Sample Response: Scientists are creating vaccinations that prevent people from getting bird flu. If the virus mutates, a new vaccine needs to be made. The vaccine needs to be tested, which can be dangerous. It also takes a long time for scientists to know whether the vaccine works. Which ideas did you include in your answer? Check all that apply. Scientists are creating vaccines. Viruses that mutate need new vaccines. Vaccines take a long time to make. Vaccines need to be tested.