Safety and immunogenicity of chromatographically purified Vero cell rabies vaccine for intradermal pre- and post-exposure rabies prophylaxis.

UNLABELLED: Improved rabies pre- and post-exposure prophylaxis (PrEP and PEP) in developing countries uses an economic multi-site intradermal vaccination. AIM: To evaluate immunogenicity of chromatographically purified Vero cell vaccine (CPRV) for intradermal PrEP and PEP. METHOD: The subjects received conventional PrEP with CPRV or PVRV in PrEP study or received intradermal PEP with CPRV or PVRV and rabies immunoglobulin in PEP study. RESULT: All subjects who received PrEP with CPRV had protective neutralizing antibody (Nab) titers (≥0.5 IU/ml) 14 days after completing vaccination. In PEP study, Nab titers in the CPRV groups reached ≥ 0.5 IU/ml in all subjects by day 14 through day 90 after vaccination. The geometric mean titers of Nab in the CPRV groups had significantly higher titers than the PVRV group on day 14 through day 365 (p < 0.05). No serious adverse reactions were observed. CONCLUSIONS: CPRV is safe and immunogenic when given for intradermal PrEP and PEP.

Postexposure rabies prophylaxis completed in 1 week: preliminary study.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Problems in human rabies post-exposure prophylaxis management.

This is a prospective study of problems encountered with rabies-exposed patients in an animal bite clinic in a rabies endemic region. Five hundred successive patients were analyzed. The study focused mainly on issues that are not well covered in current WHO and US-CDC rabies manuals. Those dealing with immunoglobulin administration, managing severe and unusual injuries, logistic and financial issues headed the list. Animal bite patients often present challenging problems, which are not or inadequately addressed in official publications. Experience and good clinical judgment are essential in preventing human rabies.

Common dilemmas in managing rabies exposed subjects.

Health care staff managing rabies exposures in a canine endemic or epidemic environments are often faced with having to make treatment decisions where there are no firm guidelines from WHO or local public health authorities. We have made an attempt to identify several common events that presented to a busy animal bite clinic in a rabies endemic country. Leading experts in this field have been queried about their management opinions in such situtions. They have revealed little uniformity. It appears that there is still much controversy and lack of evidence-based approach from international authorities, and that more research and data collection is needed to resolve some of these issues and provide better guidelines in this field.