A single vaccination with an inactivated bovine respiratory syncytial virus vaccine primes the cellular immune response in calves with maternal antibody

<p>Abstract</p> <p>Background</p> <p>The efficacy of a single dose of an inactivated bovine respiratory syncytial virus (BRSV) - Parainfluenaza type 3 (PI3) - <it>Mannheimia haemolytica </it>(<it>Mh</it>) combination vaccine, in calves positive for maternal antibodies, was established in a BRSV infection study.</p> <p>Results</p> <p>As expected the single vaccination did not have any effect on the decline of BRSV-specific neutralising or ELISA antibody. The cellular immune system was however primed by the vaccination. In the vaccinated group virus excretion with nasal discharge was reduced, less virus could be re-isolated from lung tissues and the lungs were less affected.</p> <p>Conclusions</p> <p>These results indicate that a single vaccination with an inactivated BRSV vaccine was able to break through the maternal immunity and induce partial protection in very young calves. It can be speculated that the level and duration of protection will improve after the second dose of vaccine is administered. A two-dose basic vaccination schedule is recommended under field conditions.</p

Review on bovine respiratory syncytial virus and bovine parainfluenza : usual suspects in bovine respiratory disease : a narrative review

Bovine Respiratory Syncytial virus (BRSV) and Bovine Parainfluenza 3 virus (BPIV3) are closely related viruses involved in and both important pathogens within bovine respiratory disease (BRD), a major cause of morbidity with economic losses in cattle populations around the world. The two viruses share characteristics such as morphology and replication strategy with each other and with their counterparts in humans, HRSV and HPIV3. Therefore, BRSV and BPIV3 infections in cattle are considered useful animal models for HRSV and HPIV3 infections in humans. The interaction between the viruses and the different branches of the host's immune system is rather complex. Neutralizing antibodies seem to be a correlate of protection against severe disease, and cell-mediated immunity is thought to be essential for virus clearance following acute infection. On the other hand, the host's immune response considerably contributes to the tissue damage in the upper respiratory tract. BRSV and BPIV3 also have similar pathobiological and epidemiological features. Therefore, combination vaccines against both viruses are very common and a variety of traditional live attenuated and inactivated BRSV and BPIV3 vaccines are commercially available

Effect of an inactivated bluetongue serotype 8 vaccine on semen quality in rams.

The aim of this study was to determine whether a single dose of an inactivated bluetongue virus serotype 8 (BTV-8) vaccine altered semen quality in rams. Twenty sexually mature rams were assigned to three experimental groups: two groups of four animals were vaccinated and a third group of four animals was unvaccinated. The first group included rams with a history of natural BTV-8 infection in 2007 and the second and third groups included BTV-8 naive rams. Semen was collected prior to vaccination and for 4months post-vaccination. There were no significant differences in semen quality traits, including motility and concentration of spermatozoa, and percentages of living, normal dead and abnormal dead spermatozoa, between vaccinated and unvaccinated groups, or over time (P>0.05). The BTV-8 vaccine tested in this study did not appear to have any adverse effect on semen quality in rams

Early Activation of the Innate Immunity and Specific Cellular Immune Pathways after Vaccination with a Live Intranasal Viral Vaccine and Challenge with Bovine Parainfluenza Type 3 Virus

Bovine parainfluenza type 3 (BPIV3) and bovine respiratory syncytial virus (BRSV) may cause bovine respiratory disease (BRD) in very young calves, and therefore vaccination should induce protection at the youngest age and as quickly as possible. This can be achieved by intranasal vaccination with a vaccine containing live attenuated BRSV and BPIV3 virus strains. The objective of this study was to measure gene expression levels by means of RT-qPCR of proteins involved in the innate and adaptive immune response in the nasopharyngeal mucosae after administration of the above-mentioned vaccine and after challenge with BPIV3. Gene expression profiles were different between (i) vaccinated, (ii) nonvaccinated-challenged, and (iii) vaccinated-challenged animals. In nonvaccinated-challenged animals, expression of genes involved in development of disease symptoms and pathology were increased, however, this was not the case after vaccination. Moreover, gene expression patterns of vaccinated animals reflected induction of the antiviral and innate immune pathways as well as an initial Th1 (cytotoxic) cellular response. After challenge with BPIV3, the vaccinated animals were protected against nasal shedding of the challenge virus and clinical symptoms, and in parallel the expression levels of the investigated genes had returned to values that were found before vaccination. In conclusion, in comparison to the virulent wild-type field isolates, the two virus strains in the vaccine have lost their capacity to evade the immune response, resulting in the induction of an antiviral state followed by a very early activation of innate immune and antiviral responses as well as induction of specific cellular immune pathways, resulting in protection. The exact changes in the genomes of these vaccine strains leading to attenuation have not been identified. These data represent the real-life situation and can serve as a basis for further detailed research. This is the first report describing the effects on immune gene expression profiles in the nasal mucosae induced by intranasal vaccination with a bivalent, live BRSV-BPI3V vaccine formulation in comparison to wild-type infection with a virulent BPI3V strain

