Peste Des Petits Ruminants Vaccine Research Articles

Flock level socio-economic and other associated risk factors for Peste des petits ruminants (PPR) exposure in sheep and goats in Madhya Pradesh state, India.

To effectively control and eradicate PPR, the comprehensive understanding of risk factors associated with PPR exposure is vital. Hence, this study investigated socioeconomic and other associated risk determinants for PPR exposure at flock level in sheep and goats in a non-vaccination programme implemented Madhya Pradesh state India. A total of 410 sheep and goat flocks, comprised mostly of goats but also some mixed flocks, were surveyed during 2016 using a multistage random sampling procedure. Further, 230 blood samples were also collected from the farmers-reported PPR affected flocks and sera were tested using c-ELISA to confirm PPR exposure. The primary data on socioeconomic factors, farm management factors, health status, vaccination details and other epidemiological risk factors were collected from flock owners and descriptive statistics, chi-square analysis and logistic regression models were fitted to identify the significant risk factors for PPR incidence. The farmer's education, flock size, rearing pattern, and awareness of PPR vaccination were found to be significant pre-disposing risk factors for PPR exposure in the flocks. Hence, the control and eradication strategy need to be designed comprehensively considering the key social factors like education and vaccination awareness along with other flock level risk factors to eradicate PPR by 2030 in consonance with the global plan.

Progress in vaccines against peste des petits ruminants virus

Peste des petits ruminants (PPR) is a highly contagious and economically important viral disease of both domestic (goats and sheep) and wild small ruminants. Due to the devastating effect of this disease on livestock and livelihoods, the Food and Agriculture Organization of the United Nations (FAO) and the World Organization for Animal Health (WOAH) endorsed the Global Strategy for the Control and Eradication of PPR (PPR GCES) and launched the PPR Global Eradication Programme (PPR GEP) to eradicate PPRV by 2030. 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 vaccines are thermolabile and require maintenance of an effective cold chain to deliver to the field. In addition, infected animals cannot be differentiated from vaccinated ones (DIVA). To overcome these limitations, some new generation PPR vaccines have been developed: poxvirus vaccine, positive and negative marker vaccine through reverse genetic approach, chimeric vaccine, anti-idiotypic vaccine, subunit vaccine, virus-like particles vaccine, edible vaccine and combined vaccines. Novel recombinant PPR DIVA vaccines were evaluated in goats for safety and efficacy, and all vaccinated animals were clinically protected against an intranasal PPRV challenge. Furthermore, newly developed ELISAs were capable of differentiating between infected and vaccinated animals. Therefore, these DIVA vaccines and the associated tests can facilitate the serological monitoring process and speed up global PPR eradication through vaccination.

Modeling for Smart Vaccination against Peste des Petits Ruminants (PPR) in the Emirate of Abu Dhabi, United Arab Emirates.

Peste des petits ruminants (PPR) is a contagious and economically important transboundary viral disease of small ruminants. The United Arab Emirates (UAE) national animal health plan aimed to control and eradicate PPR from the country by following the global PPR control and eradication strategy which adopts small ruminants' mass vaccination to eradicate the disease from the globe by 2030. A smart vaccination approach, which is less expensive and has longer-term sustainable benefits, is needed to accelerate the eradication of PPR. In this study, a mathematical algorithm was developed based on animals' identification and registration data, belonging to the Abu Dhabi Agriculture and Food Safety Authority (ADAFSA), and other different parameters related to PPR risk occurrence. The latter included animal holding vaccination history, the number of animals per holding, forecasting of the number of animals and newborns per holding, the proximity of an animal holding to a PPR outbreak and the historical animal holding owner vaccination rejection attitude. The developed algorithm successfully prioritized animal holdings at risk of PPR infection within Abu Dhabi Emirate to be targeted by vaccination. This in turn facilitated the mobilization of field vaccination teams to target specific sheep and goat holdings to ensure the generation of immunity against the disease on a risk-based approach. The vaccination coverage of the targeted livestock population was increased to 86% and the vaccination rejection attitude was reduced by 35%. The duration of the vaccination campaign was reduced to 30 compared to 70 working days and hence can alleviate the depletion of human and logistic resources commonly used in classical mass vaccination campaigns. The results obtained from implementing the algorithm-based PPR vaccination campaign will reduce the negative impact of PPR on the UAE livestock sector and accelerate the achievement of the national PPR eradication plan requirements.

Seroprevalence and risk factors of Peste des petits ruminants in different production systems in Uganda

Peste des petits ruminants (PPR) is a highly contagious and fatal disease of mostly domestic goats and sheep. First reported in Uganda in 2007, the extent of peste des petits ruminants virus (PPRV) exposure, geographical distribution and risk factors of its transmission and spread are not clearly understood. In this study, we used cluster random sampling methodology to select study villages from three districts representing three different production systems along Uganda’s “cattle corridor”. Between October and December 2022, 2520 goat and sheep serum samples were collected from 252 households with no history of PPR vaccination in the past one year. The household heads were interviewed to assess possible risk factors of PPRV transmission using a structured questionnaire. The serum samples were screened with a commercial competitive enzyme-linked immunosorbent assay (cELISA) for PPRV antibodies. The determined overall true seroprevalence of PPRV was 27.3% [95% CI: 25.4–29.1]. The seroprevalence of PPRV antibodies in different production systems was 44.1% [95% CI: 40.6–47.7], 31.7% [95% CI: 28.4–35.0] and 6.1% [95% CI: 4.4–7.9] for pastoral, agropastoral and mixed crop-livestock production systems respectively. A mixed-effects multivariable logistic regression model revealed strong statistical evidence of association between female animals and PPRV antibody seropositivity compared to males [OR= 2.45, 95% CI: 1.7–3.5, p < 0.001]. The likelihood of being PPRV antibody seropositive significantly increased with increasing small ruminant age. Animals older than 3 years were more than three times as likely to be PPRV seropositive compared to animals aged under 1 year [OR= 3.41, 95% CI: 2.39–4.85, p < 0.001]. There was no statistical evidence of association between small ruminant species and PPRV antibody seropositivity (p = 0.423). