Changes in Rabies Postexposure Prophylaxis Regimen

A revised guidelines has been proposed for the administering of rabies post-exposure prophylaxis regimen - basically, a one-less injection schedule, reducing from five doses recommendation: day 0, 3, 7, 14 and 28 to four doses recommendation: day 0, 3, 7 and 14.

Read the revised recommendations published in current CDC Morbidity and Mortality Weekly Report (19 March 2010). Click here for full access.

The rationale for this change as given in the text is because:

1. Of the >55,000 persons who die annually of rabies worldwide, the majority either did not receive any post-exposure prophylaxis (PEP), received some form of PEP (usually without Rabies Immunoglobulin) after substantial delays, or were administered PEP according to schedules that deviated substantially from current ACIP or World Health Organization recommendations.

For example, a review of a series of 21 fatal human cases in which patients received some form of PEP indicated that 20 patients developed signs of illness, and most died before day 28. In such cases, in which widespread infection of the central nervous system occurs before the due date (i.e., day 28) of the fifth vaccine dose, the utility of that dose must be nil.

In other words, it is timing of the first dose and the compliance to subsequent scheduled injections that is more important rather than whether the additional fifth dose is given.

2. Secondly, of the more 1,000 persons in the United States that received rabies prophylaxis annually of only 3 or 4 doses, none has the resulting documented cases of human rabies, even though >30% of these persons likely have exposure to confirmed rabid animal.

3. Even in the worldwide scenario, although human PEP failures have been reported very rarely, (even in cases in which intervention appeared both prompt and appropriate), no cases have been attributed to the lack of receipt of the fifth human rabies vaccine dose on day 28.

Personally, these changes are welcomed because from my previous experience, to call the patients back to the emergency department for further doses of rabies immuno-globulin itself is a challenge (not to mention the cost saved for reducing one additional dose)! More doses = less compliance.