Vaccinosis is the term given to the chronic reaction of the body against repeated immunization. Many holistic veterinarians and owners are concerned about the frequent (and most likely unnecessary) immunization of pets for just about every disease imaginable.
Minor short term side effects often seen following immunization include fever, stiffness, joint soreness, lethargy, and decreased appetite.
A number of more serious conditions have been proven or proposed to be the result of excessive immunization, and animals run the risk of adverse reactions as increasing amounts of foreign antigens are injected into them. Since vaccination involves altering the immune system, it is not surprising that occasionally adverse effects involving the immune system as a result of immunization also occur.
These include injection site sarcomas (an aggressive cancer of cats that may occur in 1:1000-1:10000 cats following any injection; vaccines are implicated more than other injectable medications,) collapse with autoimmune hemolytic anemia (decreased red blood cell count) or thrombocytopenia (decreased platelet count,) liver failure, kidney failure, bone marrow suppression, immune suppression, systemic lupus erythematosus, rheumatoid arthritis, food allergy, atopic dermatitis (allergic disease as a result of immunization is suspected to occur as a result of an augmented immune response to the vaccine and/or other allergens/immugens, the so-called "allergic breakthrough" phenomenon,) glomerulonephritis/renal amyloidosis (different types of immune kidney diseases,) seizures, bloating, hypothyroidism, and hyperthyroidism. The administration of vaccines may also interfere with the interpretation of various test results (cats vaccinated against any disease may show a positive titer on the standard corona virus test, called the FIP test.)
Injection site sarcomas are a particularly devastating side effect of immunizing cats.
These aggressive tumors usually occur between 3.5 months and 3.5 years following injection. Any vaccine (or injectable substance) can be associated with sarcomas; recently the injectable flea control product Program has been reported to possbily be associated with injection site sarcomas in 3 cats.
Following injection, inflammation results (usually as a result of the adjuvant in the medication or vaccine; the adjuvant is a chemical added to increase local inflammation and a more intense immune reaction.) The amount of chronic inflammation occurring at the site of the injection is related to the cat's risk of developing injection site sarcoma (the more inflammation the greater the risk.) Since vaccines are often given annually in the same site on the cat's body, it is no surprise that risk increases with the number of vaccines given in 1 site.
Not all cats will develop injection site sarcoma as a result of an injection (most cats do not develop injection site sarcomas despite inflammation at the injection site.) Apparently there is some interaction between intense inflammation and tumor oncogenes which ultimately results in tumor formation following injections. In fact, preliminary research has shown that sarcomas associated with vaccines had overexpression of the c-jun gene (a gene that is related to cancer development in animals species (an oncogene),) when compared to sarcomas not related to vaccine injection. The working hypothesis as to why some rare cats develop injection site sarcomas (and most cats do not) is that something in the injections (probably adjuvant) causes persistent inflammation at the injection site, which in some way stimulates the cat's oncogenes to overreact and develop tumors. In other words, it appears that some cats may be genetically predisposed to developing injection site sarcomas, and the inflammation following immunization is the trigger to set this reaction in motion.
When vaccinosis occurs, holistic doctors may prescribe a homeopathic or herbal detoxification protocol. Many doctors use the homeopathic remedy Thuja to minimize side effects from vaccines.