Serological and clinical evaluation of the Yugoslavian RM65 sheep pox strain vaccine use in cattle against lumpy skin disease

Humoral immune response profile of a cattle herd vaccinated with 5- and 10-times Bakirköy strain sheep pox vaccine under field conditions

Vaccination is the most effective control measure for Lumpy Skin Disease (LSD). The Bakırköy strain-derived sheep pox vaccine (SPPV) has been used against LSD in Türkiye since 2013. In this study, a cattle herd was vaccinated with SPPV and 35 cattle, of which 9 and 26 received 10 and 5 sheep doses, respectively, were followed for 200 days for humoral immune responses. Additionally, maternal antibodies in colostrum-fed calves were investigated. The humoral immune responses of naive and previously vaccinated cattle were compared to determine the effects of annual re-vaccination. Furthermore, the compatibility of the VNT and ELISA tests was analyzed. According to the results, on day 30 post-vaccination, 19 and 13 out of 35 cattle were positive for VNT and ELISA, respectively. The number of seropositive cattle was higher in the group that had been vaccinated in previous years than in naive cattle. No significant differences were observed in the number of positive cattle between the groups vaccinated with the 5- and 10- doses. In colostrum-fed calves grouped according to age, the seropositivity rate was 87 % (41/47) in the one-week-old group, while this rate was only 18 % (3/16) in the 3-month-old group. It was determined that vaccination at different stages in the last four months of pregnancy did not cause any difference in the number of seropositive calves in one-week-old calves fed with colostrum. The concordance between VNT and ELISA tests was lower in 5-dose vaccinated group than 10-dose vaccinated and colostrum-fed calves groups. This study provides insights into the effect of the vaccination strategy followed by Türkiye during its combat of LSD and revealed that annual repeated vaccination using heterologous vaccine has significant positive effects on humoral immun response at the herd level.

Cracking the Code of Lumpy Skin Disease: Identifying Causes, Symptoms and Treatment Options for Livestock Farmers

The novel bovine viral infection known as lumpy skin disease is common in most African and Middle Eastern countries, with a significant likelihood of disease transfer to Asia and Europe. Recent rapid disease spread in formerly disease-free zones highlights the need of understanding disease limits and distribution mechanisms. Capripox virus, the causal agent, may also cause sheeppox and Goatpox. Even though the virus is expelled through several bodily fluids and excretions, the most common causes of infection include sperm and skin sores. Thus, vulnerable hosts are mostly infected mechanically by hematophagous arthropods such as biting flies, mosquitoes, and ticks. As a result, milk production lowers, abortions, permanent or temporary sterility, hide damage, and mortality occur, contributing to a massive financial loss for countries that raise cattle. These illnesses are economically significant because they affect international trade. The spread of Capripox viruses appears to be spreading because to a lack of effectual vaccinations and poverty in rural areas. Lumpy skin disease has reached historic levels; as a consequence, vaccination remains the only viable option to keep the illness from spreading in endemic as well as newly impacted areas. This study is intended to offer a full update on existing knowledge of the disease's pathological characteristics, mechanisms of spread, transmission, control measures, and available vaccinations.

Evaluation of the safety, immunogenicity and efficacy of a new live-attenuated lumpy skin disease vaccine in India

Lumpy skin disease (LSD) was reported for the first time in India in 2019 and since then, it has become endemic. Since a homologous (LSD-virus based) vaccine was not available in the country, goatpox virus (GPV)-based heterologous vaccine was authorized for mass immunization to induce protection against LSD in cattle. This study describes the evaluation of safety, immunogenicity and efficacy of a new live-attenuated LSD vaccine developed by using an Indian field strain, isolated in 2019 from cattle. The virus was attenuated by continuous passage (P = 50) in Vero cells. The vaccine (50^th LSDV passage in Vero cells, named as Lumpi-ProVac^Ind) did not induce any local or systemic reaction upon its experimental inoculation in calves (n = 10). At day 30 post-vaccination (pv), the vaccinated animals were shown to develop antibody- and cell-mediated immune responses and exhibited complete protection upon virulent LSDV challenge. A minimum Neethling response (0.018% animals; 5 out of 26,940 animals) of the vaccine was observed in the field trials conducted in 26,940 animals. There was no significant reduction in the milk yield in lactating animals (n = 10108), besides there was no abortion or any other reproductive disorder in the pregnant animals (n = 2889). Sero-conversion was observed in 85.18% animals in the field by day 30 pv.

