Vaccines; How they work and when they should NOT be given


I am writing this blog in response to a certain case that recently came to my attention.  The dog was brought in to his regular veterinarian for an ongoing, extreme weight loss; twenty pounds.  His regular vet had been seeing him for the weight loss all along, with no answers.  A few conventional medications had been tried, along with routine worming to no avail.  Now he was experiencing head tremors and diarrhea.  At this visit, he was due for Rabies, Kennel Cough and Lyme vaccines.  They were given that day; although the owners were informed their dog likely had inoperable cancer.  Why does this happen?  Even if this medical procedure did nothing to the already taxed immune system, what possible advantage would there be to vaccinating a terminal patient?  Why is this bad or improper medicine?  How can you prevent it? 

First, let’s learn how the immune system and vaccines work, then why this is not the time for them to be given. 

How the immune system works

The immune system is the body's defense against infectious organisms and other invaders. Through a series of steps called the immune response, the immune system attacks organisms and substances that invade body systems and cause disease.  The immune system is made up of a network of cells, tissues, and organs that work together to protect the body. The cells involved are white blood cells which come in two basic types that combine to seek out and destroy disease-causing organisms or substances.

White blood cells are produced or stored in many locations in the body, including the thymus, spleen, and bone marrow. There are also clumps of lymphoid tissue throughout the body, primarily as lymph nodes, that house the white blood cells.  The white blood cells circulate through the body between the organs and nodes by means of lymphatic vessels and blood vessels. In this way, the immune system monitors a body for germs or substances that might cause illness.   

The two kinds of white blood cells are B lymphocytes and T lymphocytes. White blood cells start out in the bone marrow and either stays there and mature into B cells, or they leave for the thymus gland, where they mature into T cells. B lymphocytes and T lymphocytes have separate functions: B lymphocytes are like the body's military intelligence system, seeking out their “enemy” and sending defenses to lock onto them. T cells are like the soldiers, destroying the invaders that the intelligence system has identified. 

How vaccines work 

Vaccines teach your immune system by mimicking a natural infection.  By artificially injecting the body with viral or bacterial components, it is believed that the body will “remember” this and put up a good fight if they actually virus or bacteria ever do invade the body.  This fight is done primarily by the body’s white blood cells. 

The rabies vaccine, for example, contains an inactivated form of the virus that doesn’t cause actual disease or reproduce very well. This vaccine is injected into your dog. Your dog’s white blood cells can’t tell that the vaccine viruses are duds, so they gobble up the viruses as if they were dangerous.  The alarm is sounded, and his immune system goes into action. Rabies specific T cells rush out to meet the “enemy”. B cells secrete rabies antibodies. But the battle is over quickly. The inactivated virus in the vaccine can’t put up much of a fight. The fake infection is cleared, and he is left with a supply of memory T and B cells to protect him against rabies.  

Why a sick pet should not be vaccinated 

So, from the brief information above, you can see that the immune system is very busy if it is reacting to any type of invader or infectious organisms.  This could be a vaccine, a bacterial ear infection, a urinary tract infection, autoimmune disease like lupus or an immune disaster such as cancer.   If a vaccine is given when the system is already working hard it makes sense that this would be potentially harmful.  Best case scenario is that the immune system steps up and deals with both the vaccine and the illness.  Worst case is the immune system “breaks” and you either have improper healing of disease or improper immunity with the injected vaccine.  Common sense tells us that vaccinating while a pet is already sick is not good or proper medicine.  Even the vaccine manufactures tell us this on each and every package insert.  Here is a typical vaccine product insert: 

  • Store at 2°C to 7°C. Prolonged exposure to higher temperatures and/or direct sunlight may adversely affect potency. Do not freeze. Use entire contents when first opened. Sterilized syringes and needles should be used to administer this vaccine. Do not sterilize with chemicals because traces of disinfectant may inactivate the vaccine. Burn containers and all unused contents. Contains gentamicin as preservative. Vaccination of pregnant bitches should be avoided. As with many vaccines, anaphylaxis may occur after use. Initial antidote of epinephrine is recommended and should be followed with appropriate supportive therapy. This product has been shown to be efficacious in healthy animals. A protective immune response may not be elicited if animals are incubating an infectious disease, are malnourished or parasitized, are stressed due to shipment or environmental conditions, are otherwise immunocompromised, or the vaccine is not administered in accordance with label directions.

How to prevent this from happening to my dog 

You, the owner, have to step up and become an advocate for your pet.  There is no easier or more effective way.  You must tell your veterinarian no, you will not vaccinate your dog while he is experiencing ill health.  You have every right to reject the vaccine and if your veterinarian demands it be done, he is not practicing proper medicine.  Tell your veterinarian you will return for the vaccine (if you are so inclined) when your dog is healthy once again.  By returning when your dogs is completely healthy the vaccine will give your pet the best immunity.  (Or better yet, tell your veterinarian you would like to have vaccine blood titers done instead!) 

Making safe vaccines

No vaccine is perfectly safe or effective. Each dog’s immune system works differently, so sometimes a dog will not respond to a vaccine. Commonly, dogs can experience side effects such as fever, soreness, or redness at the injection site. Adverse reactions are reported so rarely because they can be difficult to detect. For this reason, it is difficult to confirm actual numbers of vaccine reactions. Sometimes a dog may have a serious adverse reaction to a vaccine, such as an allergic reaction that causes hives and difficulty breathing or even life threatening side effects like bleeding disorders. All vaccine reactions should be reported to the

Be aware. Be knowledgeable. Be proactive.

For more information on vaccination, please take the time to check out these links: 
In Health, 
Gina Snow LVT