Long-term sterilizing immunity to rinderpest in cattle vaccinated with a recombinant vaccinia virus expressing high levels of the fusion and hemagglutinin glycoproteins

Thermostable Vaccines in Veterinary Medicine: State of the Art and Opportunities to Be Seized

The COVID-19 pandemic has highlighted the weakness of the vaccine supply chain, and the lack of thermostable formulations is one of its major limitations. This study presents evidence from peer-reviewed literature on the development of thermostable vaccines for veterinary use. A systematic review and meta-analysis were performed to evaluate the immunogenicity and/or the efficacy/effectiveness of thermostable vaccines against infectious diseases. The selected studies (n = 78) assessed the vaccine’s heat stability under different temperature conditions and over different periods. Only one study assessed the exposure of the vaccine to freezing temperatures. Two field studies provided robust evidence on the immunogenicity of commercial vaccines stored at temperatures far in excess of the manufacturer’s recommended cold-chain conditions. The drying process was the most-used method to improve the vaccine’s thermostability, along with the use of different stabilizers. The pooled vaccine efficacy was estimated to be high (VE = 69%), highlighting the importance of vaccination in reducing the economic losses due to the disease impact. These findings provide evidence on the needs and benefits of developing a portfolio of heat- and freeze-stable veterinary vaccines to unleash the true potential of immunization as an essential component of improved animal health and welfare, reduce the burden of certain zoonotic events and thus contribute to economic resilience worldwide.

Assessment of the control measures of category A diseases of the Animal Health Law: Infection with rinderpest virus (Rinderpest)

EFSA received a mandate from the European Commission to assess the effectiveness of control measures against diseases included in the Category A list according to Regulation (EU) 2016/429 on transmissible animal diseases ('Animal Health Law'). This opinion belongs to a series of opinions where these control measures are assessed, with this opinion covering the assessment of control measures for rinderpest (RP), the only animal disease to have been globally eradicated. In this opinion, the AHAW Panel reviewed the effectiveness of: (i) clinical and laboratory sampling procedures, (ii) monitoring period and (iii) the minimum radius of the protection and surveillance zone, and the minimum length of time the measures should be applied in these zones. The general methodology used for this series of opinions has been published elsewhere. The transmission kernels used for the assessment of the minimum radius of the protection and surveillance zones are shown. Several scenarios for which control measures had to be assessed were agreed prior to the assessment. Considering that RP has been eradicated globally, a re-emergence that is not stopped in its early phases could have a devastating impact on animal health and the economy. The panel concludes that no suitable strategies are available to entirely mitigate the risk associated with granting derogations from killing of animals in an affected establishment or for animal movements. Therefore, the panel recommends to not grant any derogations. The monitoring period of 21 days was assessed as effective, except for the hypothetical first re-emergence of RP, when lack of awareness and diagnostic capability may extend the time to detection. It was concluded that the protection and the surveillance zones would contain 90% and > 99%, respectively, of the infections from an affected establishment. Enlarging the protection zone to 4 km would contain the disease spread with 95% probability.

Replication-inducible vaccinia virus vectors with enhanced safety in vivo

Vaccinia virus (VACV) has been used extensively as the vaccine against smallpox and as a viral vector for the development of recombinant vaccines and cancer therapies. Replication-competent, non-attenuated VACVs induce strong, long-lived humoral and cell-mediated immune responses and can be effective oncolytic vectors. However, complications from uncontrolled VACV replication in vaccinees and their close contacts can be severe, particularly in individuals with predisposing conditions. In an effort to develop replication-competent VACV vectors with improved safety, we placed VACV late genes encoding core or virion morphogenesis proteins under the control of tet operon elements to regulate their expression with tetracycline antibiotics. These replication-inducible VACVs would only express the selected genes in the presence of tetracyclines. VACVs inducibly expressing the A3L or A6L genes replicated indistinguishably from wild-type VACV in the presence of tetracyclines, whereas there was no evidence of replication in the absence of antibiotics. These outcomes were reflected in mice, where the VACV inducibly expressing the A6L gene caused weight loss and mortality equivalent to wild-type VACV in the presence of tetracyclines. In the absence of tetracyclines, mice were protected from weight loss and mortality, and viral replication was not detected. These findings indicate that replication-inducible VACVs based on the conditional expression of the A3L or A6L genes can be used for the development of safer, next-generation live VACV vectors and vaccines. The design allows for administration of replication-inducible VACV in the absence of tetracyclines (as a replication-defective vector) or in the presence of tetracyclines (as a replication-competent vector) with enhanced safety.

