doi: 10.15389/agrobiology.2024.4.787eng
UDC: 619:616.98:578.842.1:615.371
IMMUNOBIOLOGICAL EVALUATION OF THE CANDIDATE VACCINE STRAIN MK-200 OF THE AFRICAN SWINE FEVER VIRUS
M.E. Vlasov, D.A. Kudrjashov, O.L. Kolbasova, V.M. Lyska,
S.Yu. Morgunov, E.Yu. Pivova, M.S. Diumin, I.P. Sindryakova,
A.D. Sereda ✉
Federal Research Center for Virology and Microbiology, 1, ul. Akademika Bakuleva, pos. Vol’ginskii, Petushinskii Region, Vladimir Province, 601125 Russia, e-mail sereda-56@mail.ru (✉ corresponding author),vlasovmikhail1993@yandex.ru, dima_kudryashov@mail.ru, olgakolbasova@gmail.com, vliska@yandex.ru, dohliy55555@mail.ru, lenamail09@inbox.ru, dms-magus@mail.ru, yasnen-ko@mail.ru
ORCID:
Vlasov M.E. orcid.org/0000-0002-8324-3256
Pivova E.Yu. orcid.org/0000-0003-4831-0852
Kudrjashov D.A. orcid.org/0000-0002-6793-0195
Diumin M.S. orcid.org/0000-0003-2736-515X
Kolbasova O.L. orcid.org/0000-0001-5153-0982
Sindryakova I.P. orcid.org/0000-0002-5947-9402
Lyska V.M. orcid.org/0000-0001-5302-3108
Sereda A.D. orcid.org/0000-0001-8300-5234
Morgunov S.Yu. orcid.org/0000-0001-9730-3179
Final revision received October 12, 2023
Accepted January 09, 2024
African swine fever (ASF, causative agent African swine fever virus, ASFV) is a fatal hemorrhagic viral infection of domestic pigs and Eurasian wild boars (Sus scrofa). Depending on the properties of isolates/strains, the course of the disease can be peracute, acute, subacute, chronic, or asymptomatic. The global epizootic of ASF has stimulated the development and study of candidate vaccine strains, primarily recombinant or attenuated, considered as the basis for first-generation vaccines. In this study, two cycles of viral DNA replication were identified in pigs, inoculated with the ASFV candidate vaccine strain MK-200. The first cycle occurred on days 17-21, and the second on days 56-70 post-inoculation. The aim of the study was the evaluation of the immunobiological characteristics of the candidate ASFV vaccine strain MK-200 based on observations of the clinical condition, the presence of virus-specific DNA, and virus-specific antibodies in samples obtained from the pigs. The study was conducted in 2022 at the Federal Research Center for Virology and Microbiology (FRCVM). Clinically healthy large white breed pigs (Sus domesticus) aged 2-3 months were used. ASFV virulent strains Mozambique-78 (III seroimmunotype, V genotype) and Stavropol 01/08 (VIII seroimmunotype, II genotype) and the attenuated strain MK-200 obtained by selection from the Mozambique-78 strain, with infectious titers of 107.0-108.0 HAU50/ml were obtained from the state collection of microorganisms of FRCVM. The primary culture of pig leukocyte cells (LC) was prepared according to GOST 28573-90. ASFV infectious titers were determined in LC cultures by hemadsorption assay and calculated by the method of B.A. Kerber and I.P. Ashmarin. The experimental design included intramuscular inoculation of 10 pigs with ASFV (strain MK-200) at a dose of 106.0 HAU50 on day 0. Samples for study were collected on days 0, 3, 5, 7, 14, 17, 21, 28, 35, 42, 49, 56, 63, 70, and 77 post-infection (p.i.). The body temperature of the experimental animals was measured rectally throughout the all observation period. Blood samples were collected by puncturing the jugular vein. To obtain saliva samples, pigs were given strands of rope to chew (LLC TD PROMT, Russia) for 30 min. The wet rope strands were squeezed into clean polyethylene bags (LLC TD PROMT, Russia), and the collected saliva was transferred to centrifuge tubes (Thermo Fisher Scientific, USA). Cheek swabs were collected using sterile polyester swabs with plastic applicators (MiniMed, Russia). The MagMAX™ Pathogen RNA/DNA Kit (Thermo Fisher Scientific, USA) was used to extract nucleic acids. Real-time PCR (qPCR) was performed using the IDEXX RealPCR ASFV DNA Mix test system (IDEXX, USA). To detect antibodies to ASFV proteins in pig serum, the ID Screen® African Swine Fever Competition test system (IDVet, France) was used. We revealed a linear relationship between Ct values and infectious titers in 10-fold dilutions of virus-containing suspensions obtained by infecting LC cultures with ASFV strains Mozambique-78 or Stavropol 01/08. This allowed the conversion of data obtained from further blood and oral cavity sample studies in qPCR into infectious titer values. Of the 10 animals inoculated with the MK-200 strain, only three showed a brief (1-2 days) increase in body temperature above the physiological norm (40.1-40.6 °С) between days 5 and 7 p.i. The body temperature of all remained animals was within physiological norms during the first 10 days. From days 8 to 77 p.i., in all animals no clinical signs of ASF were observed. Viral DNA was detected in the samples from days 3-5 p.i. The minimum Ct values (maximum amount of target matrix) in qPCR were observed from days 17-21 p.i., with the proportion of positive samples reaching 60-100 %. Calculated viremia values based on the linear relationship between ASFV infectious titers and Ct values did not exceed 104.0 HAU50/ml from days 0 to 63 p.i. and were below 101.9 HAU50/ml from day 70 p.i. Throughout the experiment, cyclic viremia and the potential for virus shedding through the oral cavity were observed. This indicates the risks of horizontal and vertical transmission of the vaccine strain to susceptible animals through direct or indirect contact. We recommend to the developers of candidate live vaccines against ASF to provide data on viremia and virus shedding studies for a period of 2.5 to 4 months post-vaccination.