Lumpy skin disease: history, current understanding and research gaps in the context of recent geographic expansion

Lumpy skin disease is recognized as a transboundary and emerging disease of cattle, buffaloes and other wild ruminants. Being initially restricted to Africa, and since 1989 the Middle East, the unprecedented recent spread across Eurasia demonstrates how underestimated and neglected this disease is. The initial identification of the causative agent of LSD as a poxvirus called LSD virus, was well as findings on LSDV transmission and epidemiology were pioneered at Onderstepoort, South Africa, from as early as the 1940s by researchers such as Weiss, Haig and Alexander. As more data emerges from an ever-increasing number of epidemiological studies, previously emphasized research gaps are being revisited and discussed. The currently available knowledge is in agreement with the previously described South African research experience that LSDV transmission can occur by multiple routes, including indirect contact, shared water sources and arthropods. The virus population is prone to molecular evolution, generating novel phylogenetically distinct variants resulting from a diverse range of selective pressures, including recombination between field and homologous vaccine strains in cell culture that produce virulent recombinants which pose diagnostic challenges. Host restriction is not limited to livestock, with certain wild ruminants being susceptible, with unknown consequences for the epidemiology of the disease.

Biological Health Markers Associated with Oxidative Stress in Dairy Cows during Lactation Period

This review aims to summarize and present different biological health markers in dairy cows during the lactation period. Biochemical health markers provide an indicator of how foreign chemical substances, whether external or internal, affect the animal’s health. To understand the relationship between dairy cow health issues and oxidative stress, various biomarkers of oxidative stress must be investigated. Biochemical and hematological factors play a significant role in determining the biological health markers of animals. A variety of biochemical parameters are dependent on various factors, including the animal’s breed, its age, its development, its pregnancy status, and its production status. When assessing the health of cattle, a blood test is conducted to determine the blood chemistry. To diagnose diseases in dairy animals, the blood biochemistry is necessary to determine the cause of many physiological, metabolic, and pathological problems. Observing blood alterations during pregnancy and at peak lactation may determine what factors lift oxidative stress in cows due to disturbances in feed intake and metabolic processes.

The Serological Response in Cattle following Administration of a Heterologous Sheep Pox Virus Strain Vaccine for Protection from Lumpy Skin Disease; Current Situation in Armenia

Lumpy skin disease (LSD) is a highly infectious viral disease of cattle caused by LSD virus (LSDV), which was first reported in Armenia in late 2015. It was identified in pasture-raised cattle near the border with Iran. Currently, vaccination plays a key role in preventing further incursion of disease in high-risk areas. The purpose of this work was to assess the quality of vaccination currently used in Armenia by determining the immune response of the heterologous dry culture sheep pox virus-based vaccine against LSD in cattle. Seroprevalence and seroconversion testing was carried out using an ELISA to detect specific antibodies against LSD before and 30 days after vaccination in three adjacent regions of Armenia (Ararat, Armavir, Gegharkunik). Ixodes ticks were also examined for the presence of LSDV via real-time PCR. We found that the heterologous vaccine used in Armenia creates a high level of population immunity of 86.09% (83.83-87.97%) and no adverse side effects were observed in cattle. Of the 6 types of Ixodes ticks identified and tested, we found no evidence of LSDV circulating in these vectors. These results suggest that regular serological monitoring via ELISA and heterologous vaccination should continue in areas of Armenia at high risk for incursion of LSD to reduce the spread of this highly infectious transboundary disease.

