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

RESUMO

Background. The prevention of rabies in Mexico continues to be an importan goal for the health sector. Although the prevalence of this disease continues to fall, between 1990 and 1995 a total of 238 cases were registred (an average of 40 cases annually), with a mean annual incidence of 0.04 cases per 100,000 inhabitants and a mortality of almost 100 percent, so that it is important to rely on highly effective vaccines with few side effects. The objective 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 brain tissues of suckling mice, and to find the role antirabies hyperimmune gamma globulin plays in the concentration of post-vaccination antibody concentrations. 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-dose intramuscular schedule of the human diploid cell rabies vaccine. Subjects were followed daily, and local and systemic signs and symptoms were recorded. Two blood samples (at baseline-and at the end of 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 adenopathy were fewer than those reported in the literature for the Fuenzalida vaccine (p < 0.05), and of induration and local pain (p <0.05) in relation to 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 good 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 and opportune level of protection provided by prophylactic vaccine to patients with exposure to rabies