In this work, there are presented for the first time direct evidences that demonstrate the ultraestructural similarity of AgsHB (superficial Antigen of Hepatitis B) produced in Pichia pastoris transformed yeast, and the one present in serum and hepatocytes of animals and humans infected with HBV (Hepatitis B virus).

It is reported the existence of crystalloid bodies in the yeasts that express AgcHC (Core Antigen of Hepatitis C), as well as SVP (Similar Particles to Virus), aggregates of SVP and tubular structures, which was never described before in a recombinant yeast. The existence of crystalloid bodies was only informed for cell lines of transfected mammals with recombinant antigens of HCV.

It is described a high correspondence in the expression and assembling of the antigens of both virus in hepatocytes and in P. pastoris yeast, and biological models are suggested for the SVP synthesis and assembling processes in hepatocytes infected with HBV and HCV, and in the yeast. These models are very useful in the development of vaccinal preparations for HBV and HCV. It is also presented an analytic comparison of different commercial vaccines for Hepatitis B, showing a bigger homogeneity for the Cuban vaccine. Five publications are presented in prestigious magazines and a patent is granted in Cuba.