Emergency vaccination of cattle against lumpy skin disease: Evaluation of safety, efficacy, and potency of MEVAC® LSD vaccine containing Neethling strain

Lumpy skin disease (LSD) is an emerging disease of cattle causing significantly high economic losses. Control of LSD depends on the use of homologous attenuated LSD virus strains isolated originally from South Africa (the Neethling strain). The virus belongs to the genus Capripoxvirus, which includes sheep pox virus and goat pox virus. The present study was conducted to evaluate the safety and efficacy of a new live attenuated LSD vaccine produced by Middle East for Vaccines (MEVAC^®) based on the Neethling strain. Tests were performed both in Egypt and Vietnam. Safety was evaluated by inoculation of five cattle with 10 times the recommended dose and observation of the animals for 14 days. Immunogenicity was tested at different periods post-vaccination (PV) in animals receiving the recommended doses of the vaccine using ELISA and virus neutralization test. Five cows were used to determine the protection index (PI) and non-vaccinated control cattle were included. Three calves were challenged by intradermal inoculation of the wild virus (5 × 10⁵ TCID₅₀) 28 days PV. Field or mass vaccination experiments were conducted in Vietnam during national campaigns in the summer of 2021 with 4301 vaccinated animals closely monitored after vaccination. In the field, around 2% (80/4301) of the animals showed hyper-reactivity, and 0.6% (24/4301) showed small skin swellings that disappeared within few hours PV. Abortion was recorded in three animals (0.3% 3/867). Challenged animals were resistant to clinical disease and PI value was 3.5 log₁₀. Meanwhile, antibody levels determined by the ELISA were inconsistent among animals and laboratories during the study period. Overall, the findings point to a new safe and effective LSD vaccine.

The Development of a Real-Time PCR Assay for Specific Detection of the NISKHI Sheep Pox Vaccine Virus Strain DNA

Sheep pox (SPP) constitutes a global animal health scourge, despite the numerous efforts targeting the eradication of the disease implemented in affected countries. An efficient control and eradication strategy incorporates the use of live attenuated vaccines, which in turn requires a method for differentiation between vaccinated and infected sheep. The NISKHI live attenuated SPP vaccine (LAV) is abundantly used in Russia, Kazakhstan and other Central Asian countries. This study describes the development and evaluation of a real-time PCR with a high-resolution melting assay, capable of differentiating the NISKHI vaccine virus from circulating virulent field strains. The RNA polymerase subunit RPO132 gene contains a unique single nucleotide polymorphism (SNP) capable of altering the melting curves of amplicons from LAV and virulent field isolates circulating in the region. The melting temperature (Tm) of field isolates ranged from 75.47 °C ± 0.04 to 75.86 °C ± 0.08, while the vaccine strain averaged 76.46 °C ± 0.12. Subsequent evaluation of this assay demonstrated that the recent SPP outbreaks in central Russia may be attributed to virulent field isolates. This robust assay was proven to consistently and differentially detect the NISKHI LAV strain when analyzing clinical samples from affected sheep.

[Determination of the optimal immunizing dose of heterologous goat pox virus vaccine (Poxviridae: <I>Chordopoxvirinae: Capripoxvirus</I>) against lumpy skin disease]

INTRODUCTION

Lumpy skin disease (LSD), sheep pox and goat pox are dangerous diseases of domestic ruminants. Representatives of the genus of capripoxviruses are antigenically similar and can be used as a vaccine for three infections, as in the case of representatives of the genus of orthopoxviruses, which includes viruses of smallpox, monkeypox, and cowpox, that all belong to a single family Poxviridae.

MATERIALS AND METHODS

In this study, the vaccine strain G20-LKV of the goat pox virus and the virulent strain RIBSP2019/K of the LSD virus were used. The experiments were carried out on clinically healthy cattle of the Kazakh White-headed breed, aged six to eight months. Virological and serological research methods were used in the work.

RESULTS

All immunized animals that received different doses of the vaccine showed resistance to the infection challenge, without showing any clinical signs of the disease. In animals that received the lowest doses of the vaccine 15,000, 30,000 and 40,000 TCID50, no adverse events, skin and temperature reactions were observed at the injection site. Those vaccinated with high doses of the vaccine had a local reaction in the form of swelling at the site of vaccine administration. Control animals infected with a virulent virus showed clinical signs of the cattle lumpy skin disease .

CONCLUSION

The vaccine, prepared based on the "G20-LKV" strain of the goat virus, is protective for cattle against infection with a virulent LSD virus at immunizing doses from 15,000 to 80,000 TCID50, which are dependent on the LSD epizootic situation in particular region.

