1995 who received their first shot on time (on or before two months of age), nearly 14% subsequently developed asthma. By comparison, among children who received their first shot late (six months or later), less than 6% developed asthma. That’s a “crude odds ratio” (before statistical adjustments for “confounders” that might bias the result) of 2.6, meaning that a child vaccinated on schedule is over two and half times more likely to develop asthma than a child vaccinated late.
I’ve displayed these results from Manitoba visually in the chart below. There are a number of nuances in this display that I want to point out, but the basic message is simple. The sooner families in Manitoba lined up to give their children their first DPT shot (age at administration of the first DPT vaccine is on the horizontal axis), the more they raised their child’s odds of developing asthma (the risk of developing asthma by age 7 is on the vertical axis), odds that by my estimate may rise as much as 3-4 times higher once the full range of vaccination timing is considered.
In other words, earlier vaccination causes asthma.
Now to the nuances (warning for the English majors, if you want to skim over the quantitative discussion, skip down three paragraphs). You can see the main reported findings in the Canadian study by following the trends shown in the black lines and scales. These black lines show the risk (as measured by the “crude odds ratio”) of earlier vaccine administration using the most delayed group as the reference point [Note: for display purposes, I’ve switched the reference group that the Canadian researchers used and assigned an odds ratio of 1.0 to the most delayed group rather than the on-schedule group. The underlying numbers are the same]. The difference in odds between the reference group and the on schedule group was 2.6 times. When the researchers made a variety of statistical adjustment, their reported “adjusted odds ratio” was a bit smaller (it fell to about 2.0 times) but in both their crude and adjusted numbers, the difference between the early and late groups was statistically significant.
One thing I found quite interesting, when reading the fine print in the paper was a more targeted analysis that the authors did for the on-schedule group. The authors broke this group up into three subsets for a special analysis, which I’ve shown here on the same display but, to set off if off from the main analysis, using red lines and scales. This special analysis compared the “adjusted odds ratio” for the ahead-of-schedule group and estimated that the asthma risk for this group was 60% higher than the right-on-schedule group (the results weren’t statistically significant due to the small size of the ahead-of-schedule sample). The authors didn’t report the crude odds ratio, but if one makes a few assumptions, one can align this adjusted odds ratio display (the red lines and scales) with the parallel display showing the crude odds ratio (the black lines and scales). Looking at the data this way suggests that the odds of getting asthma rise even higher when a child receives the DPT vaccine earlier: this earliest group appears to have had nearly 4 times higher odds of developing asthma than the group vaccinated the latest.
[Full disclosure note: I had a pleasant email exchange with the corresponding author, Anita Kozyrskyj. She declined to provide the data that would permit a more direct calculation of the crude odds ratio for the ahead-of-schedule sub-groups and, because of the small numbers involved, counseled against viewing the red line results as a continuation of the black line data. I think she’s being too careful, but because of her counsel I have taken pains here to dissociate the two lines and mark them each with their own separate scale. The choice to align the two scales in a way that suggests a more extended trend is my own.]
I realize I may have lost some of you along the way. But I think two things are critical when reviewing studies like these: 1) respecting the evidence and the underlying data, not forcing it to be something it’s not, which is why I’ve complicated the matter with the red and the black lines; and 2) cutting through the fog of political correctness and fear that surrounds the management of vaccine safety, which is why I’ve displayed the two trends together. The simplest interpretation of this data set, however, is clear and bears repeating: earlier DPT vaccination causes asthma. And the current vaccine schedule, which promotes more and more vaccines earlier and earlier, is demonstrably unsafe.
