So a 74xx244 works at a commercial operating temperature, while a 54xx244 which is the same logic device [maybe the same pinout, and package] will continue to operate to the military operating temperature range [which is wider].
A distemper vaccine is more than a preventive against canine distemper virus. This vaccine, considered a core vaccine for all dogs in the United States, also protects against a host of other diseases you may not know your dog is susceptible to. These can include adenovirus, parvovirus, and others.
Feline distemper is a virus in cats and may be able to affect all members of the feline family. It is caused by a parvovirus and can be a life threatening disease. You need to have you cat vaccinated with it at the age of 12 weeks. Animal Wellpets Hospital can give you a better understanding of this condition.