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Lumpy skin disease (LSD), caused by the lumpy skin disease virus of the genus Capripoxvirus, is rapidly emerging across most countries in Asia. Recently, LSD has been linked to very high morbidity and mortality rates. Until 2019, India remained free of LSD, resulting in a lack of locally developed diagnostic kits, biologicals, and other tools necessary for managing the disease in a country with such a large livestock population. Therefore, this study aimed to design and validate an indigenous and cost-effective in-house ELISA for large-scale screening of cattle samples for antibodies to LSDV. The viral major open reading frames ORF 095 and ORF 103 encoding virion core proteins were expressed in a prokaryotic system and the recombinant antigen cocktail was used for optimization and validation of an indirect ELISA (iELISA). The calculated relative diagnostic sensitivity and diagnostic specificity of the iELISA were 96.6 % and 95.1 %, respectively at the cut-off percent positivity (PP≥50 %). The in-house designed double-antigen iELISA was found effective to investigate the seroprevalence of LSDV in various geographical regions of India., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Since 2019, Lumpy skin disease (LSD) has suddenly spread in many Asian countries, including India. LSD primarily occurs in cattle. However, recent LSD outbreaks in India have also revealed significant morbidity and production losses in buffaloes. This has raised concerns about the role of buffaloes in the epidemiology and transmission of LSD and necessitates the inclusion of buffaloes in the mass vaccination program for the prevention and control of the disease in the country. However, there is no significant data on the immune response in buffaloes following vaccination with the LSD vaccine. In this study, we evaluated antibody- and cell-mediated immune responses following vaccination with a newly developed live-attenuated LSD vaccine (Lumpi-ProVac Ind ). The detectable amount of anti-LSDV antibodies was observed at 1-2 months following vaccination, with a peak antibody titer at 3 months. Upon stimulation of the peripheral blood mononuclear cells (PBMCs) with the UV-inactivated LSDV antigen, there was a significant increase in CD8 + T cell counts in vaccinated animals as compared to the unvaccinated animals. Besides, vaccinated animals also showed a significant increase in IFN-γ levels upon antigenic stimulation of their PBMCs with LSDV antigen. In conclusion, the buffaloes also mount a potent antibody- and cell-mediated immune response following vaccination with Lumpi-ProVac Ind ., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

To implement effective lumpy skin disease (LSD) control measures, such as timely vaccination, particularly in calves and serological monitoring, it is necessary to evaluate immune response after vaccination, both in adult cattle and in their calves. The aim of this study was to evaluate passive immunity transfer and duration of maternal antibodies against lumpy skin disease virus (LSDV) in calves born to vaccinated cows by two different serological methods. The longitudinal study was carried out on two farms in Serbia where no cases were reported during LSD outbreak in 2016. Fifteen cows on each farm were vaccinated and revaccinated with attenuated vaccine - Neethling strain. A total of 30 cows and 30 calves on both farms were included in the study. Serum samples from cows were collected on calving day and serum samples from their respective calves on days 10, 20, 30, 45, 60, 75, 90, 105 and 120 after birth. Colostrum samples were collected only from 15 cows on one farm. In order to determine the presence of antibodies against LSDV a total of 30 cow sera samples, 15 colostrum samples and 270 calf sera samples were examined by commercial enzyme-linked immunosorbent assay (ELISA) and modified virus neutralization test (VNT). Overall, the performance of both serological tests was very satisfactory. The results of this longitudinal study showed that persistence of passive immunity in calves is less than 4 months, and that most calves are not protected against LSDV at that age. Since the vaccination is the most important control measure against LSDV, the recommended age of six months for vaccination of calves born to vaccinated cows should be reassessed to achieve the most optimal protection against LSD., (© 2024. The Author(s).)

Poxviruses gained international attention due to the sharp rise in monkeypox cases in recent years, highlighting the urgent need for the development of a secure and reliable vaccine. This study involved the development of an innovative combined subunit vaccine (CSV) targeting poxviruses, with lumpy skin disease virus (LSDV) serving as the model virus. To this end, the potential sites for poxvirus vaccines were fully evaluated to develop and purify four recombinant proteins. These proteins were then successfully delivered to the dermis in a mouse model by utilizing dissolvable microneedle patches (DMPs). This approach simplified the vaccination procedure and significantly mitigated the associated risk. CSV-loaded DMPs contained four recombinant proteins and a novel adjuvant, CpG, which allowed DMPs to elicit the same intensity of humoral and cellular immunity as subcutaneous injection. Following immunization with SC and DMP, the mice exhibited notable levels of neutralizing antibodies, albeit at a low concentration. It is noteworthy that the CSV loaded into DMPs remained stable for at least 4 months at room temperature, effectively addressing the storage and transportation challenges. Based on the study findings, CSV-loaded DMPs are expected to be utilized worldwide as an innovative technique for poxvirus inoculation, especially in underdeveloped regions. This novel strategy is crucial for the development of future poxvirus vaccines., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Sheeppox virus (SPPV), goatpox virus (GTPV), and lumpy skin disease virus (LSDV) are the three members of the genus Capripoxvirus within the Poxviridae family and are the etiologic agents of sheeppox (SPP), goatpox (GTP), and lumpy skin disease (LSD), respectively. LSD, GTP, and SPP are endemic in Africa and Asia, causing severe disease outbreaks with significant economic losses in livestock. Incursions of SPP and LSD have occurred in Europe. Vaccination with live attenuated homologous and heterologous viruses are routinely implemented to control these diseases. Using the gold standard virus neutralization test, we studied the ability of homologous and heterologous sera to neutralize the SPPV and LSDV. We found that LSD and SPP sera effectively neutralize their homologous viruses, and GTP sera can neutralize SPPV. However, while LSD sera effectively neutralizes SPPV, SPP and GTP sera cannot neutralize the LSDV to the same extent. We discuss the implications of these observations in disease assay methodology and heterologous vaccine efficacy.

Mycoplasma mycoides subsp. mycoides (Mmm) is the causative agent of contagious bovine pleuropneumonia (CBPP). Lumpy skin disease (LSD) is a viral disease of cattle caused by lumpy skin disease virus (LSDV). LSD and CBPP are both transboundary diseases spreading in the same areas of Africa and Asia. A combination vaccine to control CBPP and LSD offers significant value to small-scale livestock keepers as a single administration. Access to a bivalent vaccine may improve vaccination rates for both pathogens. In the present study, we evaluated the LSDV/CBPP live combined vaccine by testing the generation of virus neutralizing antibodies, immunogenicity, and safety on target species. In-vitro assessment of the Mycoplasma effect on LSDV growth in cell culture was evaluated by infectious virus titration and qPCR during 3 serial passages, whereas in-vivo interference was assessed through the antibody response to vaccination. This combined Mmm/LSDV vaccine could be used to protect cattle against both diseases with a single vaccination in the endemic countries. There were no adverse reactions detected in this study and inoculated cattle produced high levels of specific antibodies starting from day 7 post-vaccination, suggesting that this combination vaccine is both safe and effective.