Field efficacy of combination vaccines against bovine respiratory pathogens in calves

The efficacy of an inactivated bovine respiratory syncytial virus (BRSV) — bovine parainfluenza type 3 (PI3) — Mannheimia haemolytica ( Mh ) combination vaccine was examined in two field studies. Calves were vaccinated (i) with the inactivated vaccine, (ii) a modified live/killed viral combination vaccine, or (iii) left unvaccinated. The efficacy of the vaccines was judged by the (i) number of treated animals, (ii) number of individual antibiotic treatments per calf and (iii) mortality rates. After vaccination with the inactivated vaccine, the number of calves requiring antibiotic treatment was significantly lower than in the unvaccinated group (odds ratios: 0.26 first study and 0.53 second study), but differences between vaccination with live/killed combination vaccines and controls were not significant (odds ratios: 0.56 and 0.90, respectively). In both studies, a number of unvaccinated controls died due to respiratory disease (4.6% first and 6.7% second study). By contrast, none of the animals vaccinated with the inactivated vaccine died in the first study and only 3.3% in the second study. The mortality rates for the groups vaccinated with the live vaccine (1.3% and 7.8%) were similar to the unvaccinated controls. In summary, these data demonstrate the efficacy of the inactivated vaccine under field conditions

Rift Valley Fever Vaccine Virus Clone 13 Is Able to Cross the Ovine Placental Barrier Associated with Foetal Infections, Malformations, and Stillbirths

Rift Valley fever virus (RVFV) is a mosquito-borne pathogen that affects domesticated ruminants and occasionally humans. Classical RVF vaccines are based on formalin-inactivated virus or the live-attenuated Smithburn strain. The inactivated vaccine is highly safe but requires multiple administrations and yearly re-vaccinations. Although the Smithburn vaccine provides solid protection after a single vaccination, this vaccine is not safe for pregnant animals. An alternative live-attenuated vaccine, named Clone 13, carries a large natural deletion in the NSs gene which encodes the major virulence factor of the virus. The Clone 13 vaccine was previously shown to be safe for young lambs and calves. Moreover, a study in pregnant ewes suggested that the vaccine could also be applied safely during gestation. To anticipate on a possible future incursion of RVFV in Europe, we have evaluated the safety of Clone 13 for young lambs and pregnant ewes. In line with the guidelines from the World Organisation for Animal health (Office International des Epizooties, OIE) and regulations of the European Pharmacopeia (EP), these studies were performed with an overdose. Our studies with lambs showed that Clone 13 dissemination within vaccinated animals is very limited. Moreover, the Clone 13 vaccine virus was not shed nor spread to in-contact sentinels and did not revert to virulence upon animal-to-animal passage. Importantly, a large experiment with pregnant ewes demonstrated that the Clone 13 virus is able to spread to the fetus, resulting in malformations and stillbirths. Altogether, our results suggest that Clone 13 can be applied safely in lambs, but that caution should be taken when Clone 13 is used in pregnant animals, particularly during the first trimester of gestation.</p

Schematic representation of the RTV study.

<p>Two lambs were inoculated via SC and ID routes and blood samples were collected on D0, 1, 2, and 3. On day 7, lambs were euthanized and prescapular lymph nodes were collected. Samples containing the highest amount of Clone 13 RNA were inoculated via the same routes into two naïve lambs (Passage 1). No virus RNA was detected in similar samples collected from these lambs. The passage was repeated with another group of 10 lambs (Repeat passage 1). In none of these lambs, Clone 13 RNA was detected.</p

Inoculation routes and Clone 13 titers used in this study.

<p>Inoculation routes and Clone 13 titers used in this study.</p