Ronchi Gaetano Federico, Iorio Mariangela, Serroni Anna, Caporale Marco, Testa Lilia, Palucci Cristiano, Antonucci Daniela, Capista Sara, Traini Sara, Pinoni Chiara, Di Matteo Ivano, Laguardia Caterina, Armillotta Gisella, Profeta Francesca, Valleriani Fabrizia, Di Felice Elisabetta, Di Teodoro Giovanni, Sacchini Flavio, Luciani Mirella, Di Pancrazio Chiara, Podaliri Vulpiani Michele, Rossi Emanuela, Salini Romolo, Morelli Daniela, Ferri Nicola, Mercante Maria Teresa, Di Ventura Mauro
Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise "G. Caporale", 64100 Teramo, Italy.
Department of Veterinary Medicine, University of Teramo, 64100 Teramo, Italy.
Vaccines (Basel). 2024 Nov 21;12(12):1302. doi: 10.3390/vaccines12121302.
Lumpy skin disease virus ( family- genus) is the aetiological agent of LSD, a disease primarily transmitted by hematophagous biting, affecting principally cattle. Currently, only live attenuated vaccines are commercially available, but their use is limited to endemic areas. There is a need for safer vaccines, especially in LSD-free countries. This research aims to develop and test a safe and efficacious inactivated vaccine. Moreover, in this study, we used keyhole limpet hemocyanin (KLH) as a positive marker to distinguish infected from vaccinated animals (DIVA). Lumpy skin disease virus was propagated on primary lamb testis cells and Madin-Darby bovine kidney cells (PLT and MDBK, respectively), and four inactivated vaccines were produced. The vaccines differed from each other with the addition or not of KLH and in cells used for virus propagation. To evaluate the safety and immunogenicity, the vaccines and two placebos were administered to six groups comprising six male calves each, and antibody response was investigated using both an enzyme-linked immunosorbent assay (ELISA) and a serum neutralization (SN) test. In addition, the LSD/γ-interferon test and KLH (IgM-IgG) ELISA were performed on the collected samples. Furthermore, the use of KLH allowed us to distinguish vaccinated animals in the ELISA results, without any interference on the strength of the immune response against the LSDV. Finally, the efficacy of one of four vaccines was investigated through a challenge, in which one group of vaccinated animals and one animal control group were infected with a live field strain of LSDV. Four out of the six control animals showed severe clinical signs suggestive of LSD, and, therefore, were euthanized for overcoming the predetermined limit of clinical score. By contrast, the vaccinated animals showed only mild symptoms, suggesting a reduction in severe disease notwithstanding the incapability of the vaccine in reducing the virus shedding. The vaccines produced were safe and able to elicit both a humoral and a cellular immune response, characteristics that, together with the demonstrated efficacy, make our vaccine a good candidate for countering the LSD spread in disease-free countries, thus also facilitating disease containment throughout the application of a DIVA strategy.
结节性皮肤病病毒（科-属）是结节性皮肤病的病原体，该疾病主要通过吸血叮咬传播，主要影响牛。目前，只有减毒活疫苗可在市场上买到，但其使用仅限于流行地区。需要更安全的疫苗，特别是在无结节性皮肤病的国家。本研究旨在开发和测试一种安全有效的灭活疫苗。此外，在本研究中，我们使用匙孔血蓝蛋白（KLH）作为阳性标记物，以区分感染动物和接种疫苗的动物（DIVA）。结节性皮肤病病毒在原代羔羊睾丸细胞和马-达二氏牛肾细胞（分别为PLT和MDBK）上增殖，并生产了四种灭活疫苗。这些疫苗因添加或未添加KLH以及用于病毒增殖的细胞不同而有所差异。为了评估安全性和免疫原性，将疫苗和两种安慰剂分别接种到六个组中，每组六头雄性犊牛，并使用酶联免疫吸附测定（ELISA）和血清中和（SN）试验研究抗体反应。此外，对采集的样本进行了结节性皮肤病/γ-干扰素试验和KLH（IgM-IgG）ELISA。此外，使用KLH使我们能够在ELISA结果中区分接种疫苗的动物，而不会对针对结节性皮肤病病毒的免疫反应强度产生任何干扰。最后，通过攻毒试验研究了四种疫苗之一的效力，其中一组接种疫苗的动物和一个动物对照组感染了结节性皮肤病病毒的现场活毒株。六只对照动物中有四只出现了提示结节性皮肤病的严重临床症状，因此，为了克服预定的临床评分限值而实施安乐死。相比之下，接种疫苗的动物仅表现出轻微症状，这表明尽管疫苗无法减少病毒 shedding，但严重疾病有所减少。所生产的疫苗是安全的，能够引发体液免疫和细胞免疫反应，这些特性与已证明的效力一起，使我们的疫苗成为在无病国家对抗结节性皮肤病传播的良好候选疫苗，从而也有助于通过应用DIVA策略控制疾病。
