[jp4m2]

These are findings from researchers.......

In one study of a cross section of different puppies the age at which they were able to respond to a vaccine and develop protection covered a wide period of time. At 6 wks. of age 25% of the puppies could be immunized. At 9 wks. of age, 40% of the puppies were able to respond to the vaccine. The number increased to 60% by 16 wks., and by 18 wks. of age, 95% of the puppies could be immunized.


The maternal antibodies in a puppy younger than 16 weeks may interfere with the immune response. At the ages of 14 to 16 weeks of age, PAMA (passively acquired maternal antibody) should be at a level that will not block active immunization in most puppies (>95%) when a reliable product is used. It should be noted that giving vaccine more frequently than every 2 weeks will cause interference between the two vaccines and neither can be expected to be effective. This includes giving vaccines for different infections.
Vaccines should be spaced 2-4 weeks apart. Although increasing the number of components in a vaccine may be more convenient for the practitioner or owner, the likelihood for adverse effects may increase. (American Animal Hospital Association)

"Dogs and cats immune systems mature fully at 6 months. If a modified live virus vaccine is given after 6 months of age, it produces immunity, which is good for the life of the pet (ie: canine distemper, parvo, feline distemper). If another MLV vaccine is given a year later, the antibodies from the first vaccine neutralize the antigens of the second vaccine and there is little or no effect. The titers are not “boosted” nor are more memory cells induced. "J Dodds, DVM