[schatzie]

I have read to begin giving the pups their vaccinations @ 6 to 7 weeks of age: Give first combination vaccine. (Distemper, Hepatitis, Parvovirus, Parainfluenza, Coronavirus)

The pups receive their Mama's immunity from her milk/colostrum the first days of life. This immunity wears off after several weeks but no way to exactly when. I read that if it wears off the puppy will be vulnerable; but if the vaccinations are given before it wears off they wont be effective and the pup is equally vulnerable. The series of vaccinations are given in order to catch the immune system at the earliest time the vaccinations will take affect.