Both statements are correct regarding Recombinant Vector Vaccines. Genetic engineering is indeed applied to create these vaccines by manipulating the genetic material of pathogens to produce antigens safely, which in turn elicits an immune response in the host. Furthermore, both bacteria and viruses can serve as vectors to deliver these antigens effectively, enhancing the immune response without causing the disease itself. This biotechnological approach is significant in modern vaccine development as it allows for targeted and potent immunization strategies against various infectious diseases.