The aim of vaccination is to produce an immune status as quickly as possible so that the virus will not become established in the peripheral nerve along which it will travel to the central nervous system. Serum antibodies appear approximately 7 days after vaccination. Immunity is less effective after a nerve infection has been established.
Combined vaccine and immunoglobulin/serum treatment offers the best prophylaxis of rabies in exposed persons. Anti–rabies serum prevents replication of the virus at the site of the bite. It should be given as promptly as possible after a sensitivity test, irrespective of the interval between exposure and beginning of the treatment.
Human rabies Immunoglobulin
Human rabies Ig (HRIG) has now replaced equine anti–rabies serum in many countries. It is now commercially available. The dose recommended is a single administration of 20 IU per kg of body weight. The recommended procedure is to inject part of the dose around the wound and to administer the rest by IM in the gluteal region. This should be followed by a course of vaccine and additional booster doses of vaccine as indicated. It does not require any prior sensitivity testing.
Advice to patients
All patients undergoing anti–rabic treatment should be advised as follows: a) they should abstain from alcohol during and a month after completion of anti–rabic treatment since it may precipitate paralytic accidents or facilitate lighting up the infection. b) undue physical and mental strain and late nights should be avoided. c) cortico–steroids and other immunosuppressive agents should not be used d) rabies may develop following inadequate immunization.
Cell culture Vaccine
The vaccination schedule recommended consists of 6 doses (1 ml each) on days 0,3,7,14 and 30 and a booster dose on day 90. Injections are given intramuscularly (deltoid) and must not be given in to the buttock.
The major advantages of cell culture vaccines over conventional vaccines are their efficacy and a safety. Results indicated that 3 to 4 injections of cell culture vaccines produce antibody levels comparable with those induced by 10 injections of a nervous tissue vaccine. The disadvantages of cell culture vaccine is their cost. Vaccine vials should be stored between 40c and 80c after reconstitution and the total content should bee used as soon as possible.
Properly prepared cell culture vaccines have not been associated with serious adverse effects although a few vaccines may experience local redness, pain, headache and fever. But all symptoms are short–lived.
Pre Exposure Prophylaxis
Persons who run a high risk of repeated exposures such as laboratory staff working with rabies virus, veterinarians, animal handlers and wild life officers should bee protected by pre–exposure immunization. Such immunization should preferably consist of a dose of cell culture vaccine given either as 1 ml intramuscularly of 0.1 ml intradermally on days 0,7 and 28. Further booster injections should bee administered at intervals of 2 years as long as exposed person remains at risk.