VACCINATIONS AND IMMUNITY IN PUPPIES
by Jessica Strauss

Puppies are born with immature immune systems, which could leave them wide open for infection. Luckily, Mother Nature has a built in system for the puppy's protection, called passive immunity, which comes from the puppy's mother, during nursing . The mother produces a special milk in the first 24-48 hours following whelping, called colostrum, which contains antibodies the mother herself carries in her own immune system. This is why the mother's vaccination history and her health status, are so important to the newborn puppies. As the puppies ingest the milk those first 2 days of their lives, they are acquiring their mothers immunity to a host of different diseases in which she has either been exposed to or vaccinated against. This occurs in a process called pinocytosis, and only occurs until the puppies intestines complete "gut closure" at around 1-2 days old, and can no longer absorb those antibodies in the colostrum, from their mother. Two myths involving maternal antibodies are the belief that as long as the puppy is nursing, it is gaining more protection, and that by allowing an older puppy to nurse on a new mother immediately after she gives birth, she will give them another dose of antibodies. Unfortunately neither works.

The duration of the maternal antibodies provided the puppies, depends on several different factors, which include the birth order of the puppy, how well the puppy nursed those first two days of life, and the mothers vaccination status also plays a part in the amount of maternal antibody passed to the puppies. Not all puppies in a litter will get the same amount of immunity. The mothers antibodies to different diseases wear off at different times too. The difficult question is at what time frame does the mothers immunity wear off and leave the puppy vulnerable. It varies from disease to disease and even from puppy to puppy. After a puppy is born, maternal antibody levels drop by half, approximately every 9-10 days. By the time the puppies are 16 to 20 weeks of age, the mothers immunity has completely worn off. During the time the mothers immunity is active in the puppies systems, any vaccines given, will be killed off by her immunity. Mother dogs who are vaccinated just prior to breeding, will have the highest level of antibodies to pass on to their puppies.

There is a period of time, called the "Window of Vulnerability", lasting about a week, lying sometime between the ages of 8 weeks and 20 weeks, in which the puppy will have not enough antibody protection left over from the mother, but too much maternal antibody to allow the puppy to respond to vaccination. This window is when even the most well cared for puppies get infected with parvovirus, and also the time in which we see unvaccinated puppies who are infected with Parvovirus. This is why vaccines are given at 2-4 week intervals from the time the puppy is 6-8 weeks old, until it has reached 16-20 weeks old, in an attempt to gain protection as early as possible, and catch that period of time in which maternal antibody has worn off, and the vaccine is accepted. Giving vaccine more frequently than every 2 weeks will cause interference between the two vaccines received, and neither will be effective. Another thing to consider, is that vaccines do not "take effect" immediately. When given, the antigens must be identified, responded to, and remembered by the immune system. Disease protection does not begin until at least five days, and as long as two weeks following vaccination. Modified live vaccines and intranasal vaccines provide the speediest protection.

It is a myth that puppies need a certain number of vaccines for protection to occur, with 3 or 4 being the “magic” number. The number of vaccines given has nothing to do with protection! In order for proper protection, the vaccine must be given when it can penetrate maternal antibody. Killed vaccine is the least effective at penetrating maternal antibody, and it should be recognized that some puppies, especially those of well-vaccinated mothers, must be vaccinated out to 20 weeks, unless a “high titer” vaccine is used. Maternal antibody is more likely to interfere with the parvo vaccine than any other viral or bacterial vaccine the puppy may receive.

What is a High Titer-Low passage Vaccine? The High Titer-Low Passage Parvo Vaccine is a Modified Live vaccine that has a higher number of virus particles (high titer) which are less attenuated (weakened) than in the standard vaccines. The benefit, is the vaccine's ability to penetrate maternal antibody and produce strong immunity in puppies at a younger age (around 12 weeks) than the regular parvo vaccine (16 to 20 weeks). Keep in mind that greater efficacy can mean loss of some safety factors. Many vaccine manufacturers are using the high titer parvo vaccine now. Of the vaccine's I have researched for my own adult dogs and puppies, The Vanguard series, manufactured by Pfizer, is the one we use and trust.

