Recombinant vaccine is better than conventional …

Even though vaccines based on recombinant proteins offer several advantages when compared with traditional vaccines, such as safety and production cost, most of them present weak or poor immunogenicity when given alone, and thereby require the use of adjuvants to elicit a protective and long-lasting immune response. The successful use of recombinant proteins as vaccines, including hepatitis B and, more recently, HPV, was possible due to the use of aluminium salt as adjuvant. Therefore, the investigation of new adjuvants is an extremely important field in vaccinology. The main difficulties for the development of new adjuvants involve understanding their molecular complexity and the mechanisms by which they operate to stimulate or induce the immune response. For example, the mechanism of action of the aluminum salts, which are the most commonly used adjuvants in human and animal vaccines worldwide, remains unknown. However, Richard Flavell's group recently suggested that they would activate an intracellular innate immune response system called Nalp3 inflammosome. An alternative path for antigen presentation has been the use of live vectors, such as bacteria and viruses, in which their natural adjuvant properties are explored. Formulation and safety, among other concerns, are also important aspects to be considered.