 Rabies is present on all continents where U.S. military personnel deploy, including countries where malaria is also endemic and where U.S. military personnel are required to take malaria prophylaxis. Rabies post-exposure prophylaxis in unvaccinated individuals who are not on malaria prophylaxis consists of four, 1.0-mL intramuscular IM injections of the purified chick embryo cell PCECV rabies vaccine on days 0, 3, 7, and 14. The current Advisory Committee on Immunization Practices ACIP guidelines recommend that exposed persons who are taking malaria prophylaxis should receive a fifth dose of rabies vaccine 28 days after the exposure. These guidelines do not differentiate between drugs used for malaria prophylaxis This study will administer the post-exposure regimen to volunteers from a US population of military age who are taking one of three malaria prophylaxis regimens or no malaria prophylaxis. The goal of this study is to asses if individuals on malaria prophylaxis achieve the required rabies titer after completion of the four dose regimen. 