Objective—To determine whether a herpesvirus isolated
from the semen of a North American elk was
related to bovine herpesvirus 1 (BHV-1).
Sample Population—Semen from 1 healthy bull elk
and 2 subtypes of BHV-1 (BHV-1.1 and BHV-1.2).
Procedures—A virus with cytopathic and electron
microscopic characteristics consistent with an alphaherpesvirus
was isolated from elk semen, using fetal
bovine kidney cells. Cross-neutralization assays were
performed with antisera against BHV-1 and the elk
herpesvirus (ElkHV). Restriction endonuclease
digests of ElkHV DNA were compared with digests of
BHV-1.1 and BHV-1.2 DNA. A portion of the ElkHV
DNA polymerase gene was amplified with consensus
primers by use of the polymerase chain reaction and
sequenced. Sequence was compared with known
sequences of other herpesviruses. An immunoperoxidase
monolayer assay was used to determine reactivities
of 22 BHV–1-specific monoclonal antibodies
(mAb) against ElkHV. In vitro neutralizing activities of
the reactive mAb were determined by use of a
Results—Results of cross-neutralization assays indicated
that ElkHV was serologically related to BHV-1.
Endonuclease digestion of ElkHV DNA generated
fragments that were distinct from those of BHV-1.
Nucleotide sequencing confirmed that ElkHV is an
alphaherpesvirus closely related to but distinct from
BHV-1. Six of 22 BHV–1-specific mAb reacted against
ElkHV; 2 of these 6 also neutralized in vitro infectivity
Conclusions and Clinical Relevance—ElkHV is antigenically
and genetically distinguishable from BHV-1.
However, the viruses are serologically related and
share at least 6 antigenic determinants, one of which
is a major neutralizing determinant. (Am J Vet Res
Objective—To determine whether maternally derived antibodies interfere with the mucosal immune response following intranasal (IN) vaccination of newborn calves with a multivalent modified-live virus vaccine.
Design—Randomized controlled clinical trial.
Animals—23 newborn Holstein bull calves.
Procedures—Calves received colostrum and were assigned to group A (unvaccinated control calves), group B (IN vaccination on day 0), or group C (IN vaccination on days 0 and 35). Serum and nasal secretion sample (NSS) titers of antibodies specific for bovine herpesvirus 1, bovine viral diarrhea virus 1, and bovine viral diarrhea virus 2; WBC counts; and NSS interferon concentrations were determined up to day 77.
Results—Calves had high serum titers of maternally derived antibodies specific for vaccine virus antigens on day 0. High IgA and low IgG titers were detected in NSSs on day 0; NSS titers of IgA decreased by day 5. Group B and C NSS IgA titers were significantly higher than those of group A on days 10 through 35; group C IgA titers increased after the second vaccination. Serum antibody titers decreased at a similar rate among groups of calves. Interferons were not detected in NSSs, and calves did not develop leukopenia.
Conclusions and Clinical Relevance—IN vaccination of newborn calves with high concentrations of virus-neutralizing antibodies increased NSS IgA titers but did not change serum antibody titers. Revaccination of group C calves on day 35 induced IgA production. Intranasal vaccination with a modified-live virus vaccine was effective in calves that had maternally derived antibodies.