Failure has often been attributed to the delay in receiving treatment (greater than 72 hours post-exposure), the level of exposure, and/or the duration of treatment (lack of adherence to the 28-day regimen). In addition, since the time and level of non-occupational exposures are self-reported, there is no absolute data on the administration timeframe to which PEP would be efficacious. The standard antibody window period begins after the last day of PEP treatment. People who received PEP are typically advised to get an antibody test at 6 months post-exposure as well as the standard 3 month test. The antiretroviral regimen used in PEP is the same as the standard highly active antiretroviral therapy used to treat AIDS. People initiating nPEP treatment typically receive a 28-day starter pack, as opposed to a 3-7 day starter pack, to facilitate strong medication adherence. They should also be counseled on the unpleasant side effects including malaise, fatigue, diarrhea, headache, nausea and vomiting. People at high risk for re-exposure due to unprotected intercourse or other behavioral factors should be given PrEP, which would begin immediately after the completion of the nPEP treatment course. Inversely, if a medically-adherent patient is already on PrEP upon non-occupational exposure, nPEP treatment is not necessary. For exposure to hepatitis A, human normal immunoglobulin (HNIG) and/or hepatitis A vaccine may be used as PEP depending on the clinical situation. If the person exposed is an HBsAg positive source (a known responder to HBV vaccine) then if exposed to hepatitis B a booster dose should be given. If they are in the process of being vaccinated or are a non-responder they need to have hepatitis B immune globulin (HBIG) and the vaccine. For known non-responders HBIG and the vaccine should be given whilst those in the process of being vaccinated should have an accelerated course of HBV vaccine. Persons exposed to hepatitis C should get monthly PCR, and if seroconversion occurs then interferon, with possible ribavirin. A 60-day course of oral ciprofloxacin should be given when exposure to anthrax is suspected.