Strategies of constructing recombinant vaccines.

Vaccines are the most effective prophylactic tool in veterinary medicine. Despite the great success of many vaccines used currently, there is still a constant need for their improvement. An ideal vaccine should contain a variety of immunogens, be safe and efficacious and induce broad humoral and cell-mediated immunity with one or, at most, two administrations given orally rather than by injection, and should be inexpensive. Traditional approaches include attenuated live vaccines, inactivated vaccines and subunit vaccines. Recently, scientific advances in molecular biology, immunology and bioinformatics, as well as the growing number of sequenced genomes of pathogens, have led to significant progress in respect to understanding virulence mechanisms at the molecular level. Genetic engineering has been applied to obtain recombinant bacterial and viral genomes in order to produce a modified and safe product useful in vaccine development. This article presents the progress and novel strategies used in creating new generation vaccines. It focuses on methods of searching for vaccine candidates to construction of vaccines based on recombinant DNA or proteins.