What are live vaccines?

What are live vaccines?

• A. Live, attenuated complete organisms derived from wild virus or bacteria.
• B. Killed organisms or portions thereof.
• C. Only recombinant subunit components.
• D. Synthetic peptide antigens.

Answer: (A)

Live vaccines use a living, yet weakened, version of the microbe. They contain a complete organism that has been attenuated from its wild-type form so it can replicate in the body without causing the disease in healthy individuals. Because this replication presents the immune system with the full set of antigens in their natural context, it tends to produce a strong and broad immune response, often with lasting protection after just a few doses. This is different from vaccines made with killed organisms or parts of organisms, which do not replicate and usually require more boosters to maintain immunity. It’s also distinct from vaccines that use only recombinant proteins or synthetic peptide fragments, which provide immunity without any live organism. Examples of live vaccines include those made from weakened measles, mumps, and rubella viruses, varicella (chickenpox), and oral polio vaccines. Live vaccines are generally not given to individuals with certain immune problems or to some pregnant people, due to the need for controlled replication to achieve immunity.

Live vaccines use a living, yet weakened, version of the microbe. They contain a complete organism that has been attenuated from its wild-type form so it can replicate in the body without causing the disease in healthy individuals. Because this replication presents the immune system with the full set of antigens in their natural context, it tends to produce a strong and broad immune response, often with lasting protection after just a few doses.

This is different from vaccines made with killed organisms or parts of organisms, which do not replicate and usually require more boosters to maintain immunity. It’s also distinct from vaccines that use only recombinant proteins or synthetic peptide fragments, which provide immunity without any live organism.

Examples of live vaccines include those made from weakened measles, mumps, and rubella viruses, varicella (chickenpox), and oral polio vaccines. Live vaccines are generally not given to individuals with certain immune problems or to some pregnant people, due to the need for controlled replication to achieve immunity.