scholarly journals Safety and efficacy of ChAdOx1 RVF vaccine against Rift Valley fever in pregnant sheep and goats

npj Vaccines ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Anna Stedman ◽  
Daniel Wright ◽  
Paul J. Wichgers Schreur ◽  
Madeleine H. A. Clark ◽  
Adrian V. S. Hill ◽  
...  

Abstract Rift Valley fever virus (RVFV) is a zoonotic mosquito-borne virus that was first discovered in Kenya in 1930 and has since spread to become endemic in much of Africa and the Arabian Peninsula. Rift Valley fever (RVF) causes recurrent outbreaks of febrile illness associated with high levels of mortality and poor outcomes during pregnancy—including foetal malformations, spontaneous abortion and stillbirths—in livestock, and associated with miscarriage in humans. No vaccines are available for human use and those licensed for veterinary use have potential drawbacks, including residual virulence that may contraindicate their use in pregnancy. To address this gap, we previously developed a simian adenovirus vectored vaccine, ChAdOx1 RVF, that encodes RVFV envelope glycoproteins. ChAdOx1 RVF is fully protective against RVF in non-pregnant livestock and is also under development for human use. Here, we now demonstrate that when administered to pregnant sheep and goats, ChAdOx1 RVF is safe, elicits high titre RVFV neutralizing antibody, and provides protection against viraemia and foetal loss, although this protection is not as robust for the goats. In addition, we provide a description of RVFV challenge in pregnant goats and contrast this to the pathology observed in pregnant sheep. Together, our data further support the ongoing development of ChAdOx1 RVF vaccine for use in livestock and humans.

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Deo B. Ndumu ◽  
Barnabas Bakamutumaho ◽  
Edward Miller ◽  
Jesca Nakayima ◽  
Robert Downing ◽  
...  

Abstract Background Prior to the first recorded outbreak of Rift Valley fever (RVF) in Uganda, in March 2016, earlier studies done until the 1970’s indicated the presence of the RVF virus (RVFV) in the country, without any recorded outbreaks in either man or animals. While severe outbreaks of RVF occurred in the neighboring countries, none were reported in Uganda despite forecasts that placed some parts of Uganda at similar risk. The Ministry of Agriculture, Animal Industry and Fisheries (MAAIF) undertook studies to determine the RVF sero-prevalence in risk prone areas. Three datasets from cattle sheep and goats were obtained; one from retrospective samples collected in 2010–2011 from the northern region; the second from the western region in 2013 while the third was from a cross-sectional survey done in 2016 in the south-western region. Laboratory analysis involved the use of the Enzyme Linked Immunosorbent Assays (ELISA). Data were subjected to descriptive statistical analyses, including non-parametric chi-square tests for comparisons between districts and species in the regions. Results During the Yellow Fever outbreak investigation of 2010–2011 in the northern region, a total sero-prevalence of 6.7% was obtained for anti RVFV reacting antibodies (IgG and IgM) among the domestic ruminant population. The 2013 sero-survey in the western region showed a prevalence of 18.6% in cattle and 2.3% in small ruminants. The 2016 sero-survey in the districts of Kabale, Kanungu, Kasese, Kisoro and Rubirizi, in the south-western region, had the respective district RVF sero-prevalence of 16.0, 2.1, 0.8, 15.1and 2.7% among the domestic ruminants combined for this region; bovines exhibited the highest cumulative sero-prevalence of 15.2%, compared to 5.3 and 4.0% respectively for sheep and goats per species for the region. Conclusions The absence of apparent outbreaks in Uganda, despite neighboring enzootic areas, having minimal restrictions to the exchange of livestock and their products across borders, suggest an unexpected RVF activity in the study areas that needs to be unraveled. Therefore, more in-depth studies are planned to mitigate the risk of an overt RVF outbreak in humans and animals as has occurred in neighboring countries.


Author(s):  
Mehmet Kale ◽  
Sibel Hasircioglu ◽  
Özlem Özmen ◽  
Nuri Mamak ◽  
Sibel Gür ◽  
...  

