A summary of these agencies' guidelines to date (March 2001) on xenotransplantation and the U.S. regulatory bodies which have been created to foster public discussion on the issues surrounding xenotransplantation

U.S. federal government agencies have issued several sets of guidelines on xenotransplantation:

• The Public Health Service division of the Department of Health and Human Services (DHHS) first issued Guidelines on Infectious Disease Issues in Xenotransplantation in September 1996, with periodic updates over the years. The latest update was published in January 2001. These guidelines were jointly developed by the Centers for Disease Control and Prevention (CDC), Food and Drug Administration (FDA), Health Resources and Services Administration (HRSA), National Institutes of Health (NIH), and the Office of the Assistant Secretary for Planning and Evaluation of the DHHS. They outline xenotransplant protocol issues, including animal sources for xenotransplantation, clinical issues and public health needs. They also detail the special requirements of the informed consent process for prospective xenotransplant recipients, as well as describe the development of a pilot project for a National Xenotransplant Database.

• In February 2001, the FDA's Center for Biologics Evaluation and Research division published its Draft Guidelines for Industry: Source Animal, Product, Preclinical, and Clinical Issues Concerning the Use of Xenotransplantation Products in Humans. These guidelines reiterate much information from the PHS Guidelines, but also detail more specific advice regarding xenotransplant products and procedures. This committee also issued Guidance for Industry: Public Health Issues Posed by the Use of Nonhuman Primate Xenografts in Humans, as well as Guidance for Industry: Precautionary Measures to Reduce the Possible Risk of Transmission of Zoonoses by Blood and Blood Products from Xenotransplant Product Recipients and Their Contacts.

U.S. federal agencies have set up two bodies to facilitate public discussion of the issues surrounding xenotransplantation:

• In 1997, the FDA's Biological Response Modifiers Advisory Committee created a Subcommittee on Xenotransplantation, which holds open public meetings to discuss the scientific, medical, social, ethical, and public health concerns surrounding xenotransplantation.

• The Department of Health and Human Services created the Secretary's Advisory Committee on Xenotransplantation (SACX) in July 1999. The SACX is comprised of 18 voting members from fields including xenotransplantation, epidemiology, virology, microbiology, infectious diseases, veterinary medicine, immunology, law, bioethics, patient advocacy, and animal welfare. It also holds open public meetings to discuss xenotransplantation's public health implications.

The process of educating a subject before a clinical research procedure is known as informed consent. It is important for the patient to fully understand the risks as well as the potential benefits before agreeing to undertake any experimental procedure.

• The Department of Health and Human Services has issued General Guidelines for Informed Consent, which outline the information the subject must be provided, including any potential risks and/or benefits, as well as any alternative procedures that could benefit the patient. Signing an informed consent document does not mean that the subject has relinquished his legal rights or released the sponsor from liability.

• The Declaration of Helsinki describes the World Medical Association's guidelines for biomedical research involving human subjects. While it acknowledges "Medical progress is based on research which ultimately must rest in part on experimentation involving human subjects" the document also states "The subjects must be volunteers and informed participants in the research project."