Keywords: African swine fever, candidate vaccines, immunobiological evaluation, Real-time PCR.
REFERENCES
- Blome S., Franzke K., Beer M. African swine fever — a review of current knowledge. Virus Research, 2020, 287: 198099 CrossRef
- Boinas F.S., Hutchings G.H., Dixon L.K., Wilkinson P.J. Characterization of pathogenic and non-pathogenic African swine fever virus isolates from Ornithodoros erraticus inhabiting pig premises in Portugal. Journal of General Virology, 2004, 85(8): 2177-2187 CrossRef
- Dixon L.K., Alonso C., Escribano J.M., Martins C., Revilla Y., Salas M.L., Takamatsu H. Asfarviridae. Virus taxonomy. Classification and nomenclature of viruses. Ninth report of the international committee on taxonomy of viruses (ICTV). Elsevier, Oxford, 2011: 153-162.
- Alonso C., Borca M., Dixon L., Revilla Y., Rodriguez F., Escribano J.M., ICTV Report Consortium. CTV virus taxonomy profile: Asfarviridae. Journal of General Virology, 2018, 99(5): 613-614 CrossRef
- Brake D.A. African swine fever modified live vaccine candidates: transitioning from discovery to product development through harmonized standards and guidelines. Viruses, 2022, 14(12): 2619 CrossRef
- Sereda A.D., Balyshev V.M., Kazakova A.S., Imatdinov A.R., Kolbasov D.V. Protective properties of attenuated strains of African swine fever virus belonging to seroimmunotypes I-VIII. Pathogens, 2020, 9(4): 274 CrossRef
- Sereda A.D., Balyshev V.M. Voprosy virusologii, 2011, 56(4): 38-42 (in Russ.).
- Bosch-Camós L., Alonso U., Esteve-Codina A., Chang C.Y., Martín-Mur B., Accensi F., Muñoz M., Navas M.J., Dabad M., Vidal E., Pina-Pedrero S., Pleguezuelos P., Caratù G., Salas M.L., Liu L., Bataklieva S., Gavrilov B., Rodríguez F., Argilaguet J. Cross-protection against African swine fever virus upon intranasal vaccination is associated with an adaptive-innate immune crosstalk. PLoS Pathogens, 2022, 18(11): e1010931 CrossRef
- Duc Hien N., Trung Hoang L., My Quyen T., Phuc Khanh N., Thanh Nguyen L. Molecular characterization of African swine fever viruses circulating in Can Tho City, Vietnam. Veterinary Medicine International, 2023: 8992302 CrossRef
- Goatley L.C., Nash R.H., Andrews C., Hargreaves Z., Tng P., Reis A.L., Graham S.P., Netherton C.L. Cellular and humoral immune responses after immunisation with low virulent African swine fever virus in the large white inbred Babraham line and outbred domestic Pigs. Viruses, 2022, 14(7): 1487 CrossRef
- Sang H., Miller G., Lokhandwala S., Sangewar N., Waghela S.D., Bishop R.P., Mwangi W. Progress toward development of effective and safe African swine fever virus vaccines. Frontiers inVeterinary Science,2020, 7: 84 CrossRef
- Lohse L., Nielsen J., Uttenthal A., Olesen A.S., Strandbygaard B., Rasmussen T.B., Belsham G.J., Botner A. Experimental infections of pigs with African swine fever virus (genotype II); studies in young animals and pregnant sows. Viruses, 2022, 14(7): 1387 CrossRef
- Deutschmann P., Carrau T., Sehl-Ewert J., Forth J.H., Viaplana E., Mancera J.C., Urniza A., Beer M., Blome S. Taking a promising vaccine candidate further: efficacy of ASFV-G-MGF after intramuscular vaccination of domestic pigs and oral vaccination of wild boar. Pathogens, 2022, 11(9): 996 CrossRef
- Ding M., Dang W., Liu H., Zhang K., Xu F., Tian H., Huang H., Shi Z., Sunkang Y., Qin X., Zhang Y., Zheng H. Sequential deletions of interferon inhibitors MGF110-9L and MGF505-7R result in sterile immunity against the Eurasia strain of Africa swine fever. Journal of Virology, 2022, 96(20): e0119222 CrossRef
