Improved serological response to human diploid cell rabies vaccine when given simultaneously with antirabies hyperimmune globulin

Background. The prevention of rabies in Mexico continues to be an important goal for the health sector, Although the prevalence of this disease contin ues to fail, between 1990 surd 1995 a total of 238 cases were registered (a n average of 40 cases annually), with a mean annual incidence of 0.04 cases per 100,000 inhabitants and a mortality of almost 100%, so that it is impo rtant to rely on highly effective vaccines with few side effects. The objec tive of this work was to evaluate seroconversion and tolerance to the human diploid cell antirabies vaccine administered to individuals with a history of exposure to rabies, to compare these results with those reported in the literature for the Fuenzalida vaccine, a rabies vaccine produced in the br ain tissue of suckling mice, and to find tf-le role antirabies hyperimmune gamma globulin plays in the concentration of post-vaccination antibody conc entrations. Methods. An analytical transverse study was carried out in 40 children and adults with a history of rabies exposure who were given a complete, five-do se intramuscular schedule of the human diploid cell rabies vaccine. Subject s were followed daily, and local and systemic signs and symptoms were recor ded. Two blood samples (at baseline and at the end of the vaccination sched ule) were taken and antibody titers against rabies glycoprotein, using the ELISA technique, were measured, Results. Adverse side effects produced by the human diploid cell antirabies vaccine, such as frequency of pain, erythema, itching, and regional adenop athy were fewer than those reported in the literature for the Fuenzalida va ccine (p < 0.05), and of induration and local pain (p < 0.05) in relation t o the latter vaccine. All patients seroconverted, producing geometric mean antibody titers of 6.22 IU/mL, an arithmetic mean titer of 9.66 IU/mL with a SD of 9.1 IU/mL, The level of tolerance to the diploid cell vaccine was g ood and its adverse effects were minimal and fewer than those reported for the Fuenzalida rabies vaccine. Patients receiving the diploid cell vaccine plus antirabies hyperimmune gamma globulin developed higher antibody titers (measured by ELISA test) at the end of the vaccination schedule than those only receiving the vaccine. Conclusions. These results are important in order to achieve an adequate an d opportune level of protection provided by prophylactic vaccines to patien ts with exposure to rabies. (C) 1999 IMSS. Published by Elsevier Science In c.