[Validation of an ELISA assay for the quantification of antibodies against Haemophilus influenzae type b capsular polysaccharide].

The validation study of an ELISA assay -internationally accepted for this purpose- was conducted aimed at having a method for the quantification of antibodies against Haemophilus influenzae type b (Hib) capsular polysaccharide in the clinical trials used to prove the immunogenicity of a new conjugated vaccine composed of a synthetic antigen. The validation was carried out in the National Haemophilus Reference Laboratory, in "Pedro Kouri" Institute of Tropical Medicine, Havana, Cuba. A protocol was designed, in which the determination of accuracy, exactness, linearity and limit of the detection of the assay were considered. The Hib Batch 1983 international reference serum was used in the preparation of the standard pattern curve. Dispersion indexes lower than 10 and 20% were observed for the repeatability and reproducibility of the system, respectively. The limit of detection was 3.6 ng/m and the recovery and linearity trials showed the high accuracy of the method. It was concluded that during the clinical evaluation of the candidate vaccine obtained by chemical synthesis, the quantification of antibodies against Hib capsular polysaccharide may be faced with an appropriate precision and exactness by using the proposed method.