Lumpy Skin Disease (LSD) and Bluetongue (BT) are the main ruminants viral vector-borne diseases. LSD is endemic in Africa and has recently emerged in Europe and central Asia as a major threat to cattle industry. BT caused great economic damage in Europe during the last decade with a continuous spread to other countries. To control these diseases, vaccination is the only economically viable tool. For LSD, only live-attenuated vaccines (LAVs) are commercially available, whilst for BT both LAVs and inactivated vaccines are available with a limited number of serotypes. In this study, we developed an inactivated, oil adjuvanted bivalent vaccine against both diseases based on LSDV Neethling strain and BTV4. The vaccine was tested for safety and immunogenicity on cattle during a one-year period. Post-vaccination monitoring was carried out by VNT and ELISA. The vaccine was completely safe and elicited high neutralizing antibodies starting from the first week following the second injection up to one year. Furthermore, a significant correlation (R = 0.9040) was observed when comparing VNT and competitive ELISA in BTV4 serological response. Following BTV4 challenge, none of vaccinated and unvaccinated cattle were registered clinical signs, however vaccinated cattle showed full protection from viraemia. In summary, this study highlights the effectiveness of this combined vaccine as a promising solution for both LSD and BT control. It also puts an emphasis on the need for the development of other multivalent inactivated vaccines, which could be greatly beneficial for improving vaccination coverage in endemic countries and prophylaxis of vector-borne diseases., (Copyright © 2021. Published by Elsevier B.V.)

Despite the wide use of the live attenuated Neethling lumpy skin disease (LSD) vaccine, only limited data existed on its efficacy and effectiveness prior to the large LSD epidemic in the Balkans, which took place during 2016-2017. In addition, analysis of risk factors for the disease was hardly performed with proper control for vaccination effects and potential differences in exposure to the virus. Data from the LSD epidemics in six Balkan countries (Bulgaria, Greece, Serbia, Montenegro, Former Yugoslav Republic of Macedonia (FYROM) and Albania) affected during 2016 were analyzed to determine vaccine effectiveness (VE) and risk factors for LSD infection at the farm level. Vaccination was performed along the occurrence of the epidemics and thus vaccination status of some of the farms changed during the epidemic. To allow for this, left truncated and right censored survival analysis was used in a mixed effects Cox proportional hazard regression model to calculate VE and risk factors for LSD. The results indicated of an average VE of 79.8% (95% CI: 73.2-84.7)) in the six countries, with the lowest VE of 62.5% documented in Albania and up to VE of more than 97% as documented in Bulgaria and Serbia. Analysis of time from vaccination to development of protective immunity showed that VE mostly developed during the first 14 days after vaccination. Data from Greece showed that the vaccination adjusted hazard ratio for LSD was 5.7 higher in grazing farms compared to non-grazing farms. However, due to a difference in geographical location of grazing and non-grazing farms and higher vaccination rate in non-grazing farms, this effect can be at least partly attributed to indirect protection due to herd immunity provided by surrounding vaccinated farms., (Copyright © 2018. Published by Elsevier B.V.)

Lumpy skin disease (LSD) of cattle is caused by a virus within Capripoxvirus genus. It leads to huge economic losses in addition to trade and animal movement limitation. Vaccination is the only economically feasible way to control this vector-borne disease. Only live attenuated vaccines have been used so far and no inactivated vaccine has been developed nor tested in cattle. In this study, we developed an inactivated oily adjuvanted vaccine based on Neethling strain and tested it on cattle. Selected criteria of appreciation were safety, antibody response by Virus Neutralization and protection through challenge. A field trial was also performed in Bulgaria. The vaccine was safe and did not cause any adverse reaction, high level of specific antibodies was obtained starting from day 7 post-vaccination and protection against virulent challenge strain that caused typical disease in control animals was total. Induced protection was similar to that obtained with live vaccine, without any adverse effect. In addition, the field study confirmed safety and efficacy of the vaccine, which did not show any adverse reaction and induced a high level of antibodies for up to one year. General prophylaxis based on inactivated vaccine could be of great benefit in endemic countries or at risk regions., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Lumpy skin disease virus (LSDV), a Capripoxvirus, is of economic importance in the cattle industry and is controlled by vaccination. A comparison was made of the host response to the two LSDV vaccines Neethling and Herbivac LS, with reference to the well-studied Orthopoxvirus, modified vaccinia Ankara (MVA), in a mouse model. Because the vaccines differ at the superoxide dismutase homologue (SOD) gene locus, recombinant SOD knock-out and knock-in nLSDV vaccines were constructed and all four vaccines were tested for the induction and inhibition of apoptosis. The SOD homologue was associated both with induction of apoptosis as well as inhibition of camptothecin-induced apoptosis. Histological analysis of chorioallantoic membranes of fertilized hens' eggs infected with the four different vaccines indicated marked mesodermal proliferation associated with vaccines containing the full-length SOD homologue as well as increased immune cell infiltration. Our findings suggest that the SOD homologue may influence vaccine immunogenicity.

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 log 2 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., Competing Interests: Declaration of Competing Interest The author(s) declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In this paper, we report the resurgence of lumpy skin disease (LSD) in Kurgan Oblast, Russia, in 2018. The majority of the outbreaks were silent with no mortality and congregated within an area with a radius of about 30 km located 1-50 km away from the national border with Kazakhstan. Following primary molecular diagnosis, LSD virus (LSDV) isolates were analyzed using a panel of PCR assays targeting different genetic loci, namely, LSD008 (vaccine), LSDV126 (field), and GPCR (vaccine and field), for differentiation and genotype assignment. All isolates were positive for the vaccine genotype of GPCR and negative for the other field targets tested. A PCR assay with melt curve analysis utilizing LSD008, developed in this work, indicated that the strains melted with a profile similar to those of field strains. Surprisingly, sequence analysis of the RPO30 and GPCR genes aligned the Kurgan/2018 isolate with KSGP O-240 at the GPCR locus, but with Saratov/2017 at the RPO30 locus. The latter cluster forms an association with a sub-cluster of the field strains comprising the South African KSGP O-240 strain and NI-2490 strain. Due to these incongruent phylogenetic patterns, the sequences of three additional loci ORF19 (Kelch-like protein), ORF52 (putative transcriptional elongation factor), and ORF87 (mutT motif protein) were investigated. Phylogenetic analysis of these additional loci placed the strain Kurgan/2018 in either vaccine or field groups, strongly suggesting a novel recombinant profile. This is another piece of evidence exposing the potential for recombination in capripoxviruses and the ignored danger of using live homologous vaccines against LSD. The necessity to revise the PCR-based strategy differentiating infected from vaccinated animals is discussed. The potential scenarios of incursion and the contribution of the KSGP/NI-2490-like strain to the emergence of the recently identified vaccine-like recombinant are discussed.

