H5N1, a subtype of the Influenzavirus, is a highly dangerous virus recognized for the severe pneumonia and high mortality rates observed in wild birds and poultry, commonly referred to as "bird flu". Despite the fact that H5N1 affects only birds, the virus has adapted and started affecting a wide variety of mammals, including dairy cows, minks, seals, and cats. In a few cases, the virus has occasionally resulted in severe human illness and death when people come into direct contact with animals, their bodily fluids, and the environment. Despite the fact that the spread of the virus from person to person has yet to be verified, the growing presence of the H5N1 virus in mammals and the possibility of it changing into a much worse form has prompted health experts around the world to consider the virus a significant human health pandemic threat.