A parent says, I have heard that some of the vaccines contain the microbe that causes the actual ...

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Rationale 1: These are called attenuated vaccines. The microbes are weakened.
Rationale 2: These vaccines can cause disease in those who are immunocompromised.
Rationale 3: MMR is an example of such a vaccine.
Rationale 4: Not all vaccines are made with killed microbes.
Rationale 5: Toxoid vaccines contain bacterial toxins.

Global Rationale: These are called attenuated vaccines. The microbes are weakened. MMR is an example of such a vaccine. These vaccines can cause disease in those who are immunocompromised. Not all vaccines are made with killed microbes. Toxoid vaccines contain bacterial toxins.