Advances in peste des petits ruminants vaccines

Peste des petits ruminants (PPR) is a highly contagious disease of small ruminants that leads to high morbidity and mortality thereby results in devastating economic consequences to the livestock industry. PPR is currently endemic across most parts of Asia and Africa, the two regions with the highest concentration of poor people in the world. Sheep and goats in particularly contribute significantly towards the upliftment of livelihood of the poor and marginal farmers in these regions. In this context, PPR directly affecting the viability of sheep and goat husbandry has emerged as a major hurdle in the development of these regions. The control of PPR in these regions could significantly contribute to poverty alleviation, therefore, the Office International des Epizooties (OIE) and Food and Agricultural Organization (FAO) have targeted the control and eradication of PPR by 2030 a priority. In order to achieve this goal, a potent, safe and efficacious live-attenuated PPR vaccine with long-lasting immunity is available for immunoprophylaxis. However, the live-attenuated PPR vaccine is thermolabile and needs maintenance of an effective cold chain to deliver into the field. In addition, the infected animals cannot be differentiated from vaccinated animals. To overcome these limitations, some recombinant vaccines have been developed. This review comprehensively describes about the latest developments in PPR vaccines.

Protective efficacy of a single immunization with capripoxvirus-vectored recombinant peste des petits ruminants vaccines in presence of pre-existing immunity

Sheeppox, goatpox and peste des petits ruminants (PPR) are highly contagious ruminant diseases widely distributed in Africa, the Middle East and Asia. Capripoxvirus (CPV)-vectored recombinant PPR vaccines (rCPV-PPR vaccines), which have been developed and shown to protect against both Capripox (CP) and PPR, would be critical tools in the control of these important diseases. In most parts of the world, these disease distributions overlap each other leaving concerns about the potential impact that pre-existing immunity against either disease may have on the protective efficacy of these bivalent rCPV-PPR vaccines. Currently, this question has not been indisputably addressed. Therefore, we undertook this study, under experimental conditions designed for the context of mass vaccination campaigns of small ruminants, using the two CPV recombinants (Kenya sheep-1 (KS-1) strain-based constructs) developed previously in our laboratory. Pre-existing immunity was first induced by immunization either with an attenuated CPV vaccine strain (KS-1) or the attenuated PPRV vaccine strain (Nigeria 75/1) and animals were thereafter inoculated once subcutaneously with a mixture of CPV recombinants expressing either the hemagglutinin (H) or the fusion (F) protein gene of PPRV (10(3) TCID50/animal of each). Finally, these animals were challenged with a virulent CPV strain followed by a virulent PPRV strain 3 weeks later. Our study demonstrated full protection against CP for vaccinated animals with prior exposure to PPRV and a partial protection against PPR for vaccinated animals with prior exposure to CPV. The latter animals exhibited a mild clinical form of PPR and did not show any post-challenge anamnestic neutralizing antibody response against PPRV. The implications of these results are discussed herein and suggestions made for future research regarding the development of CPV-vectored vaccines.

