Observation of the effects of inoculation with a domestic lyophilized non-adjuvanted rabies vaccine derived from Vero cells

Objective To observe the immunogenicity of and reaction to a low-dose intradermal injection of a lyophilized rabies vaccine derived from Vero cells without adjuvant for a pre-exposure group.Methods In accordance with informed consent,a population in close contact with dogs was selected and 244 individuals with class I exposure to rabies received pre-exposure immunization.In a randomized,single-blind manner,subjects were divided into two groups: group A,an intradermal injection(ID) group of 122 individuals receiving an intradermal injection of 0.1ml vaccine at each site on D 0,7,and 28,and group B,an intramuscular injection(IM) group of 122 individuals receiving a full-volume(0.5 ml) PVRV injection in the deltoid on D 0,7,and 28.Local and systemic responses to the vaccine were observed with the different routes of injection.An indirect sandwich ELISA assay was used to analyze antibody levels.Results For the ID group,the incidence rates for local redness and swelling,induration,pain,and itching were 1.09%,0.27%,0.27%,and 10.66%,respectively.For the IM group,the incidence rates were 0.82%,0.27%,1.64%,and 0.82%,respectively.For the ID group,the incidence rates for systemic reactions in the form of fever,rash,headaches,and fatigue and weakness were 0.27%,0.27%,0.55%,and 0.82%,respectively,while similar incidence rates for the IM group were 0.55%,0.27%,0.55%,and 0.82%,respectively.Adverse effects often occurred following the 1st and 2nd injection.The respective seroconversion rates for the ID injection group and IM group were 94.21% and 95.08% after D 42 of immunization,and the difference in seroconversion rates was not statistically significant(P0.05).Conclusion The domestic lyophilized rabies vaccine derived from Vero cells resulted in mild adverse reactions and had good immunogenicity.A domestic lyophilized rabies vaccine derived from Vero cells can,when given in low-dose intradermal injections without adjuvant,be used to vaccinate a pre-exposure group.