It’s also important to recognize that this Canadian study isn’t covering virgin territory. Although it’s the first to examine the specific question of vaccination timing so carefully (as opposed to a simpler vax/unvax study design), it’s not the first to address the question of vaccination and asthma. Far from it. Indeed there’s a long parade of studies, covering many different countries, many different vaccines and using many different study designs. At the highest level, these studies come in two flavors. The first are the less formal vax/unvax surveys, the kind conducted by outsiders to the medical establishment who are worried that the insiders are out of control and not paying attention to the epidemic of chronic disease. Without large resources, prestigious institutions and large research budgets behind them, these efforts pursue the simplest path with the least complexity: they go out and find two populations—one vaccinated and one not—and compare their health outcomes. Time after time, studies like these, whether from our own sponsor Generation Rescue, the Dutch Association for Conscientious Vaccination, or the Immunization Awareness Society in New Zealand, yield similar findings when it comes to asthma. Vaccinated children always have sharply higher risk of developing asthma than unvaccinated children, anywhere from two to six times higher.
There is, of course, another class of study, the kind that makes its way into an indexed medical journal. And although the evidence from this body of work is less consistent than the grass-roots efforts, the weight of evidence among this group of studies is remarkably similar as well. I’ve read through a large number of them myself (I have provided a list of the most relevant published studies below) and I will summarize them here only briefly. Suffice it to say, there are a number of recognizable patterns in these studies, most of which (like the Manitoba study) focus on the DPT shot. A few (most notably two German studies) actually have shown a protective effect of vaccination.. But the majority of them report some kind of elevated asthma risk with vaccination: anywhere from 20% higher to 14 times higher. These studies often draw on smaller samples than the Manitoba study(following hundreds rather than thousands of infants), which is why the Manitoba analysis, with a study population of over 11,000 was so informative..
In fact, every study with a sample population larger than 10,000 shows a significant link between vaccines and asthma: every study, that is, except one performed by the CDC under the guise of the Vaccine Safety Datalink (VSD) program. The CDC has conducted a number of studies on vaccines and asthma. In every case, after deploying elaborate statistical gyrations not at all unlike the infamous Verstraeten study, the authors conclude that vaccines have nothing to do with asthma. The CDC never met a vaccine that made a child sick, so not surprisingly, these studies unfailingly deliver the party line: “do what we tell you to do”.
It’s important to recognize, however, that the VSD findings go against the weight of evidence. When reading the bulk of the literature, after you cut through the fog of public health propaganda (no one ever says “vaccines cause asthma” in a mainstream medical journal) one cannot help but be persuaded by the weight of evidence. Vaccines cause asthma. So, just like the autism epidemic, the expansion of the vaccine program is likely to have sparked another epidemic of childhood disease. This one, unlike autism, can cause fatal medical complications.
So as evidence mounts for the rising health consequences of the massive human experiment of intensive vaccination launched on this latest generation of children, it has become clear that the debate as it has evolved has become less about the evidence than about belief systems. In a very real way, the proponents of the intensive vaccination experiment want to avoid the usual constraints of health monitoring and safety management because they believe in the project of intensive vaccination as a kind of crusade.
We need to move beyond the religious wars and make it safe again to discuss evidence about vaccine safety, frankly and openly. And a study like the Manitoba effort, if halting in its conclusions, is unambiguous in its result. Vaccines cause asthma. It’s not a complicated problem, folks, it’s what the data are telling us
Mark Blaxill is Editor-at-Large for Age of Autism
References (studies with elevated odds ratios for asthma risk due to vaccine exposure are noted with an asterisk)
*McDonald KL, Huq SI, Lix LM, Becker AB, Kozyrskyj AL. Delay in diphtheria, pertussis, tetanus vaccination is associated with a reduced risk of childhood asthma. J Allergy Clin Immunol. 2008;121(3):626-31.
*Kemp T, Pearce N, Fitzharris P, Crane J, Fergusson D, St George I, Wickens K, Beasley R. Is infant immunization a risk factor for childhood asthma or allergy? Epidemiology. 1997;8(6):678-80.
*Wickens K, Crane J, Kemp T, Lewis S, D’Souza W, Sawyer G, Stone L, Tohill S, Kennedy J, Slater T, Rains N, Pearce N. A case-control study of risk factors for asthma in New Zealand children. Aust N Z J Public Health. 2001;25(1):44-9.