IL-18 expression results in a recombinant vaccinia virus that is highly attenuated and immunogenic

Interferon-γ (IFN-γ) is an attenuating factor for vaccinia virus (VACV), decreasing its virulence in vivo by more than a million fold. It is also a highly effective adjuvant when administered at the time of immunization with protein antigens. However, recombinant VACV (rVACV) vaccines expressing IFN-γ do not induce enhanced immune responses. It is possible that the IFN-γ expressed by rVACVs induces both an antiviral state and increased immunological clearance, thus resulting in decreased levels of antigen expression due to reduced viral replication and spread. We conjectured that delaying expression of IFN-γ would result in enhanced production of antigens by rVACVs thus resulting in increased immune responses to foreign antigens. Interleukin (IL)-18, also known as IFN-γ inducing factor, is a cytokine that induces T and NK cells to produce IFN-γ. In this study, we demonstrated that an rVACV expressing bioactive murine IL-18 replicated to low but detectable levels in vivo, unlike an rVACV expressing IFN-γ. Moreover, the rVACV expressing IL-18 was significantly attenuated in both immunocompromised and immunocompetent mice. This attenuation was dependent on IFN-γ, as IL-18 expression failed to attenuate VACV in IFN-γ knock-out mice. Cytotoxic T-cell (CTL) and anamnestic antibody responses were slightly increased in animals vaccinated with the rVACV expressing IL-18. Thus, induction of IFN-γ because of IL-18 expression resulted in an rVACV that replicated to low but detectable levels in vivo, yet elicited slightly better CTL and anamnestic humoral immune responses.

Recombinant adenovirus expressing the haemagglutinin of Peste des petits ruminants virus (PPRV) protects goats against challenge with pathogenic virus; a DIVA vaccine for PPR

Peste des petits ruminants virus (PPRV) is a morbillivirus that can cause severe disease in sheep and goats, characterised by pyrexia, pneumo-enteritis, and gastritis. The socio-economic burden of the disease is increasing in underdeveloped countries, with poor livestock keepers being affected the most. Current vaccines consist of cell-culture attenuated strains of PPRV, which induce a similar antibody profile to that induced by natural infection. Generation of a vaccine that enables differentiation of infected from vaccinated animals (DIVA) would benefit PPR control and eradication programmes, particularly in the later stages of an eradication campaign and for countries where the disease is not endemic. In order to create a vaccine that would enable infected animals to be distinguished from vaccinated ones (DIVA vaccine), we have evaluated the immunogenicity of recombinant fowlpox (FP) and replication-defective recombinant human adenovirus 5 (Ad), expressing PPRV F and H proteins, in goats. The Ad constructs induced higher levels of virus-specific and neutralising antibodies, and primed greater numbers of CD8⁺ T cells than the FP-vectored vaccines. Importantly, a single dose of Ad-H, with or without the addition of Ad expressing ovine granulocyte macrophage colony-stimulating factor and/or ovine interleukin-2, not only induced strong antibody and cell-mediated immunity but also completely protected goats against challenge with virulent PPRV, 4 months after vaccination. Replication-defective Ad-H therefore offers the possibility of an effective DIVA vaccine.

Recombinant DNA technology for producing new rinderpest virus vaccines

With few exceptions, vaccination aims to control rather than eliminate or eradicate disease. The eradication of smallpox in the 1970s led to two other human diseases, polio and measles, being targeted for eradication by the World Health Organization. In general, animal diseases are ignored by the public, however, recent targeting of the rinderpest virus, the agent of cattle plague, has put this virus on the verge of global extinction. For centuries, this virus was responsible for major cattle plagues in Europe, Asia and Africa. The success of the Global Rinderpest Eradication Program is an illustration of the power of vaccines to alter people's lives economically and socially when used in an internationally coordinated way. In this review, the history of the development of rinderpest vaccines and the new research being undertaken to produce marker vaccines, using recombinant DNA technology and reverse genetics, are described. In addition, the valuable contribution that marker vaccines can make in the final stages of the rinderpest eradication program is outlined.

