Risk of sudden infant death syndrome after immunization with the diphtheria-tetanus-pertussis vaccine

Sudden infant death syndrome and diphtheria-tetanus-pertussis-poliomyelitis vaccination status

Because diphtheria, tetanus, pertussis and poliomyelitis vaccine is routinely given during the period of highest incidence of sudden infant death syndrome (SIDS), we carried out a retrospective case-control study to assess whether such vaccination increased the risk of SIDS. The vaccination status of 118 SIDS and 332 control children, matched for sex, date of birth and age of the victims at death, was compared: the victims of SIDS were not significantly more often vaccinated than control children, the odds ratio was estimated at 1.9 with a 95% confidence interval from 0.9 to 3.9. There was a statistical difference between vaccination status of SIDS cases and controls aged less than three months. Nine percent of SIDS cases under 3 months had been vaccinated whereas the matched controls had not. In our study DTCP vaccination was not a risk factor for SIDS; although more of the SIDS infants less than 3 months of age had been vaccinated. This result however, concerns only one subgroup of the population studied and needs to be confirmed with another study of only SIDS infants less than 3 months of age, because DTCP vaccination was not a risk factor for SIDS when considering the total sample of the study.

Whole-cell and acellular pertussis vaccines

OBJECTIVE

To provide a review of pertussis vaccines, including information on efficacy, adverse reactions, and antibody production following administration of both whole-cell and acellular pertussis vaccines.

DATA SOURCES

A MEDLINE search and extensive review of journals was conducted to identify the information for this review.

DATA EXTRACTION

Pertinent studies reporting experience with pertussis vaccinations were reviewed.

DATA SYNTHESIS

The differences in efficacy, adverse reactions, and antibody responses between whole-cell and acellular pertussis vaccines are emphasized. The status of acellular pertussis vaccination in the US is defined.

CONCLUSIONS

Acellular (chemically detoxified or recombinant) pertussis vaccine formulation appears to cause fewer adverse reactions than whole-cell vaccine in most studies. Clinical efficacy and safety in the very young has not been well established. Thus, acellular pertussis vaccine is reserved for the 4th and 5th doses in the US. Oral or intranasal formulations of the pertussis vaccine are being evaluated.

Immunization status and demographic characteristics of New Zealand infants in the first 6 months of life

In the Royal New Zealand Plunket Society's 1990-91 cohort study, of 3902 children, 985 (25.2%) had fallen behind the immunization schedule by 6 months of age. These children were more likely to be from lower socio-economic groups or to have mothers who were older, with high or low education, or of higher parity. The infants were also more likely to be from non-European families, or to have unemployed fathers. Eight hundred and ten (82.2%) of the incompletely immunized children at that age could be brought up-to-date with their immunizations by a single visit to the doctor. The most common reason for delaying immunization was that the baby was sick. This was a false contraindication in 69.2, 79.0 and 78.4% of these children at the 6 week, 3 month and 5 month immunization, respectively.

Effect of diphtheria-tetanus-pertussis immunization on prolonged apnea or bradycardia in siblings of sudden infant death syndrome victims

To determine whether the incidence of apnea or bradycardia increased after the first diphtheria-tetanus-pertussis (DTP) immunization in 100 subsequent siblings of victims of sudden infant death syndrome, we examined data obtained from floppy disk recordings attached to apnea-bradycardia monitors for episodes of apnea lasting 15 seconds or longer and episodes of bradycardia lasting 10 seconds or longer. The data were divided into three periods: (1) 10 days before the first DTP immunization was received (pre-DTP period), (2) 10 days immediately after the DTP (DTP period), and (3) 10 days after the DTP period (post-DTP period). Seventeen infants had at least one episode of prolonged apnea or prolonged bradycardia either before or after the 30-day study period (eight before only, eight after only, and one before and after). None of the infants had episodes of apnea lasting 15 seconds or more or bradycardia lasting 10 seconds or more during the pre-DTP or DTP period. One episode of apnea, 16 seconds long, and one episode of bradycardia lasting 11 seconds occurred in the post-DTP period. These results failed to confirm the clinical impression that DTP immunizations are associated with an increased frequency and severity of prolonged apnea. They also place in question the utility of assessing an infant's response to a DTP immunization to determine continued risk of apnea and bradycardia before home monitoring is discontinued.