- Borca M.V., Rai A., Ramirez-Medina E., Silva E., Velazquez-Salinas L., Vuono E., Pruitt S., Espinoza N., Gladue D.P. A cell cultureadapted vaccine virus against the current African swine fever virus pandemic strain. Journal of Virology,2021, 95(14): e00123-21 CrossRef
- Gladue D.P., Ramirez-Medina E., Vuono E., Silva E., Rai A., Pruitt S., Espinoza N., VelazquezSalinas L., Borca M.V. Deletion of the A137R gene from the pandemic strain of African swine fever virus attenuates the strain and offers protection against the virulent pandemic virus. Journal of Virology, 2021, 95(21): e01139-21 CrossRef
- King K., Chapman D., Argilaguet J.M., Fishbourne E., Hutet E., Cariolet R., Hutchings G., Oura C.A., Netherton C.L., Moffat K., Taylor G., Le Potier M.F., Dixon L.K., Takamatsu H.H. Protection of European domestic pigs from virulent African isolates of African swine fever virus by experimental immunisation. Vaccine, 2011, 29(28): 4593-4600 CrossRef
- Gallardo C., Soler A., Nieto R., Sánchez M.A., Martins C., Pelayo V., Carrascosa A., Revilla Y., Simón A., Briones V., Sánchez-Vizcaíno J.M., Arias M. Experimental transmission of African swine fever (ASF) low virulent isolate NH/P68 by surviving pigs. Transboundary and Emerging Diseases, 2015, 62(6): 612-622 CrossRef
- Salguero F.J. Comparative pathology and pathogenesis of African swine fever infection in swine. Frontiers in Veterinary Science, 2020, 7: 282 CrossRef
- Sehl-Ewert J., Deutschmann P., Breithaupt A., Blome S. Pathology of African swine fever in wild boar carcasses naturally infected with German virus variants. Pathogens, 2022, 11(11): 1386 CrossRef
- Howey E.B., O'Donnell V., de Carvalho Ferreira H.C., Borca M.V., Arzt J. Pathogenesis of highly virulent African swine fever virus in domestic pigs exposed via intraoropharyngeal, intranasopharyngeal, and intramuscular inoculation, and by direct contact with infected pigs. Virus Research, 2013, 178(2): 328-339 CrossRef
- Attreed S.E., Silva C., Abbott S., Ramirez-Medina E., Espinoza N., Borca M.V., Gladue D.P., Diaz-San Segundo F. A Highly effective African swine fever virus vaccine elicits a memory T cell response in vaccinated swine. Pathogens, 2022, 11(12): 1438 CrossRef
- Niederwerder M.C., Hefley T.J. Diagnostic sensitivity of porcine biological samples for detecting African swine fever virus infection after natural consumption in feed and liquid. Transboundary and Emerging Diseases, 2022, 69: 2727-2734 CrossRef
- Abkallo H.M., Hemmink J.D., Oduor B., Khazalwa E.M., Svitek N., Assad-Garcia N., Khayumbi J., Fuchs W., Vashee S., Steinaa L. Co-deletion of A238L and EP402R genes from a genotype ix African swine fever virus results in partial attenuation and protection in swine. Viruses, 2022, 14(9): 2024 CrossRef
- Pérez-Núñez D., Sunwoo S.Y., García-Belmonte R., Kim C., Vigara-Astillero G., Riera E., Kim D.M., Jeong J., Tark D., Ko Y.S., You Y.K., Revilla Y. Recombinant African swine fever virus Arm/07/CBM/c2 lacking CD2v and A238L is attenuated and protects pigs against virulent Korean Paju strain. Vaccines, 2022, 10(12): 1992 CrossRef
- Yang H., Peng Z., Song W., Zhang C., Fan J., Chen H., Hua L., Pei J., Tang X., Chen H., Wu B. A triplex real-time PCR method to detect African swine fever virus gene-deleted and wild type strains. Frontiers in Veterinary Science,2022, 9: 943099 CrossRef
- Elnagar A., Blome S., Beer M., Hoffmann B. Point-of-care testing for sensitive detection of the african swine fever virus genome. Viruses, 2022, 14(12): 2827 CrossRef
- Petrov A., Forth J.H., Zani L., Beer M., Blome S. No evidence for long-term carrier status of pigs after African swine fever virus infection. Transboundary and Emerging Diseases, 2018, 65: 1318-1328 CrossRef
