Protection against feline infectious peritonitis by intranasal inoculation of a temperature-sensitive FIPV vaccine.

Cats vaccinated intranasally (i.n.) with a temperature sensitive feline infectious peritonitis virus (ts-FIPV) vaccine were protected against an FIP-inducing challenge.

Evaluation of immunosuppressive effect and efficacy of an improved-potency feline leukaemia vaccine.

An inactivated feline leukaemia vaccine was tested to determine if process improvements would permit it to be effectively used in a two-dose primary regimen versus the three-dose regimen required for a previous vaccine. Twenty-five cats were vaccinated with two subcutaneous doses given 3 weeks apart. Vaccinates and controls were artificially immunosuppressed to enhance susceptibility to challenge, and inoculated with virulent feline leukaemia virus (FeLV) 2 weeks after the second dose.

Characterization of an attenuated temperature sensitive feline infectious peritonitis vaccine virus.

Intranasal administration of a ts-FIPV vaccine protected cats against two rigorous challenges of immunity. Investigations showed that ts-FIP viral RNA synthesis was normal at 39 degrees C and structural proteins were synthesized, but not expressed at the cell surface. Lack of surface expression combined with decreased virus titer indicate that, although structural viral proteins were initially synthesized, they were not packaged into intact virions at the nonpermissive temperature.

Identification of pseudorabies virus-exposed swine with a gI glycoprotein enzyme-linked immunosorbent assay.

A monoclonal antibody specific for the gI glycoprotein of virulent pseudorabies virus was produced and used to affinity purify gI glycoprotein. The purified gI was used in an enzyme-linked immunosorbent assay (ELISA) that identified and differentiated field virus-exposed animals from animals vaccinated with gI-deleted virus. The gI ELISA was evaluated by comparing it with the virus neutralization test and with a standard ELISA which does not distinguish between vaccinated and naturally infected animals.

Efficacy of viral components of a nonabortigenic combination vaccine for prevention of respiratory and reproductive system diseases in cattle.

Efficacy and safety of components of an IM-administered vaccine for prevention of infectious bovine rhinotracheitis virus (IBRV), parainfluenza type-3 (PI-3) virus, bovine viral diarrhea virus (BVDV), and respiratory syncytial virus (RSV) infections and campylobacteriosis and leptospirosis were evaluated in cattle, including calves and pregnant cows. Challenge of immunity tests were conducted in calves for IBRV, PI-3 virus, or BVDV vaccinal components. All inoculated calves developed serum-neutralizing antibodies and had substantially greater protection (as measured by clinical rating systems) than did controls after challenge exposure to virulent strains of IBRV, PI-3 virus, BVDV, or RSV.

Immunogenicity of a Moraxella bovis bacterin containing attachment and cornea-degrading enzyme antigens.

An adjuvanted Moraxella bovis bacterin containing attachment antigens and cornea-degrading enzyme antigens protected cattle from infectious bovine keratoconjunctivitis (IBK) when experimentally challenged with homologous and heterologous challenge cultures of M. bovis. This bacterin also protected cattle against field exposure to M.

Feline leukaemia vaccine protection against viral latency.

Seventeen cats, which were previously vaccinated with a subunit, feline leukaemia vaccine (Leukocell) and subsequently challenged with virulent feline leukaemia virus (FeLV), were tested at 2 to 4 years postchallenge for reactivation of latent FeLV infections. Administration of weekly doses of methylprednisolone induced significant decreases in lymphocyte numbers, but did not reactivate virus in bone marrow cultures from 15 cats in vivo or in vitro. These cats were observed to be neither persistently or latently viraemic prior to corticosteroid administration.

An enzyme immunoassay for measuring Escherichia coli pilus antigens.

Quantitative enzyme-linked antibody centrifuge (ELAC) assays have been developed for measuring Escherichia coli adhesion pilus antigens K99, K88, 987P and F41 in E. coli bacterins used for protecting newborn animals against neonatal enteric colibacillosis. The test consists of reacting an alkaline phosphatase conjugate of specific pilus antigen antibody directly with dilutions of the bacterin on test and a standard reference bacterin.

Cell-mediated immune response to rabies virus in dogs following vaccination and challenge.

Peripheral blood lymphocytes (PBL) from non-vaccinated dogs and from dogs either vaccinated intramuscularly (IM) or subcutaneously (SC) with an inactivated rabies virus vaccine (Rabguard-TC, Norden Laboratories, Lincoln, NE) or intramuscularly with an attenuated rabies virus vaccine (Endurall-R, Norden Laboratories, Lincoln, NE) were exposed in vitro to rabies virus. Blastogenesis of PBL was measured by incorporation of 3H-thymidine into the DNA of proliferating cells in the presence of a suboptimal concentration of phytohemagglutinin (PHA). Following the first vaccination, there was no difference in the blastogenic response of lymphocytes from dogs vaccinated IM with either the inactivated or attenuated rabies virus vaccines.

Development of a modified live, canine origin parvovirus vaccine.

A modified live, canine origin parvovirus vaccine was tested for safety, efficacy, and clinical performance. The vaccine protected dogs from challenge of immunity with canine parvovirus (CPV) that caused clinical illness in all nonvaccinated dogs. Vaccinates all developed CPV serum neutralization antibody titers, with a mean value of 1,664.

Vaccination of cattle and sheep with a combined Clostridium perfringens types C and D toxoid.

Cattle and sheep (30 each) were vaccinated with a combined Clostridium perfringens type C and C perfringens type D toxoid. Vaccination and blood sample collections were made every 2 weeks over a period of 8 weeks. Increases in antitoxin titers occurred after the 2nd administration of the 2.

Effect of age and pregnancy on the antibody and cell-mediated immune responses of horses to equine herpesvirus 1.

The cell-mediated immune response and antibody response of horses of varying ages and of pregnant horses to equine herpesvirus 1 antigen were examined. Six to eight month old horses showed either no increase or slight increases in anti-equine herpesvirus 1 serum neutralizing antibody following vaccination and revaccination with a modified live equine herpesvirus 1 vaccine. However, these same horses showed a marked increase in the cell-mediated immune response to equine herpesvirus 1 as measured by the lymphocyte transformation test.

Studies on the antigenicity of an inactivated, aluminum hydroxide adjuvant equine influenza vaccine.

An inactivated, aluminum hydroxide adjuvant equine influenza vaccine was tested in horses and guinea pigs to determine the levels of antigen that would elicit maximum serological responses. Vaccine containing serial twofold increments of A/Equi-1/Prague and A/Equi-2/Miami strains of equine influenza virus was administered to random groupings of both types of test animals. The hemagglutination inhibition antibody response for each group was then measured.

Field trial evaluation of a reo-coronavirus calf diarrhea vaccine.

Field trials were conducted using an experimental, modified live virus, oral vaccine for prevention of reo- and coronavirus calf diarrhea. Prior to the trials, one or both of the specific causative agents were identified from affected calves in each participating herd. In 21 herds, sequential trials were conducted in which results of uninterrupted vaccination were compared with disease rates during a preceding or subsequent control period.