Background: The increasing complexity of contemporaneous exposure to several combination vaccines (especially childhood vaccines) makes the assessment of the effects due to a single vaccine more difficult to identify. As no placebo-controlled trials are likely to be conducted on scheduled childhood vaccines ever again, answers to new questions on the effects must come from sources other than new experimentation.

Objective: To describe the structuring of available information on the effects of vaccines into a vaccines library.

Methods: We envisage the vaccines library being built as an international collaborative and interdisciplinary effort, developed stepwise. Data are likely to be a mix of existing and to-be-collected. For example, recent bio-terrorist threats have re-awakened interest in vaccines against diseases which were eradicated (e.g. smallpox), near eradication (polio) or very rare (anthrax). The maintenance of a knowledge base on these vaccines may facilitate swifter reactions to sudden natural or man-made threats in the future. The Library could be structured with the following databases: Reviews of human vaccine studies. Single human vaccine studies. Reviews of animal vaccine studies. Single animal vaccine studies. Links to vaccine websites. References to reports on vaccines (e.g. WHO) and technical reports of studies. Institutional or personal archives (paper, sound and/or video).

We envisage that each item would have a consumer synopsis.

Conclusions: An independent source of critically appraised evidence on vaccines in required.

References: 1. Jefferson T. Informed choice and balance are victims of the MMR-autism saga. Lancet Infect Dis. 2004; 4: 135-36. 2. Horton R. The Lessons of MMR. The Lancet. 2004; 363 (9411): 747-9.