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.
The feline distemper vaccine is a common inoculation cats first get when they are between the ages of 9 and 11 weeks. Distemper vaccinations are recommended because of the communicability of the virus and the danger it poses other felines.