Biphasic immune responses of cats under controlled infection with a feline enteric coronavirus-79-1683 strain

Abstract

Kittens inoculated orally with 102 PFU of feline enteric coronavirus developed no antibody to the virus despite the repeated challenges. However, they developed antibody for a long period with 5×103-1.6×105 (mean 3×104) and with 2.5×103-2×104 (mean 6×103) immunoperoxidase antibody titer when they were challenged with 105 and 103 PFU of virus following previous challenges, respectively. Viremia was found when kittens were inoculated with 105 PFU of virus, but not with 103 PFU of virus. The dose of 103 PFU of virus seemed to be a lower limit to establish infection. These results indicate that local infection induces a low antibody response and systemic infection induces a high antibody response. © 1995, JAPANESE SOCIETY OF VETERINARY SCIENCE. All rights reserved.