which of the animal is a carrier of h1n1
Swine influenza The H1N1 form of swine flu is one of the descendants of the strain that caused the 1918 flu pandemic.[64][65] As well as persisting in pigs, the descendants of the 1918 virus have also circulated in humans through the 20th century, contributing to the normal seasonal epidemics of influenza.[65] However, direct transmission from pigs to humans is rare, with only 12 recorded cases in the U.S. since 2005.[66] Nevertheless, the retention of influenza strains in pigs after these strains have disappeared from the human population might make pigs a reservoir where influenza viruses could persist, later emerging to reinfect humans once human immunity to these strains has waned.[67]