host posted on May 17, 2011 14:20
Vaccine Basics
Most vaccines work by causing the body to produce antibodies or otherwise sensitize the immune system so that if a natural infection occurs the body is ready to fight it. The vaccines are usually either killed or modified strains of the infectious organism that will induce the immune response without causing disease. Some vaccines may produce an immunity that is lifelong while others produce a very short duration of immunity. Most vaccines have adjuvants (chemicals added to the vaccine) that help them to provide stronger and longer immunity. The level of protection a vaccine provides can vary depending on the type of vaccine, the adjuvants and the animals immune system.
Vaccine Problems
Vaccines have been implicated as causes of many types of problems including autoimmune disease, cancer and death. We know that a very small number of animals may have anaphylactic reactions to any medication we give including vaccines. This is similar to what happens when a person who is very allergic to bee venom gets stung by a bee. Vaccine manufacturers have identified and removed most of the substances that caused these reactions. Holistic practitioners and some researchers have associated vaccines with autoimmune diseases where the animals immune system starts attacking its own body. This has not been conclusively proven via scientific methods and research is continuing. The media has picked up on research involving the occurrence of a very specific type of cancer called a sarcoma at the location on the animals body where vaccines are given. The research has been going on since the 1980's and still does not have a conclusive answer. Most of the research involves cats vaccinated with a feline leukemia vaccine although sarcomas have been associated with other species and other drugs. The exact number of cats that have vaccine related sarcomas is not known. It has been speculated that it is as high as 1 in 1000 and as low 1 in 10000. These tumors can be very invasive and malignant and can require radical surgery and chemotherapy. It should be noted that many animals develop lumps at a vaccine site that are not cancer. These non-cancerous lumps are called granulomas and they usually resolve without treatment in 2-4 weeks. The problem is that there is no way to tell the difference without doing a biopsy. It is always a good idea to have your veterinarian check any "lump" you find on your pet.
Which vaccines are needed?
Vaccine protocols vary widely from region to region and clinic to clinic. What follows is the current recommendation for vaccination of adult dogs and cats at 303 Animal Clinic and our rationale behind our plan. Adult dogs and cats are both required by Texas state law to have a rabies vaccine every 3 years. Animals in the large cities are at as much risk as those in the country. We believe that each animal is an individual and recommendations vary from animal to animal. We recommend that normal healthy adult dogs get a Distemper/Parvovirus/Corona virus/Adenovirus/Parainfluenza vaccine every 3 years. If a dog has had a reaction to this vaccine in the past or has some unrelated health problem then we may recommend delaying or skipping the vaccine. Other vaccines such as a Bordetella(kennel cough) or Lyme are given only to animals that are at risk of exposure to these diseases. We recommend that normal healthy adult cats get a Feline Viral Rhinotracheitis/Calicivirus/Panleukopenia/Chlamydia vaccine every 3 years. Just like with the dog vaccine, this one may be delayed or skipped if the cat has a history of reactions or certain health problems. Cats that spend time outdoors are at risk of exposure to Feline Leukemia so these cats are given a yearly Feline Leukemia vaccine. Since this is the vaccine that has the greatest potential for the development of a sarcoma, we must thoroughly evaluate the risk of exposure to the leukemia virus versus the risk of sarcoma development to decide if an individual cat should get this vaccine.
What does the future hold?
Veterinary medicine often follows the route taken by human medicine and vaccine protocols will probably not be an exception. Pediatricians routinely give children vaccinations and veterinarians will continue to give puppies and kittens a series of vaccines to build a protective level of immunity. Adults are given vaccines when they are at risk of exposure to certain diseases. For example, most human adults do not get rabies vaccines but students at the veterinary college are vaccinated against rabies because their future jobs will put them at a high risk of exposure to rabid animals. Veterinarians may have their blood tested every 2 years to see if the level of antibodies in their blood is protective. If the level falls too low then a booster vaccine is given. Some veterinary colleges have already started a program for the animals they vaccinate where blood is taken for testing first and then vaccinated if the tests indicate a need for booster vaccines.Research is still in progress to develop cost effective and timely testing like this for animal vaccines. Research is also needed to determine what levels of antibodies in our pets are protective for various diseases.
Conclusion
Vaccines are an effective way to prevent many of the deadly diseases that can affect our pets. Many more pets die each year from the lack of proper vaccinations than from reactions or problems with the vaccines. Our understanding of the way these vaccines work as well as their potential hazards is increasing as research continues. Remember that each animal is an individual and needs individual treatment. Discuss any questions about the safety and efficacy of vaccines with your veterinarian to develop the protocol that is best for your pets. Always have any unusual "lump" on your pet checked by your veterinarian.