I just found this on
www.kennelcomfort.com:
TWO TYPES OF VACCINES. (And safe for puppies as well as pregnant bitches!)
There is the painlessly applied nasal vaccine which builds protection at the site of potential infection, starting within 48 hours. The "nose drop" vaccine is the one that we recommend for your dog. (Even though it is "painless" some dogs are resentful and will struggle.)
And, there is the injection by needle that works through the dog's lymph immune system. the needle injection vaccine requires two injections 3 to 4 weeks apart in order to build long-term protection against CC. Since some people don't go back for the booster 3-4 weeks after the initial vaccine, we do NOT recommend the injectable vaccine. Check with your veterinarian for his/her recommendations.