Flu season typically begins in the fall months with cases of influenza A strain, but unexpectedly the B strain has appeared more dominant during the early months of this year’s flu season.
The B strain is less complicated than the A strain and doesn’t change, or mutate, as much, the CDC says. It’s divided into two families, Yamagata and Victoria, with the large majority of American cases being Victoria. Type B flu only affects humans and doesn’t cause pandemics, although it is seen as more dangerous to young children.
Type A has many variations, mutates all the time, and is responsible for flu pandemics. Type A can also infect animals. It’s usually passed from human to human through airborne germs, but animals can pass the illness to humans, with wild birds commonly acting as the hosts for this virus.