When the h1n1 vaccine (swine flu
) was created in 2009, it was not included as a strain in the seasonal flu vaccine.
So you could get it separately. However, every year since, that strain has been a part of the seasonal vaccine and is not available by itself. There are many strains of flu and each year the cdc picks 2 type a & 1 type b strain that were the most prevalent from the prior season.