Sudden infant death syndrome: a crisis for parents and health professionals

A study of the social impact of Sudden Infant Death Syndrome (SIDS) in 40 families in Ireland (40 mothers: 29 fathers and 78 siblings) revealed a profound influence on family function. Less than half the parents felt an acceptance of the loss at a mean interim of 2.9 years post SIDS. Family dysfunction was manifested by marital problems and prolonged grief reactions. Interpersonal support through family, friends, relatives or neighbours appropriately assisted a third of families. Medical information when provided to parents contributed to a more normal grief process, but lack of postmortem information contributed to pathological or unresolved guilt in a third of parents and anger in nearly half the sample. Health professional and voluntary aftercare at community level was inconsistent in meeting parents' need for information, advice and support. A primary, preventive health care approach, based on a co-ordinated policy of aftercare to SIDS families, at hospital and community level is recommended to facilitate parents' resolution of grief, and counteract the onset of adverse psychosocial effects.

Pertussis vaccines

Concern over adverse reactions temporally associated with whole cell pertussis vaccine and advances in the understanding of the Bordetella pertussis organism have led to a new generation of more purified acellular vaccines. The biology of the pertussis organism, epidemiology of disease, vaccine development over the decades, and vaccine efficacy and adverse reaction data from whole cell and acellular vaccine trials are presented. Questions that remain to be answered before acellular vaccine replaces conventional vaccine are defined, and future studies addressing these questions are proposed.

Pertussis vaccine and injury to the brain

A syndrome of pertussis vaccine encephalopathy was first reported 56 years ago. Analysis of the recent literature, however, does not support the existence of such a syndrome and suggests that neurologic events after immunization are chance temporal associations of neurologic conditions that occur in the target age group, even in the absence of immunization. Population-based studies do not prove a causal relationship with acute encephalopathy. There are no consistent neuropathologic findings suggesting a specific pathophysiologic process, and hypotheses concerning possible mechanisms of damage are not supported by reproducible studies in children. No acceptable animal model exists. There clearly is an increased risk of a convulsion after diphtheria-tetanus-pertussis immunization but no evidence that this produces brain injury or is a forerunner of epilepsy. Studies have also not linked immunization with either sudden infant death syndrome or infantile spasms.

Surveillance. Information for action

Success in immunization requires success in developing an adequate information base. While special studies are important, there is no substitute for surveillance systems. Such systems help evaluate health impact, monitor trends in reported disease and adverse events, and identify areas for more intense investigation. Surveillance data alone have played major roles in immunization strategy changes. Successful surveillance relies on cooperation by health care providers and health departments. While filling out forms and reporting cases may be viewed as a burden by some, such information in the aggregate becomes an important part of the knowledge base used to refocus implementation efforts and potentially to change strategies. Reporting by all physicians is particularly important when reported cases lead to aggressive control actions such as outbreak control. Rapid reporting even when cases are not confirmed can help health departments ensure that needed laboratory specimens are collected and allow control measures to be undertaken before disease containment becomes difficult. In conclusion, any immunization program worth instituting is worth monitoring. Surveillance represents constant vigilance to ensure effective control or elimination of disease.

Chiropractors for and against vaccines

The publications of philosophically conservative chiropractors document their allegiance to a posture of hostile opposition to health prevention based upon immunization procedures. The challenge to medical anthropology is to make sense of what seems scientifically senseless. This paper attempts to come to an understanding of this position by tracing professional attitudes which are derived from a history of political and economic conflict with the American medical establishment, which emanate from an explanatory model of disease causation that preserves a nineteenth century monocausal theory, and which reflect a process of cultural schizmogenesis. In preserving these heretical medical beliefs, conservative chiropractors, who are trained in the basic medical sciences, defend themselves by basing their opposition to immunization upon imperfections in vaccines that relate to the efficacy, safety and necessity of immunizations. Further, they persist in a belief that chiropractic spinal manipulation provides an alternative method for achieving immune status. This belief has not been subjected to testing in clinical trials or laboratory experiments, and thus becomes a matter of belief rather than of scientific verity. A refusal to advocate or submit to vaccines serves conservative chiropractors as an understandable cultural symbol, but it is a symbol with sinister health costs to those who translate it into non-immune status in a world otherwise still hostage to disease-producing organisms.

Sudden, unexpected, natural death in childhood

One thousand nine hundred and fifty four autopsies performed at British Columbia's Children's Hospital during a 7-year period were reviewed to determine the causes of sudden unexpected natural death in the age group from birth to 17 years. Of the 126 cases found, the largest group, 86 cases, was sudden infant death syndrome (SIDS). Nine deaths were the result of infection: 4 cases of H. influenza meningitis, 2 cases of meningococcemia, 2 cases of acute epiglottitis, and 1 case of necrotizing tracheobronchitis. Epilepsy, ruptured AV malformations, and brain tumors combined to make up an equally large group of 9 cases. Cardiac lesions were the third largest group, 6 cases. The three groups that posed the most difficulty in assigning a cause of death were (a) the group that were like SIDS yet had other confounding features, (b) the group in which metabolic death was suspected but not proven, and (c) death in epilepsy.