I think the first thing of importance to learn is that vaccines do nothing more then introduce imitation disease into a pup's body. If the pup's immune system is working correctly it will think that the body is under attack and will produce antibodies against the disease. Puppies have immature immune systems and it is common practice for Veterinarians and Breeders to give 5 vaccines at one time to puppies as young as 6 weeks old.
This overloads and confuses the puppies' immune system causing it to become suppressed and no antibodies are formed to protect against disease. Statistics show that 80% or more of puppies under 8 weeks do not develop significant titer levels to Distemper when given a Distemper vaccines.Yet wait until a puppy is over 10 weeks and old and you have 80% who will have a healthy immune response. Unfortunately if a puppy is bombarded with several vaccine at once under 8 weeks then by 10 weeks of age the immune system is in poor shape. So early vaccine with multiple vaccines can ruin proper vaccination response weeks later. We give a single Parvo vaccine under 9 weeks and give multiple vaccines after a puppy is over 10 weeks
If you give a dog 5 different vaccines at one time the dog's immune system thinks it has been hit with 5 diseases.
How often in nature are dogs struck with 5 diseases at one time? NEVER. A dog will contact ONE disease at a time and the immune system will focus on that one disease and build immunity by producing antibodies to that disease.
Even with all the new warnings on vaccine safety, plenty of Veterinarians and most breeders continue to give 6 to 8 week old baby puppies polyvent vaccines with as many as 5, 6, 7 or even 8 vaccines given at the same time.
A very young puppy's immature immune system is suppose to know what to do with so many diseases ?
IT IS THE PUP'S IMMUNE SYSTEM THAT PRODUCES THE IMMUNITY TO DISEASE.
RUIN THE IMMUNE SYSTEM AND VACCINES ARE WORTHLESS.
When a young puppy is hit with 5 or more different diseases (vaccines) at the same time, the immature immune system might be able to focus on ONE of the vaccines, and built up some titer level to that one disease, so a puppy might survive Parvo and die of Distemper.
Another reason vaccines do not work in very young puppies is because most very young puppies up to 9 weeks old still have maternal antibodies circulating in their bloodstream and vaccines can be inactivated by these maternal antibodies.
In review:
Vaccines do NOT produce protection from disease. They only simulate canine disease.
Too many vaccines at one time in a young puppy confuses and suppresses the immune system
Vaccines are only effective with a healthy immune system. Vaccines in themselves do not produce any protection.
The IMMUNE SYSTEM must identify the diseases (vaccines) and create antibodies of protection.
Too many vaccines at one time in an adult dog is dangerous too. I advise to never permit your Veterinarian to give the Rabies right along with your pets yearly or bi-yearly booster. Also if your Veterinarian gives your pet a CORONA vaccine ask him to explain why he would do this since Corona is a puppy illness and does not cause illness in adult dogs.