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.
In cats, the suggested core vaccines are feline panleukopenia (distemper), feline viral rhinotracheitis, feline calicivirus, and rabies. The American Association of Feline Practitioners (AAFP) recommends vaccinating against feline panleukopenia (distemper), feline viral rhinotracheitis, and feline calicivirus every three years.