In this study, Rift Valley Fever Virus (RVFV) infection was searched serologically and pathologically in cattle (178 Holstein), sheep (160 native), goats (66 ordinary goats, 98 Honamli goats, 16 Saanen goats) with an abortion history and in unborn cattle (8), sheep (24) and goat (5) fetus. Samples were collected between July 2009 and September 2010. As a result of studying specific antibodies to RVFV by using the c-ELISA method in blood serum samples collected from cattle, sheep and goats suffering abortion, seropositivity was identified in 7 cattle (7/178; 3.93%), 4 sheep (4/160;2.50%) and 18 goats (18/180;10.0%). 18 seropositive goats were distributed according to race as 13 ordinary goats (19.70%), 2 Honamli goats (2.04%) and 3 Saanen goats (18.75%). When liver, spleen and brain samples of the unborn fetus of cattle, sheep and goats were studied histopathologically, no pathological findings on RVFV disease were obtained. Consequently, in this study, where RVFV infection in cattle, sheep and goats raised in Western Mediterranean Region of Turkey was serologically revealed, it was concluded that RVFV did not take place in the aetiology of abortion cases in relevant species. 


2016 ◽  
Vol 3 (4) ◽  
Author(s):  
Boushab Mohamed Boushab ◽  
Fatima Zahra Fall-Malick ◽  
Sidi El Wafi Ould Baba ◽  
Mohamed Lemine Ould Salem ◽  
Marie Roseline Darnycka Belizaire ◽  
...  

Abstract Background Rift Valley Fever epizootics are characterized by numerous abortions and mortality among young animals. In humans, the illness is usually characterized by a mild self-limited febrile illness, which could progress to more serious complications.Objectives. The aim of the present prospective study was to describe severe clinical signs and symptoms of Rift Valley Fever in southern Mauritania. Patients and methods Suspected cases were enrolled in Kiffa (Assaba) and Aleg (Brakna) Hospital Centers from September 1 to November 7, 2015, based on the presence of fever, hemorrhagic or meningoencephalitic syndromes, and probable contact with sick animals. Suspected cases were confirmed by enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase-polymerase chain reaction (RT-PCR). Results There were thirty-one confirmed cases. The sex ratio M/F and the average age were 2.9 and 25 years old [range, 4-70 years old], respectively. Mosquito bites, direct contact with aborted or dead animals, and frequent ingestion of milk from these animals were risk factors observed in all patients. Hemorrhagic and neurological manifestations were observed in 81% and 13% of cases, respectively. The results of laboratory analysis showed high levels of transaminases, creatinine, and urea associated with thrombocytopenia, anemia, and leukopenia. All patients who died (42%) had a hemorrhagic syndrome and 3 of them had a neurological complication. Among the cured patients, none had neurologic sequelae. Conclusion The hemorrhagic form was the most common clinical manifestation of RVF found in southern Mauritania and was responsible for a high mortality rate. Our results justify the implementation of a continuous epidemiological surveillance.


2009 ◽  
Vol 137 (9) ◽  
pp. 1309-1318 ◽  
Author(s):  
M. T. HEISE ◽  
A. WHITMORE ◽  
J. THOMPSON ◽  
M. PARSONS ◽  
A. A. GROBBELAAR ◽  
...  

SUMMARYRift Valley fever virus (RVFV) is a mosquito-transmitted bunyavirus (genusPhlebovirus) associated with severe disease in livestock and fatal encephalitis or haemorrhagic fever in a proportion of infected humans. Although live attenuated and inactivated vaccines have been used in livestock, and on a limited scale in humans, there is a need for improved anti-RVFV vaccines. Towards this goal, Sindbis virus replicon vectors expressing the RVFV Gn and Gc glycoproteins, as well as the non-structural nsM protein, were constructed and evaluated for their ability to induce protective immune responses against RVFV. These replicon vectors were shown to produce the RVFV glycoproteins to high levelsin vitroand to induce systemic anti-RVFV antibody responses in immunized mice, as determined by RVFV-specific ELISA, fluorescent antibody tests, and demonstration of a neutralizing antibody response. Replicon vaccination also provided 100% protection against lethal RVFV challenge by either the intraperitoneal or intranasal route. Furthermore, preliminary results indicate that the replicon vectors elicit RVFV-specific neutralizing antibody responses in vaccinated sheep. These results suggest that alphavirus-based replicon vectors can induce protective immunity against RVFV, and that this approach merits further investigation into its potential utility as a RVFV vaccine.