The transmission of "lumpy skin disease virus" (LSDV) has prompted intensive research efforts due to the rapid spread and high impact of the disease in recent years, especially in Eastern Europe and Balkan countries. In this study, we experimentally evaluate the vaccine-derived virulent recombinant LSDV strain (Saratov/2017) and provide solid evidence on the capacity of the virus for transmission in a vector-proof environment. In the 60-day long experiment, we used inoculated bulls (IN group) and two groups of in-contact animals (C1 and C2), with the former (C1) being in contact with the inoculated animals at the onset of the trial and the latter (C2) being introduced at day 33 of the experiment. The infection in both groups of contact animals was confirmed clinically, serologically and virologically, and viremia was demonstrated in blood, nasal and ocular excretions, using molecular tools. Further studies into LSDV biology are a priority to gain insights into whether the hypothesized indirect contact mode evidenced in this study is a de novo-created feature, absent from both parental stains of the novel (recombinant) LSDV isolate used, or whether it was dormant, but then unlocked by the process of genetic recombination. Author summary: In global terms, LSD has been termed a "neglected disease" due to its historic natural occurrence of being restricted to Africa and, occasionally, Israel. However, after its slow spread throughout the Middle East, the disease is now experiencing a resurgence of research interest following a recent and rapid spread into more northern latitudes. Given the dearth of solid findings on potential transmission mechanisms, no efficient or reliable control program currently exists, which does not involve the use of live attenuated vaccines or stamping out policies - both of which are controversial for implementation in non-endemic regions or countries. The vector-borne mode is the only working concept currently available, but with scarce evidence to support the aggressive spread northwards - except for human-assisted spread, including legal or illegal animal transportation. The emergence of outbreaks is not consistently linked to weather conditions, with the potential for new outbreaks to occur and spread rapidly. Here, for the first time, we provide evidence for indirect contact-mode transmission for a naturally-occurring recombinant LSDV isolated from the field. In an insect-proof facility, we obtained solid evidence that the novel LSDV strain can pass to in-contact animals. Given the recombinant nature of the virus utilised, its genetic background relating to the observed transmission pattern within the study needs to be delineated.

During this study a new Immunoperoxidase Monolayer Assay (IPMA) was developed for the detection of antibodies against lumpy skin disease virus (LSDV) in an easy and low tech setting. Using two dilutions (1:50 and 1:300) in a duplicate format, the test was shown to be highly sensitive, specific and repeatable. In comparison to the VNT and a commercial ELISA, the LSDV-IPMA was able to detect the LSDV antibodies earlier in infected, vaccinated and vaccinated/infected animals. The assay is very flexible as it can be easily adapted for the detection of sheeppox or goatpox antibodies and it can be scaled-up to handle medium size sample sets by preparing the IPMA plates in advance. These plates are safe and can be handled in low biosafety level labs., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)

Lumpy skin disease virus (LSDV) infections can cause massive clinical signs in cattle and have great economic impact due to severe trade restrictions. For LSDV control, only live attenuated vaccines are commercially available, but they currently are not authorized in the European Union. Moreover, these vaccine virus strains can induce substantial side effects with clinical signs similar to infections with virulent LSDV. In our study, we compared clinical symptoms, viremia, and seroconversion of cattle inoculated either with a virulent field strain from North Macedonia isolated from diseased cattle in 2016 or with the attenuated LSDV vaccine strain "Neethling". Using specimens from the field and from experimental inoculation, different diagnostic tools, including a pan-capripox real-time qPCR, newly developed duplex real-time qPCR assays for differentiation between virulent and attenuated LSDV strains, and several serological methods (ELISA, indirect immunofluorescence test and serum neutralization test [SNT]) were evaluated. Our data show a high analytical sensitivity of both tested duplex real-time qPCR systems for the reliable distinction of LSDV field and vaccine strains. Moreover, the commercially available capripox double-antigen ELISA seems to be as specific as the SNT and therefore provides an excellent tool for rapid and simple serological examination of LSDV-vaccinated or infected cattle.

Examination of lumpy skin disease virus (LSDV) isolates from different geographic regions and times revealed that assays developed in our laboratory for differentiating between virulent Israeli viruses and Neethling vaccine virus (NVV) are generally useful in most, if not all, endemic areas in which NVV-based vaccines are used. Recently it was revealed that the LSDV126 gene of field isolates contains a duplicated region of 27 bp (9 aa), while the vaccine viruses have only one copy. Phylogenetic analysis of a 532-bp segment carrying the LSDV126 gene and whole virus genome sequences revealed that LSDV isolates formed two groups: virulent and vaccine viruses. In this analysis, all of the capripox viruses that lack the ability to efficiently infect cattle were found to carry only one copy of the 27-bp fragment, suggesting that the LSDV126 gene plays an important role in the ability of capripox viruses to infect cattle. In silico analysis of potential antigenic sites in LSDV126 revealed that LSDV126 variants with only one copy of the repeat lack a potentially important antigenic epitope, supporting its possible significance in cattle infection. This study provides new information about the nature of the LSDV126 gene and its possible role in the life cycle of LSDV.

Lumpy skin disease (LSD) has affected many regions of Russia since its first occurrence in 2015. The most devastating year for Russia was 2016, when the virus resurged following a modified stamping-out campaign, causing 313 outbreaks in 16 regions. To avoid unwanted adverse reactions following the use of live attenuated vaccines against LSD virus (LSDV), sheeppox-based vaccines were administered during vaccination campaigns. As a result, LSD was successfully contained in all Russian regions in 2017. In the same year, however, LSD emerged anew in a few regions of the Privolzhsky Federal District of Russia along the northern border of Kazakhstan, which then necessitated vaccinating cattle with a live attenuated LSDV vaccine. Although live attenuated LSDV vaccines are prohibited in Russia, several vaccine-like LSDV strains were identified in the 2017 outbreaks, including commercial farms and backyard animals exhibiting clinical signs consistent with those of field LSDV strains. Sequence alignments of three vaccine-like LSDV strains showed clear similarity to the corresponding RPO30 and GPCR gene sequences of commercial attenuated viruses. How vaccine-like strains spread into Russian cattle remains to be clarified.

Background: In the presented study we investigated the development of the humoral immune response against LSDV during the process of re-vaccination of cattle over a time span of 5 months. In addition, the performance of different serological techniques for antibody detection against LSDV was compared. For sample collection, an area without previous LSD outbreak reports in Serbia was selected. Seventy-nine cattle from twenty farms vaccinated in 2016 and re-vaccinated in 2017 were included in the study. Two farms from the same area with good calving management were selected for investigation of passive LSDV antibody transfer from vaccinated mothers to new-borne calves., Results: All investigated cattle were healthy on the day of vaccination and during the whole study. Swelling at the injection site or other side effects of vaccination did not occur after re-vaccination in the study. Detection of LSD-specific antibodies was performed with the standard serological methods VNT and IFAT as well as a commercially available Capripox double antigen multi-species-ELISA. Capripoxvirus-specific antibodies were detected 46 to 47 weeks after vaccination in 2016, with VNT in 35.06% and with IFAT and ELISA in 33.77%. A secondary response was observed in all three tests 1 month after re-vaccination with a significant increase in seropositive animals compared to the results before re-vaccination. With all applied serological methods, the number of animals testing positive was significantly higher at 1 and 5 months post re-vaccination than before re-vaccination. No significant statistical difference (p > 0.05) was observed between the results of all three tests used. The sensitivity and specificity of ELISA was estimated to be Se ELISA 91% and Sp ELISA 87% calculated by the results of VNT and Se ELISA 88% and Sp ELISA 76% calculated by the results of IFAT. Passive antibody transfer from vaccinated mothers to new-born calves was investigated at 14 days after birth. Discrepancies for the detection of LSDV specific antibodies between cows and newborn calves at the age of 14 days were observed in VNT and IFAT, but not in ELISA., Conclusion: Of all tests used the commercially available ELISA shows to be the most useful for high throughput analysis compared to VNT or IFAT.

