Postexposure Rabies Prophylaxis Completed in 1 Week: Preliminary Study

Abstract

Patients exposed to a rabid animal often travel long distances to receive postexposure prophylaxis (PEP), which requires 4 or 5 visits. Reducing the number of clinic visits would not only reduce costs for the patient but may also help increase compliance to receive complete PEP. We made an effort to develop PEP completed in 1 week. We administered the 4-site intradermal injections of 0.1 mL of purified Vero cell rabies vaccine to the deltoids and thighs on days 0, 3, and 7, with and without equine rabies immunoglobulin (40 IU/kg). A control group received the World Health Organization-approved and widely used Thai Red Cross regimen (2-site intradermal injections on days 0, 3, and 7 and 1 injection on days 28 and 90) with equine rabies immunoglobulin. We then determined rabies neutralizing antibody (NAb) up to day 360. Geometric mean titers for subjects receiving the 4-site intradermal regimen, with or without equine rabies immunoglobulin, had significantly higher NAb values than did the control group on day 14 and 28 (P<.001). All subjects in all groups had a NAb value > or =0.5 IU/mL on days 14 and 28. The percentages of subjects who had a NAb value > or =0.5 IU/mL from days 0 through 360 were not significantly different among the 3 groups. After any PEP regimen, World Health Organization recommendations require a NAb value > or =0.5 IU/mL on days 14 and 28. The 1-week PEP regimen, therefore, appears promising. It increased immunogenicity over the 2-site intradermal schedule, and it is convenient and can be used in small clinics, because it consumes almost the entire supplied vaccine ampoule volume.