- Walczak M., Frant M., Juszkiewicz M., Mazur-Panasiuk N., Szymankiewicz K., Bruczyńska M., Woźniakowski G. Vertical transmission of anti-ASFV antibodies as one of potential causes of seropositive results among young wild boar population in Poland. Polish Journal of Veterinary Sciences, 2020, 23(1): 21-25 CrossRef
- Tran X.H., Phuong L.T.T., Huy N.Q., Thuy D.T., Nguyen V.D., Quang P.H., Ngôn Q.V., Rai A., Gay C.G., Gladue D.P., Borca M.V. Evaluation of the safety profile of the ASFV vaccine candidate ASFV-G-I177L. Viruses, 2022, 14(5): 896 CrossRef
- Friedrichs V., Reicks D., Hasenfuß T., Gerstenkorn E., Zimmerman J.J., Nelson E.A., Carrau T., Deutschmann P., Sehl-Ewert J., Roszyk H., Beer M., Christopher-Hennings J., Blome S. Artificial insemination as an alternative transmission route for African swine fever virus. Pathogens, 2022, 11(12): 1539 CrossRef
- Eblé P.L., Hagenaars T.J., Weesendorp E., Quak S., Moonen-Leusen H.W., Loeffen W.L.A. Transmission of African swine fever virus via carrier (survivor) pigs does occur. Veterinary Microbiology, 2019, 237: 108345 CrossRef
- Liu Y., Xie Z., Li Y., Song Y., Di D., Liu J., Gong L., Chen Z., Wu J., Ye Z., Liu J., Yu W., Lv L., Zhong Q., Tian C., Song Q., Wang H., Chen H. Evaluation of an I177L gene-based five-gene-deleted African swine fever virus as a live attenuated vaccine in pigs. Emerging Microbes & Infections, 2023, 12(1): 2148560 CrossRef
- Kitamura T., Masujin K., Yamazoe R., Kameyama K, Watanabe M., Ikezawa M., Yamada M., Kokuho T. A spontaneously occurring African swine fever virus with 11 gene deletions partially protects pigs challenged with the parental strain. Viruses, 2023, 15(2): 311 CrossRef
- National Research Council (US) Committee for the Update of the Guide for the Care and Use of Laboratory Animals. Guide for the care and use of laboratory animals. Eighth Edition. The National Academies Press, Washington, DC, 2011.
- GOST 28573-90 Svin’i. Metody laboratornoy diagnostiki afrikanskoy chumy sviney [GOST 28573-90 Pigs. Methods of laboratory diagnostics of African swine fever]. Moscow, 2005 (in Russ.).
- Chapter 3.8.1. African swine fever (infection with African swine fever virus). In: Manual of diagnostic tests and vaccines for terrestrial animals. World Organisation for Animal Health (OIE), Paris, France, 2019.
- Ashmarin I.P., Vasil’ev N.N., Ambrosov V.A. Bystrye metody statisticheskoy obrabotki i planirovanie eksperimentov [Rapid statistical methods and design of experiments]. Leningrad, 1974 (in Russ.).
- Hamdy F.M., Dardiri A.H. Clinical and immunologic responses of pigs to African swine fever virus isolated from the Western Hemisphere. American Journal of Veterinary Research,1984, 45(4): 711-714.
- McVicar J.W. Quantitative aspects of the transmission of African swine fever. American Journal of Veterinary Research, 1984, 45(8): 1535-1541.
- Ekue N.F., Wilkinson P.J., Wardley R.C. Infection of pigs with the Cameroon isolate (Cam/82) of African swine fever virus. Journal of Comparative Pathology, 1989, 100(2): 145-154 CrossRef
- de Carvalho Ferreira H.C., Weesendorp E., Elbers A.R., Bouma A., Quak S., Stegeman J.A., Loeffen W.L. African swine fever virus excretion patterns in persistently infected animals: a quantitative approach. Veterinary Microbiology, 2012, 160(3-4): 327-340 CrossRef
- Oura C.A., Powell P.P., Parkhouse R.M. African swine fever: a disease characterized by apoptosis. Journal of General Virology, 1998, 79(6): 1427-1438 CrossRef
- Bourry O., Hutet E., Le Dimna M., Lucas P., Blanchard Y., Chastagner A., Paboeuf F., Le Potier M.F. Oronasal or intramuscular immunization with a thermo-attenuated ASFV strain provides full clinical protection against Georgia 2007/1 challenge. Viruses, 2022, 14: 2777 CrossRef