2016 ◽  
Vol 6 (1) ◽  
pp. 31343 ◽  
Author(s):  
Anne-Lie Blomström ◽  
Isabelle Scharin ◽  
Hedvig Stenberg ◽  
Jaquline Figueiredo ◽  
Ofélia Nhambirre ◽  
...  

2020 ◽  
Vol 41 (1) ◽  
pp. 28
Author(s):  
John Bingham ◽  
Petrus Jansen van Vuren

Rift Valley fever (RVF) is a mosquito-borne viral disease, principally of ruminants, that is endemic to Africa. The causative Phlebovirus, Rift Valley fever virus (RVFV), has a broad host range and, as such, also infects humans to cause primarily a self-limiting febrile illness. A small number of human cases will also develop severe complications, including haemorrhagic fever, encephalitis and visual impairment. In parts of Africa, it is a major disease of domestic ruminants, causing epidemics of abortion and mortality. It infects and can be transmitted by a broad range of mosquitos, with those of the genus Aedes and Culex thought to be the major vectors. Therefore, the virus has the potential to become established beyond Africa, including in Australia, where competent vector hosts are endemic. Vaccines for humans have not yet been developed to the commercial stage. This review examines the threat of this virus, with particular reference to Australia, and assesses gaps in our knowledge that may benefit from research focus.


1978 ◽  
Vol 80 (2) ◽  
pp. 183-196 ◽  
Author(s):  
R. Swanepoel ◽  
N. K. Blackburn ◽  
S. Efstratiou ◽  
J. B. Condy

SUMMARYBrains, spleens and livers of 2212 murids, 27 shrews and 7 dormice, trapped at 7 sites in Rhodesia, were tested in 277 pools for the presence of Rift Valley Fever virus. There were no isolations of Rift Valley Fever, but 69 isolations of an unidentified virus were obtained. Sixteen out of 867 sera had low-titre haemagglutination-inhibition activity against Rift Valley Fever antigen, but only one out of 1260 sera had neutralizing antibody. The evidence suggests that murids fail to encounter infection in nature and are unlikely to play a role in circulation and dissemination of Rift Valley Fever virus. Four out of seven widely distributed species of murid, Rhabdomys pumilio, Saccostomys campestris, Aethomys chrysophilus and Lemniscomys griselda, were shown to be capable of circulating amounts of virus likely to be infective for mosquitoes.


2019 ◽  
Vol 86 (1) ◽  
Author(s):  
Georges M. Tshilenge ◽  
Mfumu L.K Mulumba ◽  
Gerald Misinzo ◽  
Rob Noad ◽  
William G. Dundon

Rift Valley fever (RVF) is a zoonotic viral disease caused by the RVF phlebovirus (RVFV) that infects a variety of animal species including sheep and goats. Sera (n = 893) collected between 2013 and 2015 from randomly selected indigenous sheep and goats in seven provinces of the Democratic Republic of the Congo (DRC) were tested for the presence of specific immunoglobulin G (IgG) and M (IgM) against RVFV, using two commercially available enzyme-linked immunosorbent assays. The reverse transcription polymerase chain reaction (RT-PCR) was also used to detect RVFV nucleic acid. There was significant variation in true seroprevalence of RVFV for both sheep and goats between the seven provinces investigated. Values ranged from 0.0 (95% confidence interval [CI] 0.0–6.55) to 23.81 (95% CI 12.03–41.76) for goat and 0.0 (95% CI 0.0–7.56) to 37.11 (95% CI 15.48–65.94) for sheep, respectively. One serum (1.85%) out of 54 that tested positive for IgG was found to be IgM-positive. This same sample was also positive by RT-PCR indicating an active or recent infection. These findings report the presence of RVFV in small ruminants in the DRC for the first time and indicate variations in exposure to the virus in different parts of the country.


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