Inhibition of virus replication in the tonsils of pigs previously vaccinated with a Chinese strain vaccine and challenged oronasally with a virulent strain of classical swine fever virus.

After an oronasal (O.N.) infection with classical swine fever (C.

An epizootic of African swine fever in Belgium and its eradication.

In March 1985 an outbreak of African swine fever was diagnosed in Belgium, in the province of West Flanders. The source of the infection was probably pork imported from Spain which was fed to only one boar. A total of 12 farms were infected in the epizootic out of 185 farms which were in contact.

Epizootics of respiratory tract disease in swine in Belgium due to H3N2 influenza virus and experimental reproduction of disease.

In Belgium, influenza virus was isolated from swine in 22 epizootics of respiratory tract disease in swine during 1984. In 8 of the epizootics, H3N2 influenza virus, related to the A/Port Chalmers/1/73 strain, was isolated. Intratracheal inoculation of the isolates induced clinical signs.

Vaccination of cattle against pseudorabies (Aujeszky's disease) with homologous virus (herpes suis) and heterologous virus (herpes bovis 1).

Study was made to determine whether vaccination of cattle against pseudorabies (PR; Aujeszky's disease) affords protection upon subsequent intranasal challenge exposure with virulent virus. Vaccinations were performed with a commercially available oil-adjuvant PR virus vaccine, in some cases supplemented with A1(OH)3 (given subcutaneously), with the attenuated NIA4 strain of PR virus (given intranasally), and with a commercially available temperature-sensitive mutant of bovine herpesvirus-1 (infectious bovine rhinotracheitis [IBR] virus) given intranasally. Challenge exposure was performed intranasally with 10(3) median lethal doses (LD50) of the virulent PR virus.

Capacity of attenuated swine fever vaccines to prevent virus carriers in the vaccinated pigs, after contact with field virus.

Virus carriers have been detected in pigs vaccinated with attenuated Swine Fever vaccines after challenge with field virus. Virus carriers were found only if the vaccination was made with 20 PD50 or less. Clinical protection was obtained already with 8 PD50.

Effects of oxyamylose and polyacrylic acid on foot-and-mouth disease and hog cholera virus infections.

Two interferon-inducing polycarboxylates were tested for antiviral activity on foot-and-mouth disease (FMD) virus infections in mice, guinea pigs, and swine. Polyacrylic acid, given intraperitoneally, had a protective effect on infection by FMD virus administered in the peritoneal cavity of mice and in the foot pad of guinea pigs. Chlorite-oxidized oxyamylose (COAM) was effective in mice at a dosage of 2 mg/kg.