Comparative evaluation of immunogenicity, reactogenecity and safety of purified chick embryo cell rabies vaccine and neural tissue rabies vaccine.

OBJECTIVES 1. To compare the protective antibody titres on day 14, 30 and 90 after giving intramuscular (IM) injections of PCECV and subcutaneous injections of Nervous Tissue Vaccine. 2. To compare the immunogenicity and safety of PCECV and NTV. METHODS AND MATERIALS The study enrolled cases in three groups. Group 'C' or control group: (n = 38) : This group comprised of 38 normal healthy volunteers without dog-bite. Group 'A' (n = 102): This group included cases of dog-bite fulfilling inclusion/exclusion criteria. Each one of Group A and C were given PCECV as post exposure treatment (PET) on day 0-3-7-14-30 and 90. Group 'B' (n = 50): This group included 50 cases of dog-bite who received NTV. The rabies virus neutralizing antibody titres were estimated by RFFIT (Rapid Fluorescent Focus Inhibition Test) on day 0, 14, 30 and 90 days. 45 recipients of PCECV were re-tested for persistence of Protective Antibodies at the end of 1 year. RESULTS Of these 37, 91 and 45 cases were evaluable in Groups C, A and B respectively. The antibody titres in Groups A, B, C were 13.4, 3.2, 22.8 IU/ml respectively; the protective titre being 0.5 IU/ml.5% PCECV recepients had delayed response on day 30.14% of NTV recepients did not seroconvert. CONCLUSIONS The Immunogenicity, Reactogenicity and safety of PCECV is well established. 5% of PCECV receipients showed a delayed sero conversion. 14% of NTV receipients did not sero convert at all. Therefore it is desirable to estimate antibody titres on day 14 after vaccination. If difficult, then all the cases of animal bite must receive passive immunization with rabies immunoglobulins.