A vaccinia virus renaissance: new vaccine and immunotherapeutic uses after smallpox eradication

In 1796, Edward Jenner introduced the concept of vaccination with cowpox virus, an Orthopoxvirus within the family Poxviridae that elicits cross protective immunity against related orthopoxviruses, including smallpox virus (variola virus). Over time, vaccinia virus (VACV) replaced cowpox virus as the smallpox vaccine, and vaccination efforts eventually led to the successful global eradication of smallpox in 1979. VACV has many characteristics that make it an excellent vaccine and that were crucial for the successful eradication of smallpox, including (1) its exceptional thermal stability (a very important but uncommon characteristic in live vaccines), (2) its ability to elicit strong humoral and cell-mediated immune responses, (3) the fact that it is easy to propagate, and (4) that it is not oncogenic, given that VACV replication occurs exclusively within the host cell cytoplasm and there is no evidence that the viral genome integrates into the host genome. Since the eradication of smallpox, VACV has experienced a renaissance of interest as a viral vector for the development of recombinant vaccines, immunotherapies, and oncolytic therapies, as well as the development of next-generation smallpox vaccines. This revival is mainly due to the successful use and extensive characterization of VACV as a vaccine during the smallpox eradication campaign, along with the ability to genetically manipulate its large dsDNA genome while retaining infectivity and immunogenicity, its wide mammalian host range, and its natural tropism for tumor cells that allows its use as an oncolytic vector. This review provides an overview of new uses of VACV that are currently being explored for the development of vaccines, immunotherapeutics, and oncolytic virotherapies.

Recombinant vaccines against the mononegaviruses--what we have learned from animal disease controls

The mononegaviruses include a number of highly contagious and severe disease-causing viruses of both animals and humans. For the control of these viral diseases, development of vaccines, either with classical methods or with recombinant DNA virus vectors, has been attempted over the years. Recently reverse genetics of mononegaviruses has been developed and used to generate infectious viruses possessing genomes derived from cloned cDNA in order to study the consequent effects of viral gene manipulations on phenotype. This technology allows us to develop novel candidate vaccines. In particular, a variety of different attenuation strategies to produce a range of attenuated mononegavirus vaccines have been studied. In addition, because of their ideal nature as live vaccines, recombinant mononegaviruses expressing foreign proteins have also been produced with the aim of developing multivalent vaccines against more than one pathogen. These recombinant mononegaviruses are currently under evaluation as new viral vectors for vaccination. Reverse genetics could have great potential for the preparation of vaccines against many mononegaviruses.

Recombinant Rift Valley fever vaccines induce protective levels of antibody in baboons and resistance to lethal challenge in mice

Rift Valley fever (RVF) is a zoonotic disease endemic in Africa and the Arabian Peninsula caused by the highly infectious Rift Valley fever virus (RVFV) that can be lethal to humans and animals and results in major losses in the livestock industry. RVF is exotic to the United States; however, mosquito species native to this region can serve as biological vectors for the virus. Thus, accidental or malicious introduction of this virus could result in RVFV becoming endemic in North America. Such an event would likely lead to significant morbidity and mortality in humans, and devastating economic effects on the livestock industry. Currently, there are no licensed vaccines for RVF that are both safe and efficacious. To address this issue, we developed two recombinant RVFV vaccines using vaccinia virus (VACV) as a vector for use in livestock. The first vaccine, vCOGnGc, was attenuated by the deletion of a VACV gene encoding an IFN-γ binding protein, insertional inactivation of the thymidine kinase gene, and expression of RVFV glycoproteins, Gn and Gc. The second vaccine, vCOGnGcγ, is identical to the first and also expresses the human IFN-γ gene to enhance safety. Both vaccines are extremely safe; neither resulted in weight loss nor death in severe combined immunodeficient mice, and pock lesions were smaller in baboons compared with the controls. Furthermore, both vaccines induced protective levels of antibody titers in vaccinated mice and baboons. Mice were protected from lethal RVFV challenge. Thus, we have developed two safe and efficacious recombinant vaccines for RVF.