A simple method to estimate the size of the vaccine bank needed to control an epidemic of an exotic infectious disease in case of introduction into a country is presented. The method was applied to the case of a Lumpy Skin disease (LSD) epidemic in France. The size of the stock of vaccines needed was calculated based on a series of simple equations that use some trigonometric functions and take into account the spread of the disease, the time required to obtain good vaccination coverage and the cattle density in the affected region. Assuming a 7-weeks period to vaccinate all the animals and a spread of the disease of 7.3 km/week, the vaccination of 740 716 cattle would be enough to control an epidemic of LSD in France in 90% of the simulations (608 196 cattle would cover 75% of the simulations). The results of this simple method were then validated using a dynamic simulation model, which served as reference for the calculation of the vaccine stock required. The differences between both models in different scenarios, related with the time needed to vaccinate the animals, ranged from 7% to 10.5% more vaccines using the simple method to cover 90% of the simulations, and from 9.0% to 13.8% for 75% of the simulations. The model is easy to use and may be adapted for the control of different diseases in different countries, just by using some simple formulas and few input data., Competing Interests: The authors have declared that no competing interests exist.

The objective of the present study was to access the titres and duration of maternally derived neutralizing antibodies against lumpy skin disease virus (LSDV) in calves born to immunized dairy cows. The study was conducted in a Greek farm of 200 Holstein cows which were immunized with a homologous Neethling strain-based attenuated vaccine. Composite colostrum samples were obtained from 18 selected cows at the day of calving. Blood samples were obtained from each dam-calf pair prior to the first colostrum feeding and from the calves successively on the third day after calving and on monthly intervals thereafter, until day 150. Passive transfer of antibodies in calves was evaluated by determining the levels of total protein in serum samples collected on day 3. Neutralizing antibody (NAb) titres against LSDV in colostrum and serum samples were determined by virus neutralization test. Colostrum NAb titres >1:160 were associated with the presence of NAbs in serum from calves 3 days after birth. Out of the 18 calves, which received colostrum with NAbs, 16 (88.9%) had detectable NAbs in their serum. Thereafter, a declining percentage of calves with detectable serum NAbs was recorded (38.5% on day 90 and 0% on days 120 and 150). Only calves with high NAb titres on day 3 had detectable serum NAbs until day 90 after calving. Thus, a significant number of calves were not protected by maternal antibodies against the disease after the age of 3 months and likely even after the age of 2 months. The findings of the present study substantiate that current recommendation for vaccination can be amended, so as to minimize the susceptible bovine population and enable optimized LSD prevention and eradication., (© 2018 Blackwell Verlag GmbH.)

Lumpy skin disease (LSD) is an emerging infectious disease of cattle. Since 2012, it has been seen throughout the Middle East region. The aim of this study was to compare the humoral response of three different dosages of the RM65 sheep pox (SPP) vaccine to assess the use of ten times sheep dose of the RM65 vaccine against lumpy skin disease, and to explore the possible causes of, and characterize the side effects caused by the RM65 vaccine. A blinded randomized collected study comprised 57 clinically normal, Holstein Friesian cattle which were randomly assigned into three experimental groups of 17 cattle according to the vaccine dose used (one, five and ten times the dose used for sheep in the field, and a control group of six cattle that did not receive the vaccine. Experimental animals were monitored closely for the development of any abnormality or side effects. Serum samples were collected for 6 weeks and were tested using serum neutralization assay. Decrease in total milk production was observed a week after vaccination and by the fifth week of the experiment, it had returned to prevaccination levels. Clinical side effects were seen in five animals that belong only to the group that received ten times of the SPP vaccine dose. Observed side effects included fever, decreased feed intake and milk production, as well as skin lesions. Skin nodules appeared between 7 and 17 days postvaccination, and remained for 11-17 days. Systemic reactions were likely to be associated with higher dosage and all affected cattle recovered uneventfully. Animals that received the highest dose (ten times the sheep dose) showed the best humoral response. The actual efficacy of the different concentration of the SPP RM65 should be evaluated based on a challenge experiment in a controlled environment., (© 2018 Blackwell Verlag GmbH.)

Lumpy skin disease virus (LSDV) is responsible for causing severe economic losses to cattle farmers throughout Africa, the Middle East, and more recently, South-Eastern Europe and Russia. It belongs to the Capripoxvirus genus of the Poxviridae family, with closely related sheeppox and goatpox viruses. Like other poxviruses, the viral genome codes for a number of genes with putative immunomodulatory capabilities. Current vaccines for protecting cattle against lumpy skin disease (LSD) based on live-attenuated strains of field isolates passaged by cell culture, resulting in random mutations. Although generally effective, these vaccines can have drawbacks, including injection site reactions and/or limited immunogenicity. A pilot study was conducted using a more targeted approach where two putative immunomodulatory genes were deleted separately from the genome of a virulent LSDV field isolate. These were open reading frame (ORF) 005 and ORF008, coding for homologues of an interleukin 10-like and interferon-gamma receptor-like gene, respectively. The resulting knockout constructs were evaluated in cattle for safety, immunogenicity and protection. Severe post-vaccinal reactions and febrile responses were observed for both constructs. Two calves inoculated with the ORF008 knockout construct developed multiple lesions and were euthanised. Following challenge, none of the animals inoculated with the knockout constructs showed any external clinical signs of LSD, compared to the negative controls. Improved cellular and humoral immune responses were recorded in both of these groups compared to the positive control. The results indicate that at the high inoculation doses used, the degree of attenuation achieved was insufficient for further use in cattle due to the adverse reactions observed., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The present study was performed to investigate the clinical impact and certain virological and haematological parameters following immunization of cattle against lumpy skin disease (LSD). The study was conducted in a dairy cattle farm (215 animals), immunized with a Neethling strain-based live vaccine. Twenty-seven animals (14 lactating cows, four dry cows and nine calves) were randomly selected for repetitive blood and saliva samplings. An EvaGreen-based real-time PCR was designed to differentiate vaccine from field LSDVs. Vaccinated animals underwent examination for adverse reactions. Nodule samples were collected from two representative cases for histopathological testing and virus identification. Milk yield was calculated based on bulk-tank measurements of all lactating cows (79). Viral DNA was detected between days 6-15 post-vaccination (p.v.) at 63% of the sampled animals (17/27). Saliva and bulk-tank milk samples were LSDV-negative. Pronounced swelling was observed at injection sites of 12% of the immunized animals (26/215), starting at day 6 p.v., and was resolved after 2-4 days. Small-sized (<0.5 cm) cutaneous lumps were developed between days 8-18 p.v. at 9% of the vaccinated animals (19/215). These were observed in adult cows and not in calves/heifers. Resolution was observable 10 days post-development. The vaccine virus was also identified in nodules and injection-site aspirates. Haematological changes (e.g., lower leucocyte counts) were observed in cows and not in calves. Daily milk production was being reduced during the first 12 days p.v. LSD immunization of cows resulted in nodules and low viraemia levels. The fact that nodules and haematological changes were not observed in calves, along with the low viraemia, supports the reduced virulence of the Neethling vaccine strain. The characteristic nodules in vaccinated animals could allow clinical differentiation from those observed in LSD. The developed real-time PCR efficiently differentiates infected from vaccinated cattle, and should be further validated as a tool in LSD surveillance., (© 2017 Blackwell Verlag GmbH.)

