The currently available anti-rabies vaccines can be grouped on the basis of the substrate used to grow the vaccine virus strain.

➡️Neural Tissue Vaccine (NTV)

The Neural Tissue Vaccines (NTV) have been effective but as it contains less antigen, daily injections for 10-14 days followed by boosters are required to produce a protective level of antibody. The production of NTV has been stopped in Egypt in view of serious Neuroparalytic

reaction.

➡️Tissue Culture Vaccines (TCV)

Three types of vaccines that are currently available are:

· Human diploid cell strain vaccine (HDCV)

· Purifed chick embryo cell vaccine (PCEC)

· Purified Vero cell vaccine (PVRV)

As recommended by the WHO Expert Committee on Rabies (1992), the course for post-exposure

prophylaxis should consist of five injections (Day O, 3, 7, 14 and 28) and the sixth injection

(D90) should be considered as optional. (Should be given to those individuals who are immunologically deficient, and are at the extremes of age and on steroid therapy). Day 0 indicates date of first injection.

The dose of the vaccine per injection is 1 ml for HDCV and PCEC vaccines and 0.5 ml for PVRV irrespective of age and weight of vaccine.

➡️Indications: All cases of animal bites, irrespective of severity of exposure, require the same number of injections and dose per injection. The Category III requires administration of rabies immunoglobulins.

➡️Site of inoculation: The deltoid region is ideal for the inoculation of these vaccines. Gluteal region is not recommended because the fat present in this region retards the absorption of antigen and hence impairs the generation of optimal immune response.

➡️Protective level of anti-rabies antibody: Humoral antibodies are believed to play important role

in protection against rabies and a titre of 0.5 i.u./ml or more in serum is considered as protective.

➡️Adverse effects with tissue culture vaccines: The tissue culture vaccines are widely accepted as the least reactogenic rabies vaccines available today. Various studies have now shown that adverse effects can be either general in nature or allergic in origin. The general adverse reactions include sore arm, headache, malaise, nausea, fever and localized edema at the site of injection.

Symptomatic treatment may be needed.

➡️Purified Duck Embryo Vaccine (PDEV)

A purified version of duck embryo vaccine (PDEV) has been prepared because of the excellent yield of rabies virus obtained from embryonated eggs and the economy in production. The PDEV has been claimed to be as immunogenic and safe as other anti-rabies Tissue Culture Vaccine. Its dosage and schedule is similar to that of tissue culture vaccine.