AAFP Feline Vaccination Guidelines
Introduction
Extended vaccination intervals recommended in the 2000 Report of the American Association of Feline Practitioners (AAFP) and Academy of Feline Medicine Advisory Panel on Feline Vaccines referenced a foundation study conducted by Dr. Fred Scott. His 1997 study, which reviewed serology data, was published in the 1997 Feline Practice, while his 1999 study reviewed the challenge work and was published in the 1999 American Journal of Veterinary Research. Dr. Scott's study was not funded by Fort Dodge Animal Health, but reported his study was done using a serial of Fort Dodge Animal Health Fel-O-Vax® PCT. The challenge study took place 7.5 years following the last vaccination.
Study Design1
| Method: | |
| Number of cats in the study | 17 |
| Vaccinates | 9 |
| Unvaccinated controls | 8 |
| Vaccination with Fel-O-Vax® PCT was given at 8 and 12 weeks of age. Challenge occurred 7.5 years later. | |
| Results: | |
| Feline panleukopenia virus (FPV) challenge: | |
| Preventable Fraction | 100%* |
| *Controls did not show clinical signs of disease. | |
| Feline herpesvirus (FHV) challenge: | |
| Preventable Fraction | 52% |
| Feline calicivirus (FCV) challenge: | |
| Preventable Fraction | 63% |
Commentary
The data from this study clearly show the level of protection for two of the three virus challenges is still substantial, even at 7.5 years post vaccination. However, it also shows the level of immunity seems to have fallen off somewhat from original levels measured earlier in the study. For panleukopenia, none of the controls developed clinical signs of disease, which is typical of a panleukopenia challenge of older cats. The result of the low challenge level demonstrates the preventable fraction calculation is inconclusive, and the level of actual protection is difficult to determine. The low number of challenged cats is not a completely reliable indicator of how client owned cats would withstand a similar challenge.
It is the opinion of Fort Dodge Animal Health that this one study is interesting, but is not sufficient evidence to support a three-year revaccination interval for all cats. Note the only vaccine used in this study was a killed, adjuvanted product, Fel-O-Vax® PCT. It is not scientifically sound to take this data and conclude all adjuvanted or all non-adjuvanted products would provide similar protection. Another unfounded conclusion some have drawn is that Dr. Scott's study supports lengthy vaccination intervals. While this study is promising, the results are not conclusive with regard to the long-term duration of immunity of Fel-O-Vax® PCT. Dr. Scott's work should certainly not be "stretched" to fit all products for all cats in all situations. This study was never designed for that purpose.