*Odent MR, Culpin EE, Kimmel T. Pertussis vaccination and asthma: is there a link? JAMA. 1994;272(8):592-3.
*Farooqi IS, Hopkin JM. Early childhood infection and atopic disorder. Thorax. 1998;53(11):927-32.
*McKeever TM, Lewis SA, Smith C, Hubbard R. Vaccination and allergic disease: a birth cohort study. Am J Public Health. 2004;94(6):985-9
Henderson J, North K, Griffiths M, Harvey I, Golding J. Pertussis vaccination and wheezing illnesses in young children: prospective cohort study. The Longitudinal Study of Pregnancy and Childhood Team. BMJ. 1999;318(7192):1173-6.
*Maitra A, Sherriff A, Griffiths M, Henderson J; Avon Longitudinal Study of Parents and Children Study Team. Pertussis vaccination in infancy and asthma or allergy in later childhood: birth cohort study. BMJ. 2004;328(7445):925-6.
Nilsson L, Kjellman NI, Björkstén B. A randomized controlled trial of the effect of pertussis vaccines on atopic d isease.Arch Pediatr Adolesc Med. 1998;152(8):734-8.
Nilsson L, Kjellman NI, Bjorksten B. Allergic disease at the age of 7 years after pertussis vaccination in infancy:results from the follow-up of a randomized controlled trial of 3 vaccines. Arch Pediatr Adolesc Med. 2003;157(12):1184-9.
Bernsen RM, de Jongste JC, van der Wouden JC. Lower risk of atopic disorders in whole cell pertussis-vaccinated children. Eur Respir J. 2003;22(6):962-4.
*Bernsen RM, de Jongste JC, Koes BW, Aardoom HA, van der Wouden JC. Diphtheria tetanus pertussis poliomyelitis vaccination and reported atopic disorders in 8-12-year-old children. Vaccine. 2006 15;24(12):2035-42.
*Bernsen RM, Nagelkerke NJ, Thijs C, van der Wouden JC. Reported pertussis infection and risk of atopy in 8- to 12-yr-old vaccinated and non-vaccinated children. Pediatr Allergy Immunol. 2008;19(1):46-52.
Grüber C, Illi S, Lau S, Nickel R, Forster J, Kamin W, Bauer CP, Wahn V, Wahn U; MAS-90 Study Group. Transient suppression of atopy in early childhood is associated with high vaccination coverage. Pediatrics. 2003;111(3):e282-8.
Möhrenschlager M, Haberl VM, Krämer U, Behrendt H, Ring J. Early BCG and pertussis vaccination and atopic diseases in 5- to 7-year-old preschool children from Augsburg, Germany: results from the MIRIAM study. Pediatr Allergy Immunol. 2007;18(1):5-9.
*Hurwitz EL, Morgenstern H. Effects of diphtheria-tetanus-pertussis or tetanus vaccination on allergies and allergy-related respiratory symptoms among children and adolescents in the United States. J Manipulative Physiol Ther. 2000;23(2):81-90.
*DeStefano F, Gu D, Kramarz P, Truman BI, Iademarco MF, Mullooly JP, Jackson LA, Davis RL, Black SB, Shinefield HR, Marcy SM, Ward JI, Chen RT; Vaccine Safety Datalink Research Group. Childhood vaccinations and risk of asthma. Pediatr Infect Dis J. 2002;21(6):498-504.
Maher JE, Mullooly JP, Drew L, DeStefano F. Infant vaccinations and childhood asthma among full-term infants. Pharmacoepidemiol Drug Saf. 2004;13(1):1-9.
Mullooly JP, Pearson J, Drew L, Schuler R, Maher J, Gargiullo P, DeStefano F, Chen R; Vaccine Safety Datalink Working Group. Wheezing lower respiratory disease and vaccination of full-term infants. Pharmacoepidemiol Drug Saf. 2002 ;11(1):21-30.