Identification of an intergenic region that is not essential for replication of goatpox virus

A recombinant goatpox virus was constructed in which an enhanced green fluorescent protein gene was inserted under the control of the 11K late promoter, a guanine phosphoribosyltransferase gene was inserted under the control of the 7.5K early/late promoter, and exogenous genes were inserted into an intergenic region between loci gp_24 and gp_24.5 of the recombinant genome. Analysis of protein expression showed that LT cells infected with only the recombinant virus produced specific fluorescence. A comparative growth assay demonstrated the stability of the recombinant virus at the replication level. These results suggest that the intergenic region is not essential for replication of goatpox virus.

MVA recombinants expressing the fusion and hemagglutinin genes of PPRV protects goats against virulent challenge

Peste des Petits Ruminants (PPR) is a highly contagious animal disease caused by the Peste des Petits Ruminants virus (PPRV) belonging to the genus morbillivirus and family Paramyxoviridae. The disease results in high morbidity and mortality in goats, sheep and in some small wild ruminants. The presence of large number of small ruminants reared in endemic areas makes PPR a notorious disease threatening the livelihood of poor farmers. Conventional vaccination using a live, attenuated vaccine gives adequate protection but cannot be used in case of eradication of the disease due to difficulty in differentiation of infected animals from the vaccinated ones.In the present study, we constructed two recombinant viruses using attenuated Modified Vaccinia virus Ankara virus (MVA) namely MVA-F and MVA-H expressing the full length PPRV fusion (F) and hemagglutinin (H) glycoproteins, respectively. Goats were vaccinated intramuscularly with 105 plaque forming units (PFU) each of the recombinant viruses and a live attenuated vaccine (RAKSHA PPR) and challenged 4 months later with PPRV challenge virus (10(3) goat LD(50)). All goats were completely protected from the clinical disease. This study gave an indication that mass vaccination of small ruminants with either of the above or both recombinant inexpensive virus vaccines could help in possible eradication of PPRV from endemic countries like India and subsequent seromonitoring of the disease for differentiation of infected animals from vaccinated ones.

Antigen delivery systems for veterinary vaccine development. Viral-vector based delivery systems

The recent advances in molecular genetics, pathogenesis and immunology have provided an optimal framework for developing novel approaches in the rational design of vaccines effective against viral epizootic diseases. This paper reviews most of the viral-vector based antigen delivery systems (ADSs) recently developed for vaccine testing in veterinary species, including attenuated virus and DNA and RNA viral vectors. Besides their usefulness in vaccinology, these ADSs constitute invaluable tools to researchers for understanding the nature of protective responses in different species, opening the possibility of modulating or potentiating relevant immune mechanisms involved in protection.

Lower levels of gamma interferon expressed by a pseudotyped single-cycle simian immunodeficiency virus enhance immunogenicity in rats

A vaccine for human immunodeficiency virus (HIV) infection is desperately needed to control the AIDS pandemic. To address this problem, we constructed single-cycle simian immunodeficiency viruses (SIVs) pseudotyped with the glycoprotein of vesicular stomatitis virus and expressing different levels of gamma interferon (IFN-gamma) as a potential vaccine strategy. We previously showed that IFN-gamma expression by pseudotyped SIVs does not alter viral single-cycle infectivity. T cells primed with dendritic cells transduced by pseudotyped SIVs expressing high levels of IFN-gamma had stronger T-cell responses than those primed with dendritic cells transduced by constructs lacking IFN-gamma. In the present study, we tested the immunogenicities of these pseudotyped SIVs in a rat model. The construct expressing low levels of rat IFN-gamma (dSIV(LRgamma)) induced higher levels of cell-mediated and humoral immune responses than the construct lacking IFN-gamma (dSIV(R)). Rats vaccinated with dSIV(LRgamma) also had lower viral loads than those vaccinated with dSIV(R) when inoculated with a recombinant vaccinia virus expressing SIV Gag-Pol as a surrogate challenge. The construct expressing high levels of IFN-gamma (dSIV(HRgamma)) did not further enhance immunity and was less protective than dSIV(LRgamma). In conclusion, the data indicated that IFN-gamma functioned as an adjuvant to augment antigen-specific immune responses in a dose- and cell type-related manner in vivo. Thus, fine-tuning of the cytokine expression appears to be essential in designing vaccine vectors expressing adjuvant genes such as the gene for IFN-gamma. Furthermore, we provide evidence of the utility of the rat model to evaluate the immunogenicities of single-cycle HIV/SIV recombinant vaccines before initiating studies with nonhuman primate models.