The complete genome sequence of Indian sheeppox vaccine virus and comparative analysis with other capripoxviruses

Sheeppox virus (SPPV) is responsible for a significant economic loss to sheep husbandry in enzootic regions of Africa, the Middle East, and Asia including the Indian subcontinent. In this study, we present the complete genome sequence of SPPV vaccine strain SPPV-Srin38/00 from India determined by next-generation sequencing (NGS) using Illumina technology. The attenuated Srinagar vaccine strain of SPPV (SPPV-Srin38/00) was developed by serial passaging the virus initially in lamb testes (LT) cells followed by Vero cell line. The SPPV-Srin38/00 virus has a genome size of 150, 103 bp, which encodes for 147 functional putative genes and consists of a central coding region flanked by two identical 2353 bp inverted terminal repeats (ITRs). Comparative phylogenetic analysis based on complete genome sequences of Capripoxviruses formed three distinct groups each for SPPV, GTPV, and LSDV with clustering of SPPV-Srin38/00 strain with SPPV-A strain. Nine ORFs of SPPV-Srin38/00 namely SPPV-Srin_002/SPPV-Srin_155, SPPV-Srin_004/SPPV-Srin_153, SPPV-Srin_009, SPPV-Srin_013, SPPV-Srin_026, SPPV-Srin_132, and SPPV-Srin_136 were found to be fragmented as compared to LSDV, whereas only one ORF (such as SPPV-Srin_136) was found to be fragmented as compared to GTPV. SPPV genomes, including the SPPV-Srin38/00 strain, shared 99.78-99.98% intraspecies nucleotide identity, indicating that SPPV strains have extremely low genetic diversity. The strain shared 96.80-97.08% and 97.11-97.61% nt identity with GTPV and LSDV strains, respectively. Its ORFs 016, 021, 022, 130 and 138 are the least identical ORFs among three species of the genus Capripoxvirus with 72.5-93% aa identity to GTPV and LSDV strains and may be potentially used for differentiation of CaPV species. This study may contribute to a better understanding of the epidemiology and evolution of capripoxviruses as well as the development of specific detection methods, better expression vectors, and vaccines with improved safety and efficacy.

Lumpy skin disease outbreaks in Egypt during 2017-2018 among sheeppox vaccinated cattle: Epidemiological, pathological, and molecular findings

The General Organization of the Veterinary Services in Egypt has adopted a sheeppox vaccination policy to control lumpy skin disease (LSD) in cattle. Over the course of the last two years, recurrent outbreaks were reported, with animals showing severe clinical signs and consequentially higher fatalities than that of cases reported in previous LSD outbreaks. A total of 1050 cattle showing typical clinical signs suggestive of LSD were clinically and pathologically investigated during 2017–2018. Skin nodules were collected and lumpy skin disease virus (LSDV) was screened in collected skin samples using PCR for the RPO-30 gene. Furthermore, the entire P32 protein coding gene was sequenced. Histopathology and immunohistochemistry of the skin nodules were also conducted. The obtained results showed an overall mortality rate of 6.86%. LSDV was confirmed in all the examined nodules as evidenced by immunohistochemistry and positive PCR amplification of the RPO30 gene. Sequencing analysis of the P32 gene revealed a highly conserved nature and genetic stability of the LSDV. The results of the present study show that the current vaccination protocol was not effective for a multitude of reasons. These results also serve as evidence for a strong recommendation of an amendment of homologous vaccine use aside from a complete coverage of cattle populations in order to reduce the incidence of LSD among cattle population in Egypt.

Review: Vaccines and Vaccination against Lumpy Skin Disease

The geographical distribution of lumpy skin disease (LSD), an economically important cattle disease caused by a capripoxvirus, has reached an unprecedented extent. Vaccination is the only way to prevent the spread of the infection in endemic and newly affected regions. Yet, in the event of an outbreak, selection of the best vaccine is a major challenge for veterinary authorities and farmers. Decision makers need sound scientific information to support their decisions and subsequent actions. The available vaccine products vary in terms of quality, efficacy, safety, side effects, and price. The pros and cons of different types of live attenuated and inactivated vaccines, vaccination strategies, and associated risks are discussed. Seroconversion, which typically follows vaccination, places specific demands on the tools and methods used to evaluate the effectiveness of the LSD vaccination campaigns in the field. We aimed to give a comprehensive update on available vaccines and vaccination against LSD, to better prepare affected and at-risk countries to control LSD and ensure the safe trade of cattle.