The current study was carried out in central and North-western parts of Ethiopia to assess the efficacy of Kenyan sheep pox virus strain vaccine (KS1 O-180) against natural lumpy skin disease (LSD) infection under field conditions by estimating its effect on the transmission and severity of the disease. For this study, an LSD outbreak was defined as the occurrence of at least one LSD case in a specified geographical area. An observational study was conducted on a total of 2053 (1304 vaccinated and 749 unvaccinated) cattle in 339 infected herds located in 10 sub-kebeles and a questionnaire survey was administered to 224 herd owners. Over 60% of the herd owners reported that the vaccine has a low to very low effect in protecting animals against clinical LSD; almost all of them indicated that the vaccine did not induce any adverse reactions. In the unvaccinated group of animals 31.1% were diagnosed with LSD while this was 22.5% in the vaccinated group (P<0.001). Severity of the disease was significantly reduced in vaccinated compared to unvaccinated animals (OR=0.68, 95% CI: 0.49; 0.96). Unvaccinated infected animals were more likely (predicted fraction=0.89) to develop moderate and severe disease than vaccinated infected animals (predicted fraction=0.84). LSD vaccine efficacy for susceptibility was estimated to be 0.46 (i.e. a susceptibility effect of 0.54) while the infectiousness effect of the vaccine was 1.83. In other words, the vaccine reduces the susceptibility by a factor of two and increases infectiousness by approximately the same amount. LSD transmission occurred in both vaccinated and unvaccinated animals, the estimated reproduction ratio (R) was 1.21 in unvaccinated animals compared to 1.19 in vaccinated ones, and not significantly different. In conclusion, KS1 O-180 vaccination, as applied currently in Ethiopia, has poor efficacy in protecting cattle populations against LSD, neither by direct clinical protection nor by reducing transmission, and this signifies the urgent need to either improve the quality of the vaccine or to develop potent alternative vaccines that will confer good protection against LSD., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Capripoxviruses (CaPVs) have been shown to be ideal viral vectors for the development of recombinant multivalent vaccines to enable delivery of immunogenic genes from ruminant pathogens. So far, the viral thymidine kinase (TK) gene is the only gene used to generate recombinants. A putative non-essential gene encoding a G-protein-coupled chemokine receptor subfamily homologue (GPCR) was targeted as an additional insertion site. Peste des petits ruminants (PPR) was chosen as a disease model. A new recombinant CaPV expressing the viral attachment hemagglutinin (H) of the PPR virus (PPRV) in the GPCR insertion site (rKS1-HPPR-GPCR) was generated in the backbone North African isolate KS1 strain of lumpy skin disease virus (LSDV). Comparison with the recombinant CaPV expressing the H of PPRV in the TK gene (rKS1-HPPR-TK) shown to induce protection against both PPR and LSD in both sheep and goats was assessed. The suitability of the GPCR gene to be a putative additional insertion site in the CaPV genome is evaluated and discussed., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The objective of this study is to present epizootiological data from the lumpy skin disease (LSD) outbreaks in Greece during 2015-16, following the implementation of emergency vaccination and total stamping-out, along with laboratory data regarding the genetic differentiation between field isolates and live attenuated vaccine virus strains. Descriptive geographical chronology analysis was conducted to present the progressive shift of the outbreaks westwards, and at the same time, the absence of further outbreaks in previously affected regional units where high vaccination coverage was achieved. Isolation and molecular characterization of LSDV from the first recorded case in Greece (Evros/GR/15 isolate) was performed. The two live attenuated LSD vaccine viruses, currently used for emergency immunization in Greece, were sequenced and compared to the Evros/GR/15 isolate, in 3 genomic regions (GPCR gene, RPO30 gene, and partial LSDV126/LSDV127 genes). Sequence comparisons revealed prominent differences between the Evros/GR/15 isolate and the vaccine strains. Phylogenetic analysis resulted in the classification of the Evros/GR/15 isolate in the same clade with all field LSDV isolates, whereas vaccine strains were grouped in a distinct cluster within the LSDV clade. Additional samples from animals presenting skin nodules (N=13) were characterized by sequencing in the 3 aforementioned genomic regions. Among them, in 5 animals that were vaccinated, the attenuated vaccine virus was identified. A PCR-RFLP method targeting the LSDV127 gene was developed and proved to be able to discriminate between the characterized field and vaccine strains. The findings of the present study substantiate the importance of timely and intensive vaccinations for the control of LSDV epizootic and the genetic differences between the Evros/GR/15 isolate and the vaccine strains. This provides the basis for the development of PCR-based DIVA assays, which would be of major importance for effective disease surveillance and stamping-out during LSD vaccination campaigns., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Sheep and goat pox continue to be important livestock diseases that pose a major threat to the livestock industry in many regions in Africa and Asia. Currently, several live attenuated vaccines are available and used in endemic countries to control these diseases. One of these is a partially attenuated strain of lumpy skin disease virus (LSDV), KS-1, which provides cross-protection against both sheep pox and goat pox. However, when used in highly stressed dairy cattle to protect against lumpy skin disease (LSD) the vaccine can cause clinical disease. In order to develop safer vaccines effective against all three diseases, a pathogenic strain of LSDV (Warmbaths [WB], South Africa) was attenuated by removing a putative virulence factor gene (IL-10-like) using gene knockout (KO) technology. This construct (LSDV WB005KO) was then evaluated as a vaccine for sheep and goats against virulent capripoxvirus challenge. Sheep and goats were vaccinated with the construct and the animals were observed for 21days. The vaccine appeared to be safe, and did not cause disease, although it induced minor inflammation at the injection site similar to that caused by other attenuated sheep and goat pox vaccines. In addition, no virus replication was detected in blood, oral or nasal swabs using real-time PCR following vaccination and low levels of neutralising antibodies were detected in both sheep and goats. Leukocytes isolated from vaccinated animals following vaccination elicited capripoxvirus-specific IFN-γ secretion, suggesting that immunity was also T-cell mediated. Following challenge with virulent capripoxvirus, vaccinated sheep and goats were found to be completely protected and exhibited no clinical disease. Furthermore, real-time PCR of blood samples at various time points suggested that viremia was absent in both groups of vaccinated animals, as opposed to capripoxvirus-related clinical disease and viremia observed in the unvaccinated animals. These findings suggest that this novel knockout strain of LSDV has potential as a vaccine to protect livestock against sheep pox and goat pox., (Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.)

