The Vaccine Safety Committee, established by the Institutes of Medicine, has ruled that the evidence proves, or favors, a causal relation between vaccines and the following adverse effects:

• anaphylaxis (a sudden, potentially life-threatening systemic allergic response) caused by several vaccines
• polio and death caused by the polio vaccine
• thrombocytopenia (a decrease in the number of platelets, the cells involved in blood clotting) caused by the measles vaccine
• death caused by the measles vaccine
• acute arthritis caused by the rubella vaccine
• acute encephalopathy after DTP
• shock and unusual shock-like states after DTP
• chronic arthritis after rubella vaccine
• Guillain-Barré syndrome after DT and polio vaccines.

Long-Term Reactions
Deep controversy also surrounds the issue of delayed or long-term reactions, because these do not have a clear causal link to vaccines. In vaccine-industry jargon, they are not "temporally related" - that is the definition of a delayed reaction. For example, how do we know that the increased number of ear infections in a population of vaccinated children, or in any individual child, was caused by the vaccine? No one has studied this question. How do we know that the rise in attention disorders in school-age children has a relationship to vaccines? It would seem to be a logical conclusion, but no one has studied vaccinated versus unvaccinated children. Parents must make judgments in this area based on the experience of other parents and practitioners whose children and patients have not been vaccinated.

In general, such parents and practitioners agree that their children are healthier, and suffer fewer recurrent infections, than their vaccinated counterparts. This may help reassure parents who choose not to vaccinate, but it obviously carries no scientific weight.

Critics of vaccinations have asserted that vaccines are capable of causing recurrent infections in children because they weaken the immune system. They say that the dramatic rise in ear infections, allergies, and asthma in children can be attributed (at least in part) to the damaging effects of vaccines. The incidence of asthma, the most serious and life-threatening of these conditions, has steadily increased in the modern era since the introduction of vaccines. Just during the period 1980 through 1989 the prevalence rate of self-reported asthma in the United States increased 38 percent, and the death rate for asthma increased 46 percent (Centers for Disease Control, 1992). Just in the five years from 1985 through 1990, projected estimates for asthma’s medical costs increased 53 percent. The total estimated cost of asthma rose from $4.5 billion to $6.2 billion, or 1 percent of all US health-care costs (Weiss et al., 1992). This dramatic increase has been attributed to increased exposure to environmental pollutants, and to the toxic effect of asthma medications themselves, but the increasing burden on the immune system caused by vaccines could also be responsible.