Francis was the first person to isolate influenza virus in the United States, and in 1940 showed that there are other strains of influenza, and took part in the development of influenza vaccines.
弗兰西斯是第一位在美国分离出流感病毒的科学家，在1940年发现了另一种的流感病毒株，并参与了流感疫苗的研制。