When considering at what age a puppy should begin receiving its core vaccines, consider the information from the American Animal Hospital Association stating that the maternal antibodies in a puppy younger than 16 weeks may interfer with the immune response. Bear in mind that there are risks associated with vaccinating as well as risks associated with not vaccinating. Making an informed decision is important. Also, be aware that giving combo vaccines (multi-valent) and/or several shots at once increases the risk of adverse reactions as well as the risk that the vaccines will interfere with each other, resulting in neutralization or negation.
In the August 2008 issue of
The Whole Dog Journal, Dr. Ronald Schultz reports in an article entitled,
Vaccinations 101, by Lisa Rodier,
"Research shows that less than 50 percent of puppies will respond at six weeks; 75 percent at nine weeks; 90 percent at 12 weeks; and by 14 to16 weeks, close to 100 percent will respond. "
In an August 1, 2008 article in
DVM360 entitled
Vaccination: An Overview,
Vaccination: An overview (Proceedings) - Veterinary Healthcare Dr. Melissa Kennedy states:
Vaccination of the young begins at 6-8 weeks of age. Multiple boosters are given because maternal immunity interferes with vaccinal response. Because one doesn't know the level in each animal for each pathogen at each time point (and it is not feasible nor cost-effective to measure this), repeated boosters are given until the point when maternal immunity has likely decreased sufficiently to allow induction of immunity, usually at 16-18 weeks of age.
On Page 16 of the of the
American Animal Hospital Association's 2003 Canine Vaccine Guidelines, it reports that:
When vaccinating an animal, the age of the animal, the animal's immune status, and interference by maternal antibodies in the development of immunity must be considered. Research has demonstrated that the presence of passively acquired maternal antibodies significantly interferes with the immune response to many canine vaccines, including CPV [parvo], CDV [distemper], CAV-2 [hepatitis] and rabies vaccines."
They further state on Page 17 that:
"Multiple vaccinations with MLV vaccines are required at various ages only to ensure that one dose of the vaccine reaches the puppy's immune system without interference from passively acquired antibody. Two or more doses of killed vaccines (except rabies) and vectored vaccines are often required to induce an immune response, and both doses should be given at a time when the passively acquired antibody can no longer interfere. Thus, when puppies are first vaccinated at 16 weeks (or more) of age (an age when passively acquired antibodies generally don't cause interference), one does of an MLV vaccine, or two doses of a killed vaccine, are adequate to stimulate an immune response."
The AAHA Canine Vaccine Guidelines also declare on Page 17 that: "
If a pup fails to respond, primarily due to interference by passively acquired maternal antibody, it is necessary to revaccinate at a later time to ensure adequate immunity."
On Page 13 of the
2006 American Animal Hospital Association's Canine Vaccine Guidelines, it lists as the most common reason for vaccination failure is "
the puppy has a sufficient amount of passively acquired maternal antibody (PAMA) to block the vaccine......" They elaborate by reporting that at the ages of 14 to 16 weeks of age, "
PAMA should be at a level that will not block active immunization in most puppies (>95%) when a reliable product is used." Vaccine Options & Prevention, MATERNAL ANTIBODY: OUR BIGGEST OBSTACLE Vaccination Options/Prevention
Puppies that were born first or were more aggressive at nursing on the first day, will get more maternal antibody than their littermates.
Mother dogs vaccinated at approximately the time of breeding will have the highest antibody levels to pass on to their puppies.
*** REMEMBER, the more maternal antibody a puppy has,
the less likely a vaccine is to work.
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.
It is commonly held that puppies need a certain number of vaccines for protection to be achieved (usually either 3 or 4 is the “magic” number). The number of vaccines given has nothing to do with protection. In order for protection to be achieved, vaccine must be given when it can penetrate maternal antibody. Combination Vaccines, Multiple Shots--on Page 16 of the
2003 AAHA Guidelines under
Immunological Factors Determining Vaccine Safety, it states that:
"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. Also, interference can occur among the components. Care must be taken not to administer a product containing too many vaccines simultaneously if adverse events are to be avoided and optimal immune responses are sought. "
The World Small Animal Veterinary Association's 2007 Vaccination Guidelines state on Page 3 that:
In situations where, for example, a decision must be made that an individual pet may have to receive only a single core vaccination during its lifetime, the VGG [Vaccination Guidelines Group] would emphasise that this should optimally be given at a time when that animal is most capable of responding immunologically, i.e., at the age of 16 weeks or greater." Continued Below