When the puppy is vaccinated, maternal antibody binds to the virus in the vaccine. If a high titer vaccine is used, there is still virus left over after all the maternal antibody has binded to part of it, which then can stimulate the puppy’s own immune system. High titer vaccines are considered state of the art.

Each Breeder and pet owner should become informed and determine what vaccine protocol is right for their pet. Remember, there is no "right" answer. In the 90's, Pfizer conducted a survey of Veterinary practices across the United States, and found there to be 1701 different vaccination protocols. Currently, the most common protocol for vaccinating puppies is the 2006 AAHA Canine Vaccination Guidelines, found [here].

There are three types of vaccine. Killed virus vaccine, Modified live vaccine, and Recombinant vaccine. Killed vaccine is not recommended in puppies because it does not provide the necessary immune response. Killed virus is most likely to cause adverse reactions because of adjuvants added to maximize effectiveness. Modified Live vaccine produce a stronger immune response, by behaving more like the actual virus. Virulence has to be reduced so as not to actually cause the disease it it meant to prevent. One way this is done is by making the virus dependant on a growth medium not found in the body, so that when they are introduced into the body, they produce the intended immune response and quickly die off. The newest class of vaccine is the Recombinants. There are 4 types of recombinant vaccine's. Simply put, the recombinants have an altered gene or part of the gene of a virus. Recombinants are both safe and very effective, and are the newest technology in vaccinations.

Now, to discuss is where to buy vaccine. Vaccines should be fresh, and shipped with ice packs in a refrigerated type carton. It is also recommend that vaccine is shipped by Next Day or Second Day Air service to ensure continued refrigeration and potency upon arrival. I currently buy my vaccine directly from my Veterinarian. There are probably a number of reliable places, on-line, in which to buy vaccine, but here are three links to companies I have used in the past and find trustworthy.

• Drs Foster and Smith: http://www.drsfostersmith.com/general.cfm?gid=1037&c=3307
• Revival Animal Health: http://www.revivalanimal.com/dog-supplies/dog-vaccines.htm
• KV Vet Supply: http://www.kvsupply.com

There are a number of things we can do, as Breeders, to keep our puppies safe and healthy while in our care. It has always been of concern to me, to allow people into my home, to see the puppies, because I don't know what pathogens they might be carrying in with them. Here are some suggestions for reducing the risk to the infant puppies.

• Bleach Foot Bath: Using a large pan, or cat litter box, place a full sized folded towel on the bottom of the pan. Fill pan to cover the towel with a solution of 1:32 solution of Bleach and Water. (1:32 is = to 4oz. per Gallon). Each visitor must step into the solution, covering the entire surface of the tread of their shoes. A hard bristled brush should also be used to remove any debris from the shoes. This solution must be changed frequently, because any organic material will deactivate the bleach.
• Potassium Peroxymonosulfate Foot Bath: This is an alternative to Bleach Foot Baths. Potassium Peroxymonosulfate is used frequently in Shelter Medicine, under the names Virkon-S and Trifectant. This chemical is used is other applications, such as "shocking" a swimming pool. The solution for a Foot Bath is 1.3 ounces to 1 gallon water. This method is reliable, as it retains more disinfectant activity in the presence of organic material.
• Use of hospital gowns/Booties: It is a good idea to purchase a box of disposable hospital gowns and booties, and have visitors wear these items while handling the puppies. They should also thoroughly wash hands, or if there is a concern, wear disposable gloves as well.

Some other concerns we should have, as Breeders and puppy owners, is safety at the Veterinarian, from birth to 16-20 weeks of age. Puppies should never be placed on the floor at a Vet clinic, or be allowed to meet strange dogs. Remember, eventhough you are there with your healthy puppy for a wellness check, there are other animals there who are sick. Inside the exam room, the veterinary staff will take precautions to protect your pet, such as cleaning off the exam table with disinfectants and washing their hands between patients.