Administering a Rabies vaccine
The combination of local treatment of the wound, passive immunization with Rabies lmmunoglobulin (RIG) and vaccination is recommended for all severe exposure (category 111) to rabies. Prompt and thorough cleansing of the wound, and administration of purified Equine or Human Rabies lmmunoglobulin (ERIG or HRIG) and cell culture rabies vaccine immediately after exposure virtually guarantee complete protection, and the risk of post-exposure treatment complications is much lower than with brain-tissue vaceines.
Intramuscular schedule:
All intramuscular injections must be given into the deltoid region or,
in small children, into the anteriolateral area of the thigh muscle.
The vaccine should never be administered in the gluteal region.
The most widely used WHO scheme calls for a single 1.0 ml dose IM, administered in the upper deltoid (anteriolateral area of thigh for children) on day 0, 3, 7, 14 and 30 with an optional further dose on day 90.
Often the day 90 dose is omitted except in those also given passive immunisation with RIG (usually categ III bite).
The gluteal region is not recommended on account of high fat content in this region which retards the absorption of the vaccine.
Age and/or weight & dose:
Neonates can be given the anti-rabies vaccine without any additional side effects vis-a-vis older children or adults. Modern tissue culture rabies vaccine should not be given in reduced dosage irrespective of the age and/ or weight.
The dosage schedule for the modern tissue culture vaccine remains same for all age groups.
Important considerations while administering Rabies lmmunoglobulin(RIG)
Depending on how severe the bite is, Human or Equine Rabies lmmunoglobulin (HRIG or ERIG) is administered on day 0. If possible, RIG should be administered on the day of injury / contact, at the same time as the f irst dose of the vaccine.
If such simultaneous prophylaxis was not given,i.e. if only the vaccine was given at the prescribed interval, then it is only meaningful to administer RIG up to the 8th day after the first injection of the vaccine. The prescribed dosage of RIG must not be exceeded even if commencement of simultaneous prophylaxis is delayed.
Dosage: Human Rabies lmmunoglobulin (HRIG) is given as 20 I.U./ kg.
Equine Rabies lmmunoglobulin (ERIG) is given as 40 I.U./ kg.
Both are injected into and around the wound with any surplus given by deep IM injection. If the calculated volume is inadequate for the injections of all wounds, dilute it in normal saline to make up a sufficient volume.
Disregard the old recommendation that half of the calculated volume of RIG should be injected into the wounds and half I.M.
Site of injection:
Wound infiltration is the most important part of RIG administration. If any of the dose remains after infiltration, it can be given IM into the anteior thigh, and if necessary divided between the two thighs. Injections should not be given into the gluteal region.
Method of wound infiltration:
Caution is needed if injecting into a tissue compartment, e.g. fingerpulp. Excess fiuid can result in increased compartmental pressure and lead to necrosis. Care is needed to avoid RIG seeping out of wounds during infiltration. If such a loss does occur, the volume should be estimated and replaced.
The use of intradermal skin tests before ERIG treatments:
The ID skin test detects lgE mediated Type 1 hypersensitivity, a reaginic response to previous exposure into the antigen .