Rabies immune globulin is a product that is lifesaving to unvaccinated individuals exposed to the rabies virus. Rabies immune globulin is made from plasma from immune donors. Currently the only practical method to obtain this plasma is to immunize normal volunteer Source Plasma donors and collect their plasma while titers are adequate. The use of rabies vaccine for immunization of normal Source Plasma donors is currently limited to a level that, while protective for the individual, is unsuitable for production of rabies immune globulin.

The objective of this study is to obtain efficacy and safety data regarding the rabies boostering program to demonstrate that:

1. Rabies immune plasma production can be substantially increased by giving booster doses to previously immunized donors whose titers are below 10.0 IU/mL.
2. It is safe for normal Source Plasma donors to receive booster doses of rabies vaccine on a regular basis.

This study utilizes two rabies vaccines approved by the FDA, Imovax® (Sanofi-Pasteur) and RabAvert® (Novartis).

Inclusion Criteria:

• Meet requirements for Source Plasma donors
• Completed initial series of rabies antibody injections with no serious adverse events for at least 90 days prior to enrollment
• Compliance with program requirements
• Signed informed consent

Exclusion Criteria:

• Failure to meet requirements to be Source Plasma donor
• Non-compliance with the program
• Experience a serious adverse reaction

Source Plasma Donors. Donors must meet FDA and CSL Plasma requirements to be Source Plasma Donors. Donors had previously participated in CSL's rabies vaccine immunization program.