Responses to Rabies Vaccine in Adults With or Without Antibiotics

Inclusion Criteria: * Healthy individuals aged 18-49 years. * Able to understand and give informed consent. * Women of child-bearing potential (not surgically sterile via tubal ligation, bilateral oophorectomy or hysterectomy or who are not postmenopausal for ≥1 year) must agree to practice adequate contraception that may include, but is not limited to, abstinence, monogamous relationship with vasectomized partner, barrier methods such as condoms, diaphragms, spermicides, intrauterine devices, and licensed hormonal methods for 28 days before and 28 days after Rabies vaccination. Exclusion Criteria: * Receipt of the following: * Receipt of blood products 3 months prior to vaccination or expected receipt through 12 months after vaccination. * Receipt of any live virus vaccines within 28 days prior to vaccination or expected receipt within 28 days after vaccination. * Receipt of any inactivated vaccine within 14 days or expected receipt within 14 days after vaccination. * Receipt of any antibiotic 3 months prior to vaccination or expected receipt 28 days after vaccination. * Receipt of probiotics and prebiotics 3 months prior to vaccination or expected receipt 28 days after vaccination. * Receipt of proton pump inhibitors, H2 receptor blockers, or antacids 3 months prior to vaccination or expected receipt 28 days after vaccination. * Presence of co-morbidities or immunosuppressive states such as: * Chronic medical problems including (but not limited to) insuli…