Answer:
The CDC also indicates that severe allergic reactions to vaccines can occur and that these reactions can sometimes be fatal.
Step-by-step explanation:
From the argument which states that vaccines can have dangerous side effects and the counterclaim that the CDC indicates that the vaccines are reviewed carefully before they are administered to people and the side effects are nowhere near as bad as the diseases they prevent, the best rebuttal would be to remind people that CDC indicates that some allergic reactions to the vaccines can sometimes to be fatal.
A rebuttal is the act of refuting something by making contrary argument or presenting contrary evidence.