This has a slightly different take on live vaccines. Who do you listen to?
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VaccinesTypes of Vaccines
Scientists take many approaches to designing vaccines against a microbe. These choices are typically based on fundamental information about the microbe, such as how it infects cells and how the immune system responds to it, as well as practical considerations, such as regions of the world where the vaccine would be used. The following are some of the options that researchers might pursue:
•Live, attenuated vaccines
•Inactivated vaccines
•Subunit vaccines
•Toxoid vaccines
•Conjugate vaccines
•DNA vaccines
•Recombinant vector vaccines
Live, Attenuated Vaccines
Live, attenuated vaccines contain a version of the living microbe that has been weakened in the lab so it can’t cause disease. Because a live, attenuated vaccine is the closest thing to a natural infection, these vaccines are good “teachers” of the immune system: They elicit strong cellular and antibody responses and often confer lifelong immunity with only one or two doses.
Despite the advantages of live, attenuated vaccines, there are some downsides. It is the nature of living things to change, or mutate, and the organisms used in live, attenuated vaccines are no different. The remote possibility exists that an attenuated microbe in the vaccine could revert to a virulent form and cause disease. Also, not everyone can safely receive live, attenuated vaccines. For their own protection, people who have damaged or weakened immune systems— because they’ve undergone chemotherapy or have HIV, for example—cannot be given live vaccines.