Cat Vaccination Protocols


“Anytime you inject anything into a patient you have the potential of killing them.”

--Prof. Ron Schultz, DVM.

The practice of giving cats several different vaccinations against various diseases all at the same time early in life and then again every year as “boosters” for the rest of their lives is coming to a close. This is for two primary reasons: animals can have adverse reactions to vaccinations that can impair their health for the rest of their lives; routine “booster” shots are not needed since earlier vaccinations have given animals sufficient immunity to the diseases in question.

First, kittens should not be given vaccinations before 8-10 weeks of age since this can interfere with the natural immunity in their systems conferred by the colostrum or first milk of their mothers. But if the immune status of the mother is unknown, as is the situation for many to-be-adopted kittens in animal shelters, vaccinations at an earlier age between 5-6 weeks is the usual protocol. Adult animals in a compromised immune state, as for example those who are ill, injured, or being given an anesthetic and operated on, such as being spayed or castrated, or for any other surgical procedure, are pregnant or nursing, or are old and infirm, should not be vaccinated.

Rabies vaccinations, unless in-field conditions make this logistically difficult, should never be given at the same time other combined vaccinations are given. Separate by at least 3 weeks.

For minimal basic vaccination protocols, developed by Dr. Jean Dodds, see Table 1.

If your cat received all core vaccines by 16 weeks of age, have antibody blood titers evaluated at 1 year of age if you have reservations about re-vaccination.

No vaccine can guarantee immunity, since different strains of infective agents may be involved, and animals who are stressed, suffering from poor nutrition, genetic susceptibility and concurrent disease may have impaired immune systems and lowered resistance to disease. But this does not mean that they should never be vaccinated or be routinely re-vaccinated just in case, because vaccinations can cause further immune system impairment and a host of health problems—the so called vaccinosis diseases— that these new vaccination protocols are aimed at minimizing.


Age of Kittens: Vaccine Type

8 weeks: Panleukopenia, calicivirus, herpes virus, trivalent killed vaccine or Recombinant MLV

12 weeks: Same as above

20 weeks or older: Rabies - if allowable by law

1 year: Panleukopenia, calicivirus, herpes virus (0ptional)

1 year: Rabies, killed 3-year product (give 3-4 weeks apart from other vaccines booster), if required

W. Jean Dodds, DVM. Hemopet, 938 Stanford Street, Santa Monica, CA 90403; 310-828-4804; Fax 310-828-8251; e-mail


from: Schultz, Ford, Olsen, Scott. Vet Med, 97: 1-13, 2002


In an article in DVM360 entitled Vaccination: An Overview Dr. Melissa Kennedy states that of the two types of adverse reactions:

“Adverse reactions have also become a major concern in small animal medicine. … These fall into two general categories. The first is immediate hypersensitivity. This may be a local or systemic response, and is due to pre-existing antibody to the agent. This is the classic “allergic reaction” to the vaccine and can be life-threatening. The second is a delayed response, requiring days or longer to develop. The vaccine, seen as foreign, elicits a significant inflammatory response and is especially true for adjuvanted vaccines. This response can manifest as a granuloma, or more seriously, a fibrosarcoma.”

Veterinarians in the U.K are being urged to adopt the vaccinations of cats and dogs against “core” diseases (excluding rabies) advocated by the World Small Animal Veterinary Association to its 86 member countries.* They are similar to those that I and other veterinarians in the U.S. and Canada have been advocating for the past 15 years and more on the basis of sound science—advances in vaccinology, immunology and blood titer testing rather than personal opinion, to optimize the benefits and minimize the risks.

The core vaccinations against feline parvovirus, feline herpesvirus type 1 (rhinotreacheitis) and feline calicivirus are given to kittens at 8, 12,16 weeks or older, 26 weeks and at 52 weeks if not given at 26 weeks of age. Then for low risk cats who live indoors, this combination of vaccines is recommended to be given at 4, 7 and 10 years of age with the option of only re-vaccinating against feline herpesvirus type 1 and feline calicivirus if the serum titer readings are high for feline parvovirus immunity indicating continued effective immunity.

In sum, these core vaccinations need not be given annually. Other vaccinations (non-core) may be called for depending on the region, outbreaks of infections and associated exposure risks.

*See Michael J. Day, Small animal vaccination: a practical guide for vets in the UK. The Veterinary Record, In Practice, 39: 110-118 2017.