One of the chief claims of groups critical of vaccinations is that the SIDS rate dropped in Japan after the age for DPT vaccination was raised from 2 months to two years. Here are some references that bear on that issue.
Lon Morgan, a chiropractor, has a discussion of the claim with references. He traces the claim back to 1992:
"In 1992 Ms. Viera Scheibner published a book entitled "Vaccination 100 Years of Orthodox Research shows that Vaccines Represent a Medical Assault on the Immune System" wherein she repeatedly made the claim that after the Japanese changed their pertussis immunization policy in 1975 the phenomenon of SIDS (Sudden Infant Death Syndrome) completely and immediately disappeared."
He cites references that show that in 1970-75 there were approximately 25-30 million doses of whole-cell pertussis vaccine administered in Japan, and the Japanese government paid out 11 claims for "Sudden Death" in that time period under a vaccination compensation system (designed to encourage reporting of side effects).
He includes numbers on Sudden Unexpected Infant Death (SUD) and SIDS (a subcategory of SUD) in Japan:
"* Pertussis immunization age was raised to two years in 1975 The increase in the numbers of SIDS cases is attributable in large measure to increased recognition by forensic pathologists."
According to Morgan, the Japanese definition of SIDS includes the infant being under one year of age, so that "Ms Scheibner appears to have been unable to understand the simple fact that when the Japanese raised the pertussis immunization age to two years compensation for SIDS cases would inevitably cease since all SIDS cases occur at a much younger age....The only thing that disappeared in Japan was -claims- for SIDS vaccine damage. The actual -incidence- of SIDS cases, however, as demonstrated in the data above, not only continued but gradually increased."
Schiebner in turn has responded to Morgan's rebuttal. (incidentally, I can't find good provenance for either one of these documents; they turn up in web searches but I'm not entirely sure where they come from. These sites appear to be reprints, not original publications):
"SIDS is a rather rubbery diagnosis and the figures can be and are manipulated. However, the total infant deaths are a bit more difficult to manipulate. The definition of SIDS is a death of a child unexpected by history and with insufficient determination of cause of death. So, it depends on the degree of damage whether the infant death will be diagnosed as Sudden Infant Death Syndrome or pneumonitis, bronchiolitis, brain edema etc. With the increasing number of vaccines administered as part of the "routine" now, we shall see increasing numbers of babies with very serious reactions to vaccines and they will not be diagnosed as SIDS. We already see it in the epidemic of Shaken Baby Syndrome, when babies develop serious brain and other haemorrhages and die or remain seriously damaged and the parents are being accused of causing it by allegedly shaking their babies to death (Scheibner 1998)...."
"Torch (1982 and 1986 a,b) analysed the symptoms and postmortem findings in babies and small children after vaccination and described them in sufficient detail not to leave anything to imagination. Torch (1986b) concluded that 'Although many feel that the DPT-SIDS relationship is temporal, this author and others maintain a causal relationship exists in a yet-to-be determined SIDS fraction.'..."
"As far as the infant death rate or SIDS rate and vaccination schedule is concerned, it is quite clear that the shift of the lower vaccination limit to 2 years resulted in Japan zooming from 17th to first place in infant mortality rate: meaning from very high to the lowest rate in the world. This could hardly be interpreted to mean that only the number of vaccine deaths which were subject to compensation claims declined as the proponents of vaccination claim."
(There's a great deal more to Schiebner's rebuttal; I urge you to read the entire thing if you're interested.)
A pamphlet from the CDC points out that the immunization rate did drop in Japan, with predictable consequences:
"Three countries - Great Britain, Sweden, and Japan - cut back the use of pertussis vaccine because of fear about the vaccine. The effect was dramatic and immediate. In Great Britain, a drop in pertussis vaccination in 1974 was followed by an epidemic of more than 100,000 cases of pertussis and 36 deaths by 1978. In Japan, around the same time, a drop in vaccination rates from 70% to 20%-40% led to a jump in pertussis from 393 cases and no deaths in 1974 to 13,000 cases and 41 deaths in 1979. In Sweden, the annual incidence rate of pertussis per 100,000 children 0-6 years of age increased from 700 cases in 1981 to 3,200 in 1985."
The CDC goes on to say:
"One myth that won't seem to go away is that DTP vaccine causes sudden infant death syndrome (SIDS). This belief came about because a moderate proportion of children who die of SIDS have recently been vaccinated with DTP; and on the surface, this seems to point toward a causal connection. But this logic is faulty; you might as well say that eating bread causes car crashes, since most drivers who crash their cars could probably be shown to have eaten bread within the past 24 hours.
"If you consider that most SIDS deaths occur during the age range when 3 shots of DTP are given, you would expect DTP shots to precede a fair number of SIDS deaths simply by chance. In fact, when a number of well-controlled studies were conducted during the 1980's, the investigators found, nearly unanimously, that the number of SIDS deaths temporally associated with DTP vaccination was within the range expected to occur by chance. In other words, the SIDS deaths would have occurred even if no vaccinations had been given. In fact, in several of the studies children who had recently gotten a DTP shot were less likely to get SIDS. The Institute of Medicine reported that 'all controlled studies that have compared immunized versus nonimmunized children have found either no association . . . or a decreased risk . . . of SIDS among immunized children' and concluded that 'the evidence does not indicate a causal relation between [DTP] vaccine and SIDS.'"