This study intends to report the first emergence of lumpy skin disease (LSD) in Iraq, in addition to describing its related clinical signs. In August 2013, 21 cases of four outbreaks developed clinical signs suggestive of LSD in the Nineveh (Mosul) and Baghdad Governorates, which were considered as the first infected foci of LSD in Iraq. The disease was diagnosed tentatively, on the basis of clinical signs and epidemiological features, and it was confirmed as positive by the polymerase chain reaction and histopathological features. In September 2013, eight new outbreaks of LSD also appeared in Baghdad and Nineveh. In 2014, the disease spread rapidly to the governorates of Kirkuk, Salah Al-Din, Al-Anbar, Diyala, Wasit, Babil, Karbala, Najaf, Al-Diwaniyah, Muthanna, Maysan, DhiQar and Basra. The total number of infected cows and calves reported was 7396 and 227, respectively. The apparent morbidity and mortality rates were 9.11% and 0.51%, respectively, while the apparent case-fatality rate was 5.56%. Skin nodules, anorexia, reduce in milk production and decrease in bodyweight were the common clinical signs. Moreover, myiasis and mastitis were seen as complications in some infected animals. Attempts were made to stop the distribution of the disease including quarantine and treatment, control over animal movement and arthropod control. Ring vaccination was used in a 10 km radius zone around the outbreak with live sheep pox vaccine. The highly contagious transboundary nature of the LSD, its endemic distribution in the Iraqi neighbouring countries, and the current armed conflict in the area were the possible factors for the disease being introduced into the country. LSD had spread through the Middle East and Gulf peninsula and could be a cause of danger to the rest of Asia and Europe. International precaution, cooperation and exchange of information could guarantee the prevention and further spread of the disease to the rest of Asia and Europe., (© 2015 Blackwell Verlag GmbH.)

Lumpy skin disease (LSD) is a viral disease of cattle and buffalo, caused by a Capripox virus. A field study was performed during an LSD epidemic which occurred in 2012-2013 in Israel, in order to assess the efficacy of two commercial vaccines for protection against LSD. Fifteen dairy herds, vaccinated 2-5 months prior to study onset with a single dose of 10(2.5) TCID50 of RM65 attenuated sheep-pox vaccine, and not affected previously, were enrolled in the study. 4694 cows were randomized to be either vaccinated with a 10(3.5) TCID50/dose of RM65 vaccine (x10RM65) or with a same dose of an attenuated Neethling LSD virus vaccine. A case of LSD was defined as the appearance of at least 5 lesions typical to LSD and a severe case was defined if this sign was accompanied by either fever (>39.5°C) or/and a 20% reduction in milk production. Deep lesion biopsies and blood samples were collected from 64.5% of the cases in an attempt to detect DNA of LSD virus by PCR and to differentiate between the wild strain and the vaccine Neethling strain. Seventy-six cows were affected by LSD in 8 herds with an incidence of 0.3-5.7%. Mantel-Haenszel relative risk (RRMH) for LSD morbidity at least 15 days after vaccination in x10RM65 vs. Neethling was 2.635 (CI95%=1.44-4.82) and 11.2 (2.3-54.7) for severe morbidity. RRMH for laboratory confirmed cases was 4.28 (1.59-11.53). An incidence of 0.38% (9/2356) of Neethling associated disease was observed among Neethling vaccinated cows while no such disease occurred in x10RM65 vaccinated cows. We conclude that the Neethling vaccine is significantly more effective than x10RM65 in preventing LSD morbidity, though it might cause a low incidence of Neethling associated disease. No transmission of the Neethling strain to non-Neethling vaccinated cows was observed in this study., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The safety, immunogenicity and efficacy of three commercially available vaccines against lumpy skin disease (LSD) in cattle have been evaluated using a combination of vaccine challenge experiments and the monitoring of immune responses in vaccinated animals in the field. The three vaccines evaluated in the study included two locally produced (Ethiopian) vaccines (lumpy skin disease virus (LSDV) Neethling and Kenyan sheep and goat pox (KSGP) O-180 strain vaccines) and a Gorgan goat pox (GTP) vaccine manufactured by Jordan Bio-Industries Centre (JOVAC). The latter vaccine was evaluated for the first time in cattle against LSDV. The Ethiopian Neethling and KSGPO-180 vaccines failed to provide protection in cattle against LSDV, whereas the Gorgan GTP vaccine protected all the vaccinated calves from clinical signs of LSD. There was no significant difference in protective efficacy detected between two dosage levels (P=0.2, P=0.25, and P=0.1 for KSGP, Neethling and Gorgan vaccines, respectively). Additionally, the Gorgan GTP vaccinated cattle showed stronger levels of cellular immune responses measured using Delayed-Type Hypersensitivity (DTH) reactions at the vaccination site indicating higher levels of immunogenicity produced by the GTPV vaccine in cattle, as opposed to the other two vaccines. This study indicated, for the first time, that the Gorgan GTP vaccine can effectively protect cattle against LSDV and that the Neethling and KSGP O-180 vaccine were not protective. The results emphasise the need for molecular characterization of the Neethling and KSGP O-180 vaccine seed viruses used for vaccine production in Ethiopia. In addition, the potency and efficacy testing process of the Ethiopian LSD Neethling and KSGP O-180 vaccines should be re-evaluated., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Lumpy skin disease is of significant economic impact for the cattle industry in Africa. The disease is currently spreading aggressively in the Near East, posing a threat of incursion to Europe and Asia. Due to cross-protection within the Capripoxvirus genus, sheep pox virus (SPPV) vaccines have been widely used for cattle against lumpy skin disease virus (LSDV). In the Middle East and the Horn of Africa these vaccines have been associated with incomplete protection and adverse reactions in cattle post-vaccination. The present study confirms that the real identity of the commonly used Kenyan sheep and goat pox vaccine virus (KSGP) O-240 is not SPPV but is actually LSDV. The low level attenuation of this virus is likely to be not sufficient for safe use in cattle, causing clinical disease in vaccinated animals. In addition, Isiolo and Kedong goat pox strains, capable of infecting sheep, goats and cattle are identified for potential use as broad-spectrum vaccine candidates against all capripox diseases., (Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.)

This study was conducted in and around Debre Zeit town to assess the field efficacy of LSD vaccine in use and overview associated disease impact. The study comprised cross-sectional and retrospective study design which employed active disease follow-up, semi-structured questionnaire survey and molecular techniques. The finding revealed that the Kenyan sheep pox vaccine strain used for the control of LSD did not confer expected protection. From the total of 476 animals observed, 22.9% and 2.31% cattle were found sick and dead due to LSD, respectively. Breed specific morbidity rate was 22.5% in Holstein Friesian-zebu cross and 25.9% in local zebu breed. The disease was observed to be more serious in young animals and also in females. A trend of seasonality was also observed in its occurrence. The study finding urges the need for investigation of vaccine failure including vaccine matching and alternative vaccine development., (Copyright © 2013. Published by Elsevier B.V.)

A cross-sectional study was conducted to estimate the seroprevalence of lumpy skin disease (LSD) in the different agro-climatic zones prevailing in Ethiopia. A total of 2368 serum samples were collected from 42 kebeles located in 15 districts and tested using indirect fluorescent antibody test (IFAT) and virus neutralization test (VNT). The herd and animal true LSD serological prevalence were estimated in each agro-climate zone using a Bayesian model. The intra-cluster correlation coefficient (ICC) was evaluated using a random-effect model. According to the serological prevalence estimations, LSD affected differently the three agro-climatic zones considered. Herd level seroprevalence was higher in the midland agro-climate zone 64% (95% CI: 53-74) as compared to the highland 26% (95% CI: 17-36) and the lowland 50% (95% CI: 40-60) agro-climates. Animal level seroprevalence in infected herds was also higher in the midland agro-climate zone 31% (95% CI: 24-40) than in the highland and lowland zones (24% (95% CI: 18-31) and 23% (95% CI: 18-29), respectively). Higher ICC value in the highland agro-climate zone implies that increased sample sizes should be particularly required for this zone in future studies to estimate LSD prevalence or incidence with a desired precision level. This seroprevalence study also suggests that the prevalence of LSD infection in Ethiopia is higher than what has been previously reported. In the light of these updated estimations, we discuss options to trigger appropriate control measures in the future., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Lumpy skin disease (LSD) is an economically devastating emerging viral disease of cattle. Lumpy skin disease is currently endemic in most African countries and has recently spread out of Africa into the Middle East region. In this article, we review the putative mechanisms of spread of LSD into the Middle East and the risks of further spread into Turkey, Europe and Asia. We also review the latest findings on the epidemiology of LSD, its mechanisms of transmission, the potential role of wildlife in its maintenance and spread and the diagnostic tests and control methods currently available., (© 2011 Blackwell Verlag GmbH.)

