Enhanced antibody response to rabies virus in patients with neurologic complications following brain tissue-derived rabies vaccination.

Sera from 26 patients with major neurologic complications, 19 patients with minor complications and 23 patients with no complications induced by Semple rabies vaccine were assayed for neutralizing antibody to rabies virus. Seroconversion to the protective level (greater than or equal to 0.5 IU/ml) was found in 21 of 22 patients (95%) with major complications, and in 7 of 19 (37%) with minor complications, occurring during the first 14 days of vaccination. This was in contrast to 42% (5/12) seroconversion in uncomplicated recipients after 14 daily injections. After initiation of dexamethasone treatment, 13 of 18 patients with major complications showed a diminution in their rabies antibody levels on day 4 or 7.

Humoral and cell-mediated immune responses to various economical regimens of purified Vero cell rabies vaccine.

Purified Vero cell rabies vaccine (PVRV) is a new effective but inexpensive tissue culture rabies vaccine for human use. We investigated if the cost of immunization with PVRV could be further reduced by intradermal immunization. Fifty-eight subjects with low-risk exposure to rabies were randomized into 4 groups to receive full-dose (0.5 ml) intramuscular injection of PVRV on days 0, 3, 7, 14 and 28 or 4, 2 or 1 intradermal injections of PVRV (0.1 ml) on days 0, 3, and 7, followed by another intradermal injection on day 28. Neutralizing antibodies and specific cell-mediated response (CMIR) were sequentially followed up to day 36. The antibody levels in the intradermal groups increased with the number of injection sites and the levels achieved by the 2-site i.d. regimen were not significantly different from those obtained by the full-dose i.m. even though only 1/3 of the amount of PVRV was used. Specific CMIR occurred 1 week sooner in the 2 and 4-site i.d. regimens than the full-dose i.m. We therefore recommended that our 2-site i.d. regimen of PVRV should be further tested with a view to substituting it for the more expensive full-dose i.m. regimen in order to further reduce the cost of rabies prophylaxis particularly in the developing countries.