Duration of immunity in cats after vaccination or naturally acquired infection

Abstract

The necessity for cats to be vaccinated annually against common pathogens has been questioned because sarcomas have infrequently been reported at the injection site. However, with few exceptions, the duration of immunity induced by vaccination or infection is uncertain, and there may therefore be a risk associated with a decision not to revaccinate. This article reviews the information available about the duration of immunity induced by vaccination or infection in cats, and reveals many shortcomings that make blanket recommendations impossible. Each vaccine must be considered individually.

Response of feral cats to vaccination at the time of neutering

“…Vaccination of feral cats at the time of neutering may protect them for much of their remaining life span because immunity that develops following vaccination has been shown to persist for a minimum of 3 to 7 years in most cats. 28,29,[37][38][39] Ideally, feral cats should be recaptured and receive booster vaccinations, particularly with a vaccine against RV, according to the guidelines established by the American Association of Feline Practitioners. 40 The 2 FVRCP-FeLV vaccines used in the present study contained inactivated viruses or MLVs, and both induced protective antiviral antibody titers in most cats.…”

Duration of immunity induced by companion animal vaccines

“…The resistance of older animals to many diseases also complicates challenge experiments. Some models used to challenge young animals may not produce disease in older dogs and cats (Scott and Geissinger, 1999;Coyne et al, 2001aCoyne et al, , 2001bMouzin et al, 2004a). For example, after infection with feline panleukopenia virus, adult cats may remain asymptomatic despite shedding virus (Scott and Geissinger, 1999).…”

“…Another study reported complete protection for at least 2 years after vaccination with an inactivated vaccine (Ackermann and Dorr, 1983). Titers correlate well with protection from this disease (Larson, 1996;Tizard and Ni, 1998;Coyne et al, 2001a;Gaskell et al, 2002;Lappin et al, 2002). SN titers stated to be protective vary from 1 : 8 to 1 : 40 (Tizard and Ni, 1998;Gaskell et al, 2002;Mouzin et al, 2004b).…”

“…When immunity after an infection is partial or short lived, the vaccine response is likely to have the same limitation. Feline upper respiratory infections with FHV-1 or FCV, for example, are followed by only partial immunity, and vaccines against these organisms behave similarly (Coyne et al , 2001 a ; Gaskell et al , 2002). In addition, the DOI induced by vaccines for systemic diseases is expected to be greater than for mucosal diseases (Schultz, 2006).…”

“…Adequate immunity in sufficient number of animals can prevent an agent from being readily transmitted within the population, thus decreasing the level of exposure for individual animals. The threshold of population immunity has not been established for most canine or feline diseases (Coyne et al , 2001 a ). However, it is known that rabies transmission effectively stops when more than 70% of dogs are immune (Coleman and Dye, 1996).…”