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.
There is a distemper vaccination shot; technically, this shot protects dogs against the parvovirus, which is a specific type of virus that causes the infection known as distemper. If you are considering acquiring a dog as a pet, you should familiarize yourself with this vaccination as soon as possible. While distemper is a deadly and very dangerous disease for pet dogs, it is not often a major concern for humans; humans can get the virus, but there are no effects.