Which of the following is specifically classified as a live vaccine?

The Measles, Mumps, and Rubella (MMR) vaccine is classified as a live vaccine because it contains live, attenuated (weakened) viruses that stimulate an immune response without causing the diseases themselves. Live vaccines work by providing a strong immune response that closely mimics natural infection, which helps the body to create effective long-lasting immunity.

In contrast, the Human papillomavirus vaccine (9vHPV) and the recombinant zoster vaccine (RZV) are considered non-live vaccines. The 9vHPV vaccine is a non-infectious, recombinant vaccine that helps prevent HPV-related cancers and diseases. The RZV is an inactivated vaccine specifically designed for the prevention of shingles. Similarly, DTaP or TDaP vaccines are inactivated vaccines that protect against diphtheria, tetanus, and pertussis.

Thus, among the provided options, only the MMR vaccine utilizes live, attenuated virus components, making it the correct choice in the context of live vaccines.