The financial cost of clinical Lumpy Skin Disease (LSD) and the financial benefit of its control through vaccination were studied based on questionnaire survey in Oromia region of Ethiopia from the perspective of livestock farmers. Production loss impacts for local zebu cattle were compared with those of Holstein Friesian (HF)/crossbred cattle in the study area. Annual cumulative incidence of LSD infection in HF/crossbred and local zebu cattle were 33.93% (95% CI: 30.92-36.94) and 13.41% (95% CI: 12.6-14.25) respectively and significantly different (p<0.05). Annual mortality was also significantly higher in HF/crossbred 7.43% (95% CI: 5.76-9.10) than in local zebu cattle 1.25% (95% CI: 0.98-1.52). The annual financial cost was calculated as the sum of the average production losses due to morbidity and mortality arising from milk loss, beef loss, traction power loss, and treatment and vaccination costs at the herd level. The financial cost in infected herds was estimated to be USD 6.43 (5.12-8) per head for local zebu and USD 58 (42-73) per head for HF/crossbred cattle. A partial budget analysis was used to estimate the financial benefit of an annual vaccination program in both the local zebu and HF/crossbred cattle farming systems. The marginal rate of return (MRR) gained from this control intervention was estimated to be 34 (3400%) and the net benefit per head was USD 1 for local zebu and USD 19 for HF/crossbred cattle. Vaccination thus enabled financial costs due to LSD to be reduced by 17% per head in local zebu herds and 31% per head in HF/crossbred herds. These results could provide guidance to producers and the government in their endeavors to control the disease., (Copyright © 2011 Elsevier B.V. All rights reserved.)

An outbreak of lumpy skin disease (LSD) was reported in 2006 in Egypt affecting 16 provinces. Biopsies and post-mortem tissue samples were collected from calves that showed typical clinical signs of LSD and fixed in formalin. These samples were collected from a private dairy farm in the Damietta province of Egypt. Formalin-fixed paraffin-embedded tissue samples were assessed using histology, and skin lesions were classified as either acute or subacute/chronic. Both lumpy skin disease virus (LSDV) DNA detected by polymerase chain reaction and LSDV antigen detected by immunohistochemistry using a capripoxvirus-specific monoclonal antibody were observed in the acute skin lesions and in some subacute/chronic skin lesions., (© 2011 Blackwell Verlag GmbH.)

In Egypt, protection of cattle against lumpy skin disease (LSD) was carried out using a sheep poxvirus (Kenyan strain) vaccination strategy. In the present study 15 skin nodules from LSD suspected cows and 5 scab samples from sheep pox (SP) suspected sheep were collected. Hyperimmune rabbit sera to Lumpy skin disease virus (LSDV)/Ismailyia88 strain and sheep pox virus (SPV)/ Kenyan vaccinal strain were prepared. The causative agent in the collected samples was identified using immunoflourescence (IF) and immunoperoxidase techniques. Of the 15 skin nodules suspected of LSD, 10 showed a positive reaction and 3 out of 5 skin scabs suspected of sheeppox were found to be positive. An antigenic correlation between field skin isolate of LSDV, tissue culture adapted LSDV/Ismailyia88 strain, field skin isolate of SPV and SPV/Kenyan vaccinal strain was studied using prepared hyperimmune sera. Also, nucleotide sequence of the PCR amplified attachment gene fragments of field skin isolate of LSDV, tissue culture adapted LSDV/Ismailyia88 strain, field skin isolate of SPV and SPV /Kenyan vaccinal strain were compared. The results revealed that the four used viruses were antigenically identical. Sequence analysis indicated that field skin LSDV isolate is more related to tissue culture adapted LSDV/Ismailyia88 strain than to vaccinal SPV/ Kenyan strain and the skin isolate of SPV is more closely related to field skin isolate of LSDV than to SPV/Kenyan vaccinal strain. Thus, further study should be applied on the advantage of a LSD vaccine prepared from LSDV in protection of cattle against LSD compared to the commonly used sheep pox vaccine.

The ultimate goal of a vaccine is to protect vaccinated animals against re-exposure to the same pathogen and provide sterile immunity. However, a cutaneous clinical manifestation appeared, following re-exposure of cattle that had been vaccinated with the RM65 strain, to LSDV infection during an epidemic in 2006-2007. Four thousand six hundred and seven vaccinated cows entered the study after being re-exposed to LSDV infection. Of them, 513 (11%) presented lumps, and there was a marked difference between the proportions of dairy and feedlot animals that were affected: 146 out of 3517 and 367 out of 1090 (6.6 and 33.7%, respectively). This data suggests that the potency of the vaccine need to be re-assessed for beef cattle.

Lumpy skin disease along with sheep pox and goatpox are the most serious poxvirus diseases of livestock, and are caused by viruses that belong to the genus Capripoxvirus within the subfamily Chordopoxvirinae, family Poxviridae. To facilitate the study of lumpy skin disease pathogenesis, we inoculated eight 4- to 6-month-old Holstein calves intravenously with lumpy skin disease virus (LSDV) and collected samples over a period of 42 days for analysis by virus isolation, real-time PCR and light microscopy. Following inoculation, cattle developed fever and skin nodules, with the extent of infection varying between animals. Skin nodules remained visible until the end of the experiment on day post-inoculation (DPI) 42. Viremia measured by real-time PCR and virus isolation was not observed in all animals but was detectable between 6 and 15 DPI. Low levels of viral shedding were observed in oral and nasal secretions between 12 and 18 DPI. Several tissues were assessed for the presence of virus at DPI 3, 6, 9, 12, 15, 18 and 42 by virus isolation and real-time PCR. Virus was consistently detected by real-time PCR and virus isolation at high levels in skin nodules indicating LSDV has a tropism for skin. In contrast, relatively few lesions were observed systemically. Viral DNA was detected by real-time PCR in skin lesions collected on DPI 42. Cattle developing anti-capripoxvirus antibodies starting at DPI 21 was detected by serum neutralization. The disease in this study varied from mild with few secondary skin nodules to generalized infection of varying severity, and was characterized by morbidity with no mortality.

