Vaccination with inactivated virus but not viral DNA reduces virus load following challenge with a heterologous and virulent isolate of feline immunodeficiency virus.

Vaccination with an inactivated virulent feline immunodeficiency virus engineered to express high levels of Env.

An inactivated virus vaccine was prepared from a pathogenic isolate of feline immunodeficiency virus containing a mutation that eliminated an endocytic sorting signal in the envelope glycoprotein, increasing its expression on virions. Cats immunized with inactivated preparations of this modified virus exhibited strong titers of antibody to Env by enzyme-linked immunosorbent assay. Evidence of p...

Three-year duration of immunity in cats following vaccination against feline rhinotracheitis virus, feline calicivirus, and feline panleukopenia virus.

Forty-two seronegative cats received an initial vaccination at 8 weeks of age and a booster vaccination at 12 weeks. All cats were kept in strict isolation for 3 years after the second vaccination and then were challenged with feline calicivirus (FCV) or sequentially challenged with feline rhinotracheitis virus (FRV) followed by feline panleukopenia virus (FPV). For each viral challenge, a sepa...

Effectiveness of two H9N2 low pathogenic avian influenza conventional inactivated oil emulsion vaccines on H9N2 viral replication and shedding in broiler chickens

The objective of this study was to compare the effect of two conventional H9N2 avian influenza (AI) vaccines on replication and shedding of the H9N2 AI virus in broiler chickens. These inactivated oil emulsion vaccines contain either a UAE or an Iranian H9N2 AI isolate. One hundred and fifty one-day-old commercial broiler chickens were randomly divided into six groups. The birds, except for the...

DNA immunization and viral load in vaccinated trout following experimental infection with infectious pancreatic necrosis virus (IPNV)

Impact of a modified-live porcine reproductive and respiratory syndrome virus vaccine intervention on a population of pigs infected with a heterologous isolate.

The objectives of this study were to evaluate the effects of a therapeutic vaccine intervention with a modified-live porcine reproductive and respiratory syndrome virus (PRRSV) vaccine on the dynamics of a heterologous viral infection in a population of pigs, and to determine the clinical and virological response of previously exposed and vaccinated pigs against a second virulent heterologous c...