Publications by authors named "M Elharrak"

21 Publications

Safety and efficacy of a Bluetongue inactivated vaccine (serotypes 1 and 4) in sheep.

Vet Microbiol 2021 Oct 20;261:109212. Epub 2021 Aug 20.

Research and Development, MCI Santé Animale, Lot. 157, Z. I., Sud-Ouest (ERAC) B.P: 278, Mohammedia 28810, Morocco. Electronic address:

A new inactivated vaccine against Bluetongue virus (BTV) serotypes 1 and 4, was developed from field isolates. Safety and efficacy of the vaccine were evaluated in sheep by serological monitoring and virus nucleic acid detection after experimental infection of vaccinated animals. Seroconversion was observed in vaccinated animals at day 14 post vaccination (pv) with neutralizing antibody titer of 1.9 and 1.8 for serotypes 1 and 4, respectively. The titer increase significantly after the booster reaching 2.7 and persist one year >1.5 for both serotypes. After challenge with virulent isolates, vireamia was recorded in control animals, as evident by q-PCR with threshold cycles (Ct) ranging from 24 to 31 and peaked at day 10 post challenge, while no vireamia was detected in vaccinated animals. Vaccinated sheep were fully protected against the disease and infection.
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http://dx.doi.org/10.1016/j.vetmic.2021.109212DOI Listing
October 2021

Long term immunity against Peste Des Petits Ruminants mediated by a recombinant Newcastle disease virus vaccine.

Vet Microbiol 2021 Oct 5;261:109201. Epub 2021 Aug 5.

Research and Development, MCI Santé Animale, Lot. 157, Z. I., Sud-Ouest (ERAC) B.P: 278, Mohammedia, 28810, Morocco. Electronic address:

Peste des Petits Ruminants (PPR) is a highly contagious and often fatal disease of sheep and goats. Conventional live vaccines have been successfully used in endemic countries however, there are not completely safe and not allowing differentiation between vaccinated and infected animals (DIVA). In this study, a recombinant Newcastle disease virus (NDV) expressing the hemagglutinin of PPRV (NDV-PPRVH) was evaluated on small ruminants by serology response in sheep and goats, experimental infection in goats and immunity duration in sheep. The NDV-PPRVH vaccine injected twice at 28 days' interval, provided full protection against challenge with a virulent PPR strain in the most sensitive species and induced significant neutralizing antibodies. Immunological response in goats was slightly higher than sheep and the vaccine injected at 10 50 % egg infective dose/mL allowed anti-PPRV antibodies that lasted at least 12 months as shown by antibody response monitoring in sheep. The NDV vector presented a limited replication in the host and vaccinated animals remained negative when tested by cELISA based on PPRV nucleoprotein allowing DIVA. This recombinant vaccine appears to be a promising candidate in a free at risk countries and may be an important component of the global strategy for PPR eradication.
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http://dx.doi.org/10.1016/j.vetmic.2021.109201DOI Listing
October 2021

Draft Genome Sequence of the Capripoxvirus Vaccine Strain KSGP 0240, Reisolated from Cattle.

Microbiol Resour Announc 2021 Jul 29;10(30):e0044021. Epub 2021 Jul 29.

Research and Development Department, Multi-Chemical Industry, Mohammedia, Morocco.

Control of lumpy skin disease in cattle is based on vaccination with live attenuated vaccines. The Kenyan strain KSGP 0240 is commonly used to vaccinate ruminants against capripox infections, but the conferred protection is still controversial. In this study, we report the draft genome sequence of the vaccine strain KSGP 0240, reisolated from cattle.
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http://dx.doi.org/10.1128/MRA.00440-21DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8320456PMC
July 2021

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

Vaccines (Basel) 2021 Jun 8;9(6). Epub 2021 Jun 8.

MCI Santé Animale, Mohammedia 28810, Morocco.

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.
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http://dx.doi.org/10.3390/vaccines9060621DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8226854PMC
June 2021

Comparative sensitivity study of primary cells, vero, OA3.Ts and ESH-L cell lines to lumpy skin disease, sheeppox, and goatpox viruses detection and growth.

J Virol Methods 2021 07 14;293:114164. Epub 2021 Apr 14.

Laboratory of Research and Development virology, MCI Animal Health, Lot. 157, Zone Industrielle Sud-Ouest (ERAC) B.P: 278, 28810 Mohammedia, Morocco.

Lumpy skin disease virus (LSDV), sheeppox virus (SPPV) and goatpox (GTPV) virus have been usually grown on primary cells for diagnosis, production and titration purposes. The use of primary cells present several inconvenient, heavy preparation, heterogeneous cell population, non-reproducible viral titration and presence of potential endogenous contaminants. Therefore investigating sensitivity of candidate continuous cell lines is needed. In this study, we compared the above Capripox viruses (CaPVs) sensitivity of primary cells of four origin (heart, skin, testis and kidney), with three cell lines (Vero, OA3.Ts and ESH-L). We tested sensitivity for virus isolation, replication cycle and titration, revealed by cytopathic effect (CPE), immunoenzymatic staining and immunofluorescence. Our results show that ESH-L cells and primary fetal heart cells present the highest sensitivity for CaPVs growth and detection. Vero cells can replicate those viruses but without showing any CPE while the titer obtained on OA3.Ts is lower than primary and ESH-L cells. ESH-L cells are an effective alternative to primary cells use for growing Capripoxviruses and their diagnosis.
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http://dx.doi.org/10.1016/j.jviromet.2021.114164DOI Listing
July 2021
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