www.naturalrearing.com/coda/l_vaccinations.htmlexcerpt from this great article:
well worth reading just this portion if not all!
Dr. Ronald D. Schultz, Ph.D., D.V.M.
For those of you not familiar with Dr. Schultz I should mention that he is recognized as a pioneer in clinical immunology and vaccinology. As Professor and Chair of Department of Pathobiological Sciences at the School of Veterinary Medicine, University of Wisconsin-Madison his work is well known in both the allopathic and holistic veterinarian communities.
Wow! If you’re looking for someone with ‘authority’ to refer to the nonsense of annual boosters, get your ‘doubting Thomas’ to call on Dr. Schultz. Not only does he confirm that their is no science for this practice, he also warned of the possibility for law suits, if a Vet continues to recommend them. He pointed out that immunity to viruses persists for years or for the life of the animal.
He eloquently covered the many factors that can effect the immune response to a vaccine. The blocking effect of colostral antibody from the mother, the nature of the vaccine, the route of vaccination, the age of the animal, its general nutritional condition, concurrent infections, drug treatments—all may have an influence on the success of an immunization program.
Maternal antibody interference is the most common cause of vaccine failure. The fetus develops a functional immune system at 45 to 50 days into gestation. The level of maternal immunity at the time of birth will vary considerably, even among litter mates, but in general will stay high for 10 days to 2 weeks. A major cause for reduced immune response during the first week, is ‘hypothermia’. It is important that a temperature of 99° F be maintained during this critical time frame!
Between 2 week and 4 weeks, while still nursing, the immune system of the neonate grows and begins to take on its own duties. At the time of weaning, the immune system suffers from a decrease in nutrients and can be significantly lowered from a lack of Vitamin E and selenium. This is particularly true with ‘canned’ foods so it is better to start with ‘dry’ food. At 8 to 10 weeks, the neonate is closer to having an adult immune system. (Ed. Note: raw fresh food is of course best for weaning).
Because maternal antibodies can persist far longer then previously thought possible, Dr. Shultz strongly recommends that the last vaccination take place at 22 weeks for a puppy and 16 weeks for a kitten. There is new information that indicates that as many as 20% of dogs at 18 weeks have enough maternal antibodies to prevent successful parvo immunization. (Note: previously it was recommended that the last immunization in the series occur at 12 to 16 weeks of age).
Make sure your vet is aware of these new findings!!
Here’s a real kicker. A major problem, especially for parvo, is that the virus is able to infect an animal with levels of maternal antibody even though the antibodies prevent active immunization!! There is generally a 2 to 5 week "window of vulnerability" and in heavy parvo environments, as much as a 10 week "window", when an animal can be infected with the virus but cannot be successfully immunized!!
On the question of modified live versus ‘killed’ vaccines, Dr. Schultz is of the opinion that both have a place in the immunization schedule. Currently, there are no absolute answers.
He felt that because MLV vaccines replicate in the host, they more closely resemble virulent viral infections and generally produce a stronger and more durable protective immune response than killed vaccines. This "better" immune response has a cost: a decrease in vaccine safety. Certain modified live vaccines can induce immunosuppression, may shed into the environment, and may revert to virulence or cause vaccine-induced disease.
Killed vaccines on the other hand, are safer but require a large antigenic dose, multiple immunizations and often the use of adjuvants that can cause an increase in systemic vaccine reactions. Also, killed vaccines generally produce weaker immune responses with a shorter duration than the modified live vaccines. Sometimes the immune responses they produce lead to immunopathological disease at time of infection rather than providing protection. With respect to dosages, he pointed out that at the cellular level, the same number of receptor cell sites exist regardless of the size of the body, thus there is no justification for adjusting dosage quantities for different breeds of animals. (see Jean Dodds segment for a different opinion).
He does favor MLV for Parvo in high risk areas. He feels that ‘killed’ vaccine is too slow in providing immunization due to the need for multiple shots. He pointed out that the Parvo vaccine is expensive to produce, so the companies use as little as possible in each dose.
As modified live vaccines replicate in the body a "mini" dose is still effective. With killed vaccine, how much is enough? His research into the effectiveness of vaccines, has led to the manufacturers revising several of their formulas. He cautioned the audience not to dilute or split the dosage when administering any ‘killed’ vaccine.
With respect to nutritional deficiencies, someone in the audience asked about "Blue-Green Algae". Dr. Schultz commented that in his experience, their can be a danger of nutrient toxicosis. He knows of ponds in his area, with blue-green algae, where dogs that have jumped into a pond have suffered paralyses and in some cases have died.
In general, he felt that modified live vaccines when given to animals in good general health have no clinical indication of immunosuppression.
(Ed note: Dr. Dodds points out that the MLV trials by Dr. Schultz have only been tested on purposely bred Beagles and not breeds that are genetic and familial susceptible to suppression. She advocates "killed" vaccines.)
I am handicapped apparently! 
but we are fun to watch!