Explanation:

Genetic engineering is applied in the development of these vaccines: True. Recombinant vector vaccines use another virus (or bacterium) as a delivery system. The genetic material from the pathogen of interest is inserted into the genetic material of the vector. This allows the vector to produce the antigens of the pathogen without causing disease. This process involves genetic engineering techniques.

Bacteria and viruses are used as vectors: True. In the realm of vaccine development, vectors can indeed be bacteria or viruses that have been modified so they cannot cause disease in humans. The main objective is to use them as delivery systems to introduce the genetic material of a pathogen into the human body, triggering an immune response without causing disease.

Given the above explanations, both statements are correct.