The virus that is contagious between humans does not yet exist (or it may just have come into being inside a young person in China who contacted both vH7N9 and a humaninfluenza A virus to which they were not immune).
Since neither of the two children, a 10-year-old boy and a 9-year-old girl, had contact with pigs, it "increases the possibility that human-to-human transmission of this new influenzavirus has occurred, " according to a CDC report.
The new virus has genes from North American swine influenza, avian influenza, humaninfluenza and a form of swine influenza normally found in Asia and Europe, said Nancy Cox, chief of the CDC's Influenza Division.