what are second generation vaccines

"This new generation of vaccines, a direct result of recent progress in genetic engineering, is characterised by the fact that it consists uniquely of antigens belonging to the virus capsid, i.e. all the proteins which form the viral coat, and yet provokes an immune response which is identical to that of traditional vaccines," explains Ignacio Casal, project coordinator. "Unlike the latter, the new vaccines are safer because the capsids do not contain any DNA - the basis for the virus's reproductive system - which eliminates the certainly minimal, but nevertheless real, risk of an unwanted multiplication of the virus. This technique also has another significant advantage: we can produce considerable quantities of antigens from in vitro cultures of insect cells in a very economical manner."