An article on "The Complicated Task of Monitoring Vaccine Safety", by researchers from the FDA and CDC, also touches on the supposed SIDS/DPT link in its discussion of the VAERS system:
"In response to public concerns arising in the early 1980s about the safety of DTP vaccines, the National Institute of Child Health and Development conducted a large case-control study directed specifically at the question of the association between SIDS and DTP vaccination. This study did not support the hypothesis that DTP vaccine caused SIDS; in fact, it demonstrated a lowered risk for SIDS in children receiving DTP vaccine. (The authors of the report suggested that this lowered risk estimate was more likely the result of differences in baseline health status between children who did and did not receive scheduled vaccinations than to any protective effect of the vaccine against SIDS.)
"While this and other studies with similar results resolved the issue to the satisfaction of the scientific community, some members of the public have remained concerned about a possible connection between DTP vaccine and SIDS, citing the SIDS cases regularly reported to VAERS. In response to such concerns, FDA and CDC staff calculated the number of SIDS cases expected to occur by chance within a fixed number of days following immunization, accounting for the age-adjusted SIDS rate and the proportion of infants vaccinated at specific intervals, and determined that the number of cases reported for each time interval is far lower than would be expected to occur by chance alone. (Of course, these estimates may have been artificially lowered by underreporting of SIDS occurring shortly after vaccination.)
"Advocacy groups raising concerns about vaccine safety regularly point out that the reasoning described above for SIDS is flawed; since nearly all children are vaccinated, how do we know that the background SIDS rate is not partially or even largely caused by vaccination? It is true that there is no satisfactory unvaccinated control group to turn to, since the small group of children in the United States who go unvaccinated through the first year of life would almost certainly differ in important ways from those who do receive vaccinations on schedule. Well-designed studies to date, including the study described above, have used an alternative approach based on the assumption that if immunization caused sudden infant deaths, it would do so within a few days of immunization. This approach allowed researchers to compare children who died of SIDS with age-matched controls with respect to time since vaccination."
Ed Friedlander, a pathologist with an interest in alternative medicine, maintains a web page that takes a hard look at some of the literature cited by anti-vaccination advocates. He's generally not impressed. On the particular notion that DPT vaccination is tied to SIDS, as shown by Japanese evidence, he writes:
"After doing a computer search of the literature back to 1965, I am convinced that some activist simply made up the business about SIDS in Japan."
The SIDS Network has a page on immunization and SIDS, with quotes from a number of physicians, including some who have studied the issue:
"A number of epidemiologic studies have now been performed which look into the possible relationship of SIDS and DTP immunizations. The majority of studies, and the better studies, do not show a relationship. SIDS is most common between 2-4 months of age. Immunizations are routinely given at 2 and 4 months of age. Thus, by chance alone, one in eight SIDS babies will have died within a week of their baby shot. However, the larger studies do not show any greater frequency of SIDS near immunizations. The NIH collaborative study actually showed that fewwer SIDS victims had baby shots than controls.
"A number of years ago, our group took a different approach. We recorded the breathing pattern and heart rate of babies overnight the night before and after their DTP immunizations. We had three groups of infants: controls, SIDS siblings, and apnea of infancy (ALTE). There was no difference in the recordings the night after vs the night before the baby shot. In fact, there was a slight trend for breathing to be more regular after the baby shot."
BMJ, the British Medical Journal, published a study on 4/7/01 titled "The UK accelerated immunisation programme and sudden unexpected death in infancy: case-control study". This study looked at 303 SIDS cases in the UK and compared them with 1515 controls, matched by age and locality. The researchers interviewed parents and examined immunization records. From their discussion:
"More than a third of the deaths attributed to the sudden infant death syndrome in this study occurred between the ages of 2 and 4 months, around the time that most infants in the United Kingdom were receiving all three primary immunisations against Haemophilus influenza type b, diphtheria, tetanus and pertussis, and oral poliomyelitis. For this to be more than coincidental one would expect a higher immunisation uptake among the infants who died than among age matched surviving infants, or at least some temporal pattern compatible with a reaction to immunisation. The findings from this study suggest the opposite: fewer infants whose deaths were attributed to the sudden infant death syndrome were immunised, and fewer deaths occurred than expected, both within two days and two weeks of the last vaccination, with no particular pattern beyond this time period. The findings for the infants who died suddenly and unexpectedly but of explained causes, particularly infections, mirrored those for the infants whose deaths were attributed to the sudden infant death syndrome: lower compliance, no temporal effect, and no correlation between recent immunisation and signs or symptoms of illness. Our data suggest that even when potentially confounding factors, such as family mobility, are taken into account, immunisation does not contribute to the risk of the sudden infant death syndrome and may protect against it."
The researchers also note:
"Our data are consistent with the hypothesis that the standard primary course of immunisation may also have a non-specific protective effect on the risk of death in infancy, or alternatively that failure to begin the course may be a marker of family organisation where the sudden infant death syndrome may be more frequent."
This study appears to me to offer serious evidence that there is no causal relationship between DTP or other early vaccinations and SIDS.
I'm not a physician, so I'm not going to tell you what to do with this evidence. I will say that I see absolutely nothing in what I've been able to find that would make me worry about my child dying of SIDS due to a DPT vaccination. On the other hand, there is a very real chance of whooping cough or tetanus in a rural area like this. I think the choice is clear.