Explanation:
Vaccines for both measles and flu already exist, however the flu vaccine must be updated because of the virus's ability to change and adapt in order to invade cells in the human body. The goal of researchers was to find genes in each virus that cannot survive changes.
By comparing two similar viruses which attack the body in similar ways through the lungs, researchers confirmed that the measles virus is much less open to evolutionary change by using an experimental technique called insertional mutagenesis to change the genes of each virus.