The performance of indirect fluorescence antibody test (IFAT) for serological diagnosis and screening of lumpy skin disease (LSD) was evaluated using methods without gold standard. Virus neutralization test (VNT) was used as the second test and the study sites were selected from two different geographical places in Ethiopia to get different disease prevalence. The analysis of conditional dependent Bayesian model for the accuracy of IFAT showed that sensitivity, specificity, prevalence of the population Pi(1) and the population Pi(2) were 0.92 (0.89-0.95), 0.88 (0.85-0.91), 0.28 (0.25-0.32) and 0.06 (0.048-0.075), respectively. The posterior inferences obtained for VNT sensitivity, specificity and conditional correlation between the tests for sensitivity (rhoD) and specificity (rhoDc) were 0.78 (0.74-0.83), 0.97 (0.95-0.99), 0.052 (-0.03-0.15) and 0.019 (-0.01-0.06), respectively. The interval estimation of conditional correlation for both sensitivity and specificity clusters around zero and thus conditional dependence between the two tests was not significant. Although accuracy measure would not be the only basis for test selection, the result of our study demonstrated that IFAT has a reasonable high accuracy to be used for the diagnosis and sero-surveillance analysis of LSD in the target population.

Twelve serologically negative bulls were used, six were vaccinated with a modified live LSD vaccine and six unvaccinated. All were then experimentally infected with a virulent field strain of LSDV. No clinical abnormality was detected following vaccination, and mild clinical signs were seen in four vaccinated bulls following challenge. Virus was not found in semen of vaccinated bulls. Two of the unvaccinated bulls developed severe LSD and four showed mild symptoms, all excreted the virus in the semen following challenge. This study confirmed the ability of LSD vaccination to prevent the excretion of LSDV in semen of vaccinated bulls.

The South African vaccine strain of lumpy skin disease virus (type SA-Neethling) is currently being developed as a vector for recombinant vaccines of economically important livestock diseases throughout Africa. In this study, the feasibility of using the viral thymidine kinase gene as the site of insertion was investigated and recombinant viruses were evaluated in animal trials. Two separate recombinants were generated and selected for homogeneity expressing either the structural glycoprotein gene of bovine ephemeral fever virus (BEFV) or the two structural glycoprotein genes of Rift Valley fever virus (RVFV). Both recombinants incorporate the enhanced green fluorescent protein (EGFP) as a visual marker and the Escherichia coli guanine phosphoribosyl transferase (gpt) gene for dominant positive selection. The LSDV-RVFV recombinant construct (rLSDV-RVFV) protected mice against virulent RVFV challenge. In a small-scale BEFV-challenge cattle trial the rLSDV-BEFV construct failed to fully protect the cattle against virulent challenge, although both a humoral and cellular BEFV-specific immune response was elicited.

The genomic sequences of 3 strains of Lumpy skin disease virus (LSDV) (Neethling type) were compared to determine molecular differences, viz. the South African vaccine strain (LW), a virulent field-strain from a recent outbreak in South Africa (LD), and the virulent Kenyan 2490 strain (LK). A comparison between the virulent field isolates indicates that in 29 of the 156 putative genes, only 38 encoded amino acid differences were found, mostly in the variable terminal regions. When the attenuated vaccine strain (LW) was compared with field isolate LD, a total of 438 amino acid substitutions were observed. These were also mainly in the terminal regions, but with notably more frameshifts leading to truncated ORFs as well as deletions and insertions. These modified ORFs encode proteins involved in the regulation of host immune responses, gene expression, DNA repair, host-range specificity and proteins with unassigned functions. We suggest that these differences could lead to restricted immuno-evasive mechanisms and virulence factors present in attenuated LSDV strains. Further studies to determine the functions of the relevant encoded gene products will hopefully confirm this assumption. The molecular design of an improved LSDV vaccine is likely to be based on the strategic manipulation of such genes.

Sheep pox, goat pox and lumpy skin disease (Neethling) are diseases of sheep, goats and cattle respectively, caused by strains of poxvirus, within the genus Capripoxvirus. Strains affecting sheep and goats are not totally host-specific; some cause disease in both sheep and goats while others may cause disease in only one species. Those causing disease in cattle appear to be specific for cattle, and this is reflected in the different geographical distribution of lumpy skin disease (LSD) and sheep pox and goat pox (sheep and goat pox); LSD is confined to Africa, while sheep and goat pox are present in Africa north of the equator, and throughout West Asia and India, as far East as China and Bangladesh. Occasionally sheep and goat pox spreads from Turkey into Greece. All strains of capripoxvirus so far examined are antigenically indistinguishable, and recovery from infection with one strain provides immunity against all other strains. Because of this antigenic homology among all strains, there is the potential to use a single vaccine strain to protect cattle, sheep and goats.

Rabies virus (RV) readily infects cattle and causes a fatal neurological disease. A stable vaccine, which does not require the maintenance of a cold chain and that is administered once to elicit lifelong immunity to rabies would be advantageous. The present study describes the construction of a live recombinant lumpy skin disease virus (LSDV) vaccine, expressing the glycoprotein of rabies virus (RG) and assessment of its ability to generate a humoral and cellular immune response against rabies virus in cattle. Cattle inoculated with the recombinant virus (rLSDV-RG) developed humoral immunity that was demonstrated in ELISA and neutralisation assays to RV. High titres of up to 1513IU/ml of RV neutralising antibodies were induced. In addition, peripheral blood mononuclear cells from rLSDV-RG-immunised animals demonstrated the ability to proliferate in response to stimulation with inactivated RV, whereas the animal vaccinated with wild type LSDV did not. This recombinant vaccine candidate thus has the potential to be used in ruminants as a cost-effective vaccine against both lumpy skin disease (LSD) and rabies.

This article reviews some of the important aspects of lumpy skin disease (LSD) that may impact on its successful control. A resurgence of the disease in the last decade has highlighted some constraints of the Neethling strain vaccine, but there is no evidence of vaccine breakdowns owing to the presence of heterologous field strains. More research is needed on epidemiology and transmission of LSD in South Africa to formulate control measures.

Cattle were vaccinated with differing doses of an equal mixture of capripox-rinderpest recombinant viruses expressing either the fusion protein (F) or the haemagglutinin protein (H) of rinderpest virus. Animals vaccinated with 2 x 10(4) p.f.u. or greater of the combined viruses were completely protected against challenge, 1 month later, with both virulent rinderpest and lumpy skin disease viruses. Vaccination with any of the doses did not induce any adverse clinical response in the animals or transmission of the vaccine virus between animals. All cattle challenged 6 or 12 months after vaccination with 2 x 10(5) p.f.u. of the mixture of recombinant viruses were protected from severe rinderpest disease. Ten out of 18 were completely protected while the remaining 8 developed mild clinical signs of rinderpest. Cattle vaccinated with the recombinant vaccines after prior infection with the parental capripox virus showed more marked clinical signs of rinderpest after challenge with virulent rinderpest, but 9 out of 10 recovered, compared with 80% mortality in the unvaccinated controls.

Lumpy skin disease caused by a capripoxvirus was observed in a captive-bred female Arabian oryx (Oryx leucoryx) at the National Wildlife Research Center, Taif, Saudi Arabia. Clinical signs included severe general depression with fever, anorexia, greater than 1,000 nodular cutaneous lesions and gradual recovery over 2 mo. The virus was found by electron microscopy and paired sera showed an increasing virus neutralization antibody titer against capripoxvirus. A serologic survey of the herd of 90 oryx showed a low prevalence (2%) of this infection. This report describes the first case of lumpy skin disease in an Arabian oryx.