Responses to Rabies Vaccine in Adults With or Without Antibiotics

The use of antibiotics changes micro-organisms in the intestines which may impact the body's vaccine immune response and alter the effectiveness of the rabies vaccine. There will be two randomized groups (1:1 randomization). Group A will start taking an antibiotic regimen by mouth 3 days prior to vaccination and continue taking antibiotics the day of rabies vaccination and one day after vaccination for a total of 5 days. Group B will only receive the rabies vaccination and will not take any antibiotics. The dosage of each antibiotic is taken from their respective package inserts and does not exceed the maximum dose allowed for each antibiotic. The purpose of the study is to look at immune response after rabies vaccination with or without the use of antibiotics from day of vaccination to 28 days post vaccination in both groups.