For the first time, it is reported in our country the successful expression of a simple chain Fv type (scFv) antibody fragment, specific for the surface antigen of hepatitis B virus (HbsAg), in transgenic tobacco plants, to be used in the purification process of the recombinant HbsAg taken place in the Center for Biotechnology and Genetic Engineering (CIGB) , base of the recombinant vaccine. The scFv fragment originally produced in E. Coli, has already shown the potentiality to substitute anti-HbsAg murine monoclonal antibody that is usually used in the production of this vaccine.

These results, which have been published in 4 international magazines, cleared the way for an evaluation of the economy of this production's ascension, executed at this time.

This work represents, from the scientific and technical point of view, the first example of a transgenic plant developed as biological bio-reactor in Cuba, and regarding international literature, it is the first one in which an antibody fragment is sent to the secretory cellular pathway through a peptide, signal of the sporamina from sweet potato.

From the practical point of view , the developed knowledge allows having an alternative source, with a great potential, for the production of antibodies and its fragments on a large scale.

The achieved results have immediately attracted the attention of several groups in the country, with which joint projects have been started for the productive ascencion of therapeutic antibodies for human use.