Immunization Safety Review: Multiple Immunizations and Immune Dysfunction (2002)
Chapter: Appendix D Methods of Identifying the Literature for the Causality Agreement
Appendix D
Methods of Identifying the Literature for the Causality Assessment
To evaluate the hypothesis on multiple immunizations and immune system dysfunction, the committee collected information from several sources. At an open scientific meeting in November 2001, academic researchers gave presentations on specific scientific issues germane to the topic. All information presented to the committee at that meeting can be viewed on the project website (www.iom.edu/imsafety). An extensive review was performed of the published, peer-reviewed scientific and medical literature pertinent to the hypothesis.
Search Strategy for the Causality Assessment
To inform the committee’s causality assessments, the following searches were performed. As epidemiological studies carry the most weight in a causality assessment, all searches were limited to human subjects.
Diabetes A search for relevant articles was conducted on PubMed using the MeSH term “diabetes mellitus, insulin dependent” with the terms “vaccin*” or “immunization*” in the MeSH field. The search was further limited to articles in English.
Asthma A search was conducted on PubMed. The terms “vaccines” OR “immunizations” were combined with the term “hypersensitivity” in the MeSH field. This search was then combined with NOT “cancer” OR “occupational diseases,” also in the MeSH field. The search was further narrowed by combining the results with “epidemiologic methods” in the MeSH field, and limiting it to studies in English. A total of 363 articles were found.
Heterologous Infection To examine the heterologous effects of vaccines, several searches were conducted on PubMed. In the first, the terms “vaccines/adverse effects” were combined with “viruses/etiology” in the MeSH field. The search was further limited to studies in which “vaccines/adverse effects” had to appear as a MeSH major topic—a MeSH term that is one of the main topics discussed in the article.
A second search for articles pertaining to heterologous effects of vaccines combined “pneumococcal OR polio OR diphtheria OR tetanus vaccine” with “invasive bacterial disease.” A similar search combined “vaccine/adverse ef
