An Essential Guide to your Puppies Vaccinations, How & Why we Vaccinate!
Until they are roughly six to eight weeks old, puppies are protected from certain diseases by antibodies in their mothers' milk, as long as they mothers have been immunized properly against those diseases and have sufficient antibodies to confer immunity. This passive immunity interferes with the ability to produce antibodies which is the response to vaccination. Therefore puppies are not vaccinated for the first time until they are at least six weeks old.
The serious of booster shots given to puppies contains antigens that have been derived ultimately from viruses or bacteria obtained from live animals. Typically, a six-week-old puppy is vaccinated against distemper, hepatitis, parainfluenza, parvovirus, and corona viruses. When those antigens begin circulating in the puppy's bloodstream, they are detected and seized upon by specialized cells that are part of the body's immune system. After a series of complex evolutions, the puppy's immune system produces cells that are able to detect and destroy the diseases represented by the antigens in the vaccine. Thus, if a dog vaccinated against distemper was later exposed to the virus, distemper antibodies would recognize and exterminate any free-ranging distemper virus particles at large in the bloodstream. And if the distemper invaders managed to infect some of the dog's cells, those infected cells would be recognized, destroyed, and down the door by other specialized systems in the immune system.
One vaccination, however, does not represent instant immunity on a puppy. It takes up to five to ten days before a puppy's immune system starts to forge a response to the challenge posed by antigens in a vaccine. That response is low grade and not entirely effective. What's more, one can never be certain how long a puppy's passive immunity will continue to compromise his ability to manufacture his own antibodies. For these reasons your veterinarian will revaccinate your puppy in three to four weeks, and again four weeks after the second vaccination. After that, dogs should receive booster shots once a year because antibodies decrease in number over time and the immune system needs to be stimulated to produce additional disease-fighting troops.