Which combination of vaccines are considered live vaccines?

Live vaccines are those that contain a weakened (attenuated) form of the virus or bacterium that causes disease. This allows the immune system to recognize and respond effectively without causing the disease itself.

In this context, the combination of MMRV (measles, mumps, rubella, and varicella) and Varicella (chickenpox) consists of live attenuated vaccines. Both MMRV and Varicella vaccines use live, weakened viruses, which stimulate a robust immune response by simulating a natural infection, providing long-lasting immunity.

Other combinations may include vaccines, but they do not feature live attenuated components. For instance, Hepatitis A and DTaP are inactivated vaccines, meaning they do not contain live pathogens. Similarly, Hib (Haemophilus influenzae type b) and PCV13 (pneumococcal conjugate vaccine) are also not live vaccines, as they use inactivated components or polysaccharides to elicit an immune response.

Recognizing the difference between live and inactivated vaccines is crucial for immunization practices, as it affects how and when vaccines can be administered, as well as understanding potential interactions with other medical treatments.