Emergence and transboundary spread of lumpy skin disease in South Asia

Lumpy skin disease (LSD) is an OIE notifiable, transboundary pox viral disease of livestock. LSD is an emerging disease severely affecting livestock economics. The zoonotic potential of the LSD virus has not been extensively studied and reported. In approximately 90 years, the virus dispersed to numerous world locations after its first emergence in Zambia. LSD virus emergence in South Asia prevailed among livestock (cattle and water buffalo) owners due to economic/financial losses. The estimate of the economic impact of LSD in the southern, eastern and southeastern countries suggested direct losses of livestock and production of approximately USD 1.45 billion. In 2019, nearly the same time, the disease was reported for the first time from many bordering countries, such as India, Nepal, China, and Bangladesh. In 2020, the LSD was also recorded in Bhutan, Sri Lanka, Bangladesh, Vietnam and Southeast China. In 2021, it further spread to new countries such as Thailand, Malaysia and Cambodia. Cattle affected with LSD show a characteristic nodular lesion or skin lump over the whole body and may occasionally be associated with systemic signs. Hematophagous arthropod-borne mechanical transmission is considered primary and the most common route; however, other transmission routes related to illegal animal trade have played a role in the emergence of LSD in countries otherwise/earlier free from it. Among serological diagnostic tests, OIE recommends virus neutralization as the standard gold test. Diagnosis in LSD-free countries requires virus isolation and further sequencing of the isolate. Control of LSD is possible by most of the measures applied for rapidly transmitting viral infection, including vaccination. LSD virus-specific vaccines are considered suitable to confer protection to cattle and buffalo over heterologous vaccines. In countries such as India, the lack of a specific policy for LSD at the time of the first onset of this disease, the high density of susceptible unvaccinated populations, unawareness among farmers, veterinarians and prevailing laws of no slaughter of cattle created a favourable situation of its spread to many states. Amid COVID-19, the whole world is in turmoil; the emergence of diseases such as LSD is further lowering the economy, and hence must be reviewed to save and sustain the backbone of the developing country's economy in Southeast Asia.

Molecular characterization and phylogenetic analysis of lumpy skin disease in Egypt

Lumpy skin disease (LSD) is an infectious viral disease affecting cattle, cause severe economic losses. In the last few years, the disease is widely distributed in many countries in the Middle East, including Egypt. This study aimed to determine the genetic character of LSDV circulating in some governorates in Egypt and its relation with other LSDVs and vaccine strains in GenBank. A total of 50 skin nodules and 50 blood samples were collected from clinically affected cattle to detect LSDV using PCR targeting the P32 gene. The positive samples were characterized using PCR targeting the GPCR gene. The amplified products of four samples detected in the skin nodule of cattle from Alexandria and Kafr ElSheikh governorates were sequenced, and the phylogenetic tree was constructed. Out of 100 analyzed samples, 70 samples were positive for LSDV by PCR assay. In addition, the sequence alignment of the obtained LSDV strains detected in the Alexandria governorate showed high similarity to the LSDV genome (MN995838). In contrast, LSDV strains from Kafr ElSheikh governorate revealed high similarity and the previous Egyptian strain (MG970343), which was isolated from cattle in Sharkia governorate in 2016. Also, the phylogenetic analysis confirmed that one of the LSDV strain (LC601598) from Alexandria is closely related to the LSDV of Menofia/Egypt/2019 (MN271722), while another one (LC601597) is closely related to vaccine strains of LSDV. Moreover, the LSDV strains from Kafr Elsheikh showed closely related to previous LSDV strains isolated from Menofia (MG970343) and Dakahlia (KP071936) governorates and clustered with other LSDV strains in a distinct cluster. This information is for understanding the epidemiology of LSDV and supporting the establishment of an efficient control program for the disease.

