Schmallenberg Virus: To Vaccinate, or Not to Vaccinate?

Abstract

Schmallenberg virus (SBV), a teratogenic orthobunyavirus that infects predominantly ruminants, emerged in 2011 in Central Europe, spread rapidly throughout the continent, and subsequently established an endemic status with re-circulations to a larger extent every 2 to 3 years. Hence, it represents a constant threat to the continent’s ruminant population when no effective countermeasures are implemented. Here, we discuss potential preventive measures to protect from Schmallenberg disease. Previous experiences with other arboviruses like bluetongue virus have already demonstrated that vaccination of livestock against a vector-transmitted disease can play a major role in reducing or even stopping virus circulation. For SBV, specific inactivated whole-virus vaccines have been developed and marketing authorizations were granted for such preparations. In addition, candidate marker vaccines either as live attenuated, DNA-mediated, subunit or live-vectored preparations have been developed, but none of these DIVA-capable candidate vaccines are currently commercially available. At the moment, the licensed inactivated vaccines are used only to a very limited extent. The high seroprevalence rates induced in years of virus re-occurrence to a larger extent, the wave-like and sometimes hard to predict circulation pattern of SBV, and the expenditures of time and costs for the vaccinations presumably impact on the willingness to vaccinate. However, one should bear in mind that the consequence of seronegative young animals and regular renewed virus circulation might be again more cases of fetal malformation caused by an infection of naïve dams during one of their first gestations. Therefore, an appropriate and cost-effective strategy might be to vaccinate naïve female animals of all affected species before the reproductive age.

Identification and Genetic Characterization of Viral Pathogens in Ruminant Gestation Abnormalities, Israel, 2015–2019

“…The prevention of infections with simbuviruses or BTV and, along with it, the prevention of clinical disease, abortion, fetal malformation or potential reassortment events is complicated by the transmission mode, as insect-transmitted viruses are harder to control by means other than vaccination than are pathogens directly transmitted from animal to animal. As an example, European experiences during the BTV-8 outbreak in 2006/2007 have demonstrated that vaccination can play a major role in reducing virus circulation or even in eradicating a vector-transmitted disease from a given region [66,67], while SBV, for which no vaccination campaign is in place, is endemic in Central Europe since its initial emergence about 10 years ago [61,68]. In contrast, BVDV has been successfully eradicated from several countries without vaccination after the implementation of control programs that are based on systematic control, the identification and rapid removal of infected animals, movement restrictions and further biosecurity measures [69,70].…”

Schmallenberg disease: literature review and epizootic situation in the world and in Russia

“…Для предотвращения новых вспышек и снижения риска возникновения новых очагов инфекции может применяться вакцинация всего восприимчивого поголовья. Более рентабельной стратегией может быть вакцинация самок животных всех восприимчивых видов до наступления репродуктивного возраста [45].…”

Biophysical and structural study of La Crosse virus endonuclease inhibition for the development of new antiviral options

“…La Crosse virus (LACV) is the most common neuroinvasive arboviral infection in children (Boutzoukas et al, 2023) in the United States (Vahey et al, 2021) and serves as a study model for other neuroinvasive orthobunyaviruses such as Jamestown Canyon orthobunyavirus (JCV) and Snowshoe hare orthobunyavirus (SSHV) in the USA and Canada (Evans & Peterson, 2021), Tahyna orthobunyavirus (TAHV), which is widely distributed throughout Europe, Africa and Asia, and Inkoo orthobunyavirus (INKV), which is found in Scandinavia (Lwande et al, 2017;Vapalahti et al, 1996). Other animal-infecting orthobunyaviruses include Schmallenberg virus (SBV) and Akabane virus, which severely affect ruminants (Wernike & Beer, 2017;Yanase et al, 2020). Reports of the newly identified Cristoli orthobunyavirus and the emergence of Umbre orthobunyavirus as agents responsible for fatal encephalitis (Rodriguez et al, 2020;Pe ´rot et al, 2021) stress the importance and necesssity of monitoring the impact of orthobunyaviruses on human health and activities.…”