Vaccinia viruses with a serpin gene deletion and expressing IFN-gamma induce potent immune responses without detectable replication in vivo

In a continuing effort to develop safe and efficacious vaccine and immunotherapeutic vectors, we constructed recombinant vaccinia virus (rVV) vaccines lacking either the B13R (SPI-2) or the B22R (SPI-1) immune-modulating gene and coexpressing IFN-gamma. B13R and B22R are nonessential VV immune-modulating genes that have antiapoptotic and antiinflammatory properties with sequence homology to serine protease inhibitors (serpins). IFN-gamma is a cytokine with potent immunoregulatory, antineoplastic, and antiviral properties. We observed that these rVVs with a deletion in a serpin gene and expressing IFN-gamma replicated to high titers in tissue culture yet were avirulent in both immunocompromised and immunocompetent mice with no detectable viral replication in these animals. A single immunization elicited potent humoral, T helper, and cytotoxic T cell immune responses in mice despite the absence of any detectable virus replication in vivo. IFN-gamma coexpression and the inactivation of one or more VV immune-modulating genes provide an optimized method for increasing the safety while maintaining the efficacy of rVV vaccines. This strategy provides a method for developing highly safe and efficacious vaccines for smallpox and other diseases and immunotherapeutic vectors.

Cytotoxic T cell epitope in cattle from the attachment glycoproteins of rinderpest and peste des petits ruminants viruses

The surface glycoproteins of rinderpest virus (RPV) confer protective immunity in cattle. We demonstrated that cattle immunized with a recombinant extracellular baculovirus expressing the hemagglutinin (H) protein of RPV (rECV-H) generate virus neutralizing antibody responses, bovine leukocyte antigen (BoLA) class II restricted helper T cell responses and BoLA class I restricted cytotoxic T cell (CTL) responses against RPV-H and hemagglutinin-neuraminidase (HN) glycoprotein of closely related Peste des petits ruminants virus (PPRV). In this study, employing autologous skin fibroblasts transiently expressing truncations of H and HN in a BoLA class I restricted lymphoproliferation assay, we have mapped a highly homologous domain (amino acids 400-423) on these proteins harboring a CTL epitope. Subsequently, based on sequence comparison with available BoLA class I binding motifs, we have identified a BoLA-A11 binding motif (amino acids 408-416) in the stimulatory domain. Autologous cells pulsed with a synthetic peptide corresponding to this sequence stimulated CTLs from rECV-H immunized as well as tissue culture attenuated RPV vaccinated cattle of different breeds and parentage. This is the first epitope identified in cattle on the attachment glycoproteins of RPV and PPRV.