Investigation of Post Vaccination Reactions of Two Live Attenuated Vaccines against Lumpy Skin Disease of Cattle

Lumpy skin disease virus (LSDV) causes an economically important disease in cattle. The only method for successful control is early diagnosis and efficient vaccination. Adverse effects of vaccination such as local inflammation at the injection site and localized or generalized skin lesions in some vaccinated animals have been reported with live vaccines. The aim of this work was to compare the safety of two lumpy skin disease (LSD) vaccine strains, Kenyan (Kn) Sheep and Goat Pox (KSGP O-240) and LSDV Neethling (Nt) strain, and to determine the etiology of the post-vaccination (pv) reactions observed in cattle. Experimental cattle were vaccinated under controlled conditions with Nt- and KSGP O-240-based vaccines, using two different doses, and animals were observed for 3 months for any adverse reactions. Three out of 45 cattle vaccinated with LSDV Nt strain (6.7%) and three out of 24 cattle vaccinated with Kn strain (12.5%) presented LSD-like skin nodules, providing evidence that the post-vaccination lesions may not be strain-dependent. Lesions appeared 1–3 weeks after vaccination and were localized in the neck or covering the whole body. Animals recovered after 3 weeks. There is a positive correlation between the vaccine dose and the appearance of skin lesions in vaccinated animals; at the 105 dose, 12% of the animals reacted versus 3.7% at the 104 dose. Both strains induced solid immunity when protection was measured by neutralizing antibody seroconversion.

Isolation and characterization of lumpy skin disease virus from cattle in India

Lumpy skin disease (LSD) has devastating economic impact. During the last decade, LSD had spread to climatically new and previously disease-free countries, which also includes its recent emergence in the Indian subcontinent (2019). This study deals with the LSD outbreak(s) from cattle in Ranchi (India). Virus was isolated from the scabs (skin lesions) in the primary goat kidney cells. Phylogenetic analysis based on nucleotide sequencing of LSD virus (LSDV) ORF011, ORF012 and ORF036 suggested that the isolated virus (LSDV/Bos taurus-tc/India/2019/Ranchi) is closely related to Kenyan LSDV strains. Further, we adapted the isolated virus in Vero cells. Infection of the isolated LSDV to Vero cells did not produce cytopathic effect (CPE) until the 4^th blind passage, but upon adaptation, it produced high viral titres in the cultured cells. The kinetics of viral DNA synthesis and one-step growth curve analysis suggested that Vero cell-adapted LSDV initiates synthesizing its genome at ~24 hours post-infection (hpi) with a peak level at ~96 hpi whereas evidence of progeny virus particles was observed at 36–48 hours (h) with a peak titre at ~120 h. To the best of our knowledge, this study describes the first successful isolation of LSDV in India, besides providing insights into the life cycle Vero cell-adapted LSDV.

Experimental evaluation of the cross-protection between Sheeppox and bovine Lumpy skin vaccines

The Capripoxvirus genus includes three agents: Sheeppox virus, Goatpox virus and Lumpy skin disease virus. Related diseases are of economic importance and present a major constraint to animals and animal products trade in addition to mortality and morbidity. Attenuated vaccines against these diseases are available, but afforded cross-protection is controversial in each specie. In this study, groups of sheep, goats and cattle were vaccinated with Romania SPPV vaccine and challenged with corresponding virulent strains. Sheep and cattle were also vaccinated with Neethling LSDV vaccine and challenged with both virulent SPPV and LSDV strains. Animals were monitored by clinical observation, rectal temperature as well as serological response. The study showed that sheep and goats vaccinated with Romania SPPV vaccine were fully protected against challenge with virulent SPPV and GTPV strains, respectively. However, small ruminants vaccinated with LSDV Neethling vaccine showed only partial protection against challenge with virulent SPPV strain. Cattle showed also only partial protection when vaccinated with Romania SPPV and were fully protected with Neethling LSDV vaccine. This study showed that SPPV and GTPV vaccines are closely related with cross-protection, while LSDV protects only cattle against the corresponding disease, which suggests that vaccination against LSDV should be carried out with homologous strain.

