Which statement is true regarding live attenuated vaccines and recombinant vaccines?

Live attenuated vaccines and recombinant vaccines play important roles in immunization by provoking robust immune responses. The statement that they mimic natural infection and involve T cells in the immune response is accurate.

Live attenuated vaccines are designed to closely resemble the pathogen that causes the disease. By using a weakened form of the virus or bacteria, these vaccines elicit a strong immune response, which includes the activation of both B cells, leading to antibody production, as well as T cells, which play a crucial role in cellular immunity. This simulates a natural infection, allowing the immune system to build a memory against the pathogen, leading to long-lasting immunity.

In the case of recombinant vaccines, these utilize genetic engineering to create a vaccine that can also provoke a similar immune response. While they may not directly use the live pathogen, they often incorporate elements of it that stimulate T and B cell responses. Thus, they can lead to the production of specific antibodies and activation of T cells, aiding in the defense against future infections.

This comprehensive immune activation is significant in providing lasting protection and highlights the importance of T cells in the efficacy of these vaccines.