Systemic and oral immunogenicity of hemagglutinin protein of rinderpest virus expressed by transgenic peanut plants in a mouse model

Rinderpest causes a devastating disease, often fatal, in wild and domestic ruminants. It has been eradicated successfully using a live, attenuated vaccine from most part of the world leaving a few foci of disease in parts of Africa, the Middle East, and South Asia. We have developed transgenic peanut (Arachis hypogaea L.) plants expressing hemagglutinin (H) protein of rinderpest virus (RPV), which is antigenically authentic. In this work, we have evaluated the immunogenicity of peanut-expressed H protein using mouse model, administered parenterally as well as orally. Intraperitoneal immunization of mice with the transgenic peanut extract elicited antibody response specific to H. These antibodies neutralized virus infectivity in vitro. Oral immunization of mice with transgenic peanut induced H-specific serum IgG and IgA antibodies. The systemic and oral immunogenicity of plant-derived H in absence of any adjuvant indicates the potential of edible vaccine for rinderpest.

Monoclonal antibody-based competitive ELISA for simultaneous detection of rinderpest virus and peste des petits ruminants virus antibodies

An experimental competitive enzyme-linked immunosorbent assay (morbillivirus cELISA) using a recombinant N antigen (rRPV N) expressed in a baculovirus and a ruminant morbillivirus (RPV and PPRV)-specific monoclonal antibody (P-13A9) was developed for simultaneous detection of rinderpest virus (RPV) and peste des petits ruminants virus (PPRV) antibodies and its diagnostic performance was evaluated. A set of known reference antisera against RPV and PPRV belonging to different lineages, experimental sera from cattle vaccinated for a RPV of Asian lineage, and field sera from cattle and sheep/goat populations known to be positive (West Africa) and negative (Korea) for RPV and PPRV were used for the evaluation. Morbillivirus cELISA results on the panel of experimental RPV and PPRV antisera showed high correlation (r=0.97) between the whole virus and the rRPV N antigens, suggesting that the rRPV N contains a ruminant morbillivirus-specific antigenic determinant recognized by the P-13A9 and it may be suitable as an ELISA antigen in place of the whole virus. Morbillivirus cELISA detected anti-RPV and anti-PPRV antibodies in all reference RPV and PPRV antisera containing VN titers >/=1:8, suggesting that the assay can simultaneously detect antibodies against RPV and PPRV. Anti-RPV antibody was detected by morbillivirus cELISA in vaccinated cattle as early as the VNT and continued to be detectable by both the cELISA and the VNT until termination of the study. When applied to field samples from Africa, morbillivirus cELISA showed good agreement with a RP cELISA kit (kappa value of 0.86) in bovine sera and with a peste des petits ruminant cELISA kit (kappa value of 0.81) in caprine/ovine sera. Usefulness of morbillivirus cELISA using the rRPV N protein was discussed.

Oral immunization of cattle with hemagglutinin protein of rinderpest virus expressed in transgenic peanut induces specific immune responses

Rinderpest is an acute, highly contagious often fatal disease of large and small ruminants, both domestic and wild. Global eradication of rinderpest needs a robust, safe and cost-effective vaccine. The causative agent, rinderpest virus (RPV) is an important member of the genus Morbillivirus in the Paramyxoviridae family. We have generated transgenic peanut (Arachis hypogea L.) plants expressing hemagglutinin protein of RPV and report here, the induction of immune responses in cattle following oral feeding with transgenic leaves expressing hemagglutinin protein without oral adjuvant. Hemagglutinin-specific antibody was detected in the serum as confirmed by immunohistochemical staining of virus-infected cells, and in vitro neutralization of virus infectivity. Oral delivery also resulted in cell-mediated immune responses.

Rinderpest

Rinderpest, also known as cattle plague, was for centuries the most dreaded bovine plague known and one that changed the course of history and still seriously compromises trade. It can lay waste not only to farming communities but the wildlife heritage of countries also is threatened because its broad host spectrum extends across cattle, Asian buffaloes, yaks, and many other artiodactyls, both domesticated and wild, including swine. This article provides a brief history of rinderpest before describing its clinical, pathologic, epidemiologic, and diagnostic features. In dealing with control, the prospects for total eradication are described in the context of the Global Rinderpest Eradication Programme, which is on target to achieve that goal by 2010--the first time that an animal disease will have been eradicated.