Goatpox virus (G20-LKV) vaccine strain elicits a protective response in cattle against lumpy skin disease at challenge with lumpy skin disease virulent field strain in a comparative study

In this comparative study, we examine the safety of the sheeppox (SPP) and goatpox (GTP) vaccines and the protective response of these vaccines in cattle against a virulent lumpy skin disease (LSD) field strain. The vaccine safety was tested in rabbits, mice and cattle using ten times recommended dose. In the safety trial, none of the vaccinated animals showed any deviation from physiological norms or fever, inappetence or local/ generalized skin reactions. In the challenge trial, both SPP and GTP vaccine groups developed virus-neutralizing antibodies with an average titre of 2.1 log₂ at 21 days post-vaccination. No significant difference in seroconversion was found in cattle vaccinated with SPP and GTP vaccines (P ≥ 0.05). When challenged with a virulent LSD field strain, one animal vaccinated with the SPP Niskhi vaccine strain showed typical LSD skin lesions at the injection sites of different dilutions of the challenge virus. All animals vaccinated with GTP G20-LKV vaccine strain showed full protection. After infection with the challenge virus, unvaccinated fully susceptible control cattle showed characteristic clinical signs of LSD. The average protective index for SPP and GTP vaccine groups was 5.3 ± 1.42 and 5.9 ± 0.00, respectively.

Lumpy skin disease epidemiological report IV: data collection and analysis

In 2019, no lumpy skin disease (LSD) outbreaks were reported in South-Eastern Europe, the mass vaccination regional campaign with homologous LSD vaccine continued for the fourth year with over 1.8 million bovines vaccinated in the region, preventing further outbreaks since 2016. LSD outbreaks were reported in Turkey, including western Turkey, in Russia and in eastern Asia affecting China, Bangladesh and India for the first time. The use of homologous vaccine should be considered in the countries still affected in order to eliminate the virus. Besides passive surveillance, which is implemented in all the countries, active surveillance for early detection based on clinical examination could be conducted ideally during April-October every 5 weeks in at-risk areas, based on possible re-emergence or re-introduction from affected neighbouring countries. Active surveillance for proving disease freedom could be based on serological testing (enzyme-linked immunosorbent assay (ELISA)) targeting 3.5% seroprevalence and conducted on a random sample of cattle herds on non-vaccinated animals. LSD re-emerged in Israel in 2019, after vaccination became voluntary. This shows that, if the virus is still circulating in the region, the reduced protection might result in re-emergence of LSD. In case of re-emergence, a contingency plan and vaccine stockpiling would be needed, in order to react quickly. From a study performed in Israel to test side effects of live-attenuated homologous LSD vaccine, milk production can be reduced during 7 days after vaccination (around 6-8 kg per cow), without a significant loss in the 30 days after vaccination. Research needs should be focused on the probability of transmission from insect to bovine, the virus inactivation rate in insects, the collection of baseline entomological data, the capacity of vector species in LSDV transmission linked to studies on their abundance and the control of Stomoxys calcitrans being the most important vector in LSD transmission.

Lumpy skin disease: III. Data collection and analysis

In 2018, no lumpy skin disease (LSD) outbreaks were reported in the Balkan region, after the decline reported in 2017 (385) compared to 2016 (7,483). This confirms the effectiveness of the vaccination campaign based on the LSD homologous vaccine strain which continued throughout 2018 with over 2.5 million animals vaccinated, keeping the mean vaccination coverage above 70%. In 2018, LSD outbreaks were reported in Russia, Turkey and Georgia. In Russia, the LSD epidemics expanded northward and eastward, while in Turkey, the most affected region was in the east. LSD is spreading in Turkey since 2013, despite large vaccination campaigns with heterologous vaccine performed since 2014. This might support the hypothesis that the use of heterologous vaccines results in insufficient protection, and therefore, the use of homologous LSD vaccine in Turkey should be considered to prevent further spread. As the LSD epidemic in Turkey is a risk for reintroduction into the EU, it is recommended to continue the vaccination campaigns in 2019 in the high‐risk areas of Balkan region. Spread rates of LSD within a village were estimated from outbreak data for Albania, which can be used to inform the level of vaccination required to control an outbreak in a village. In terms of vaccine safety, the reports from the field suggest that, compared to the large number of animals vaccinated in the Balkan region since 2015, a very limited number of side effects have been recorded so far, although from published literature, local or even systemic side effects in some animals may occur after vaccination. However, due to inadequate study design in the reviewed studies, there is no consensus on the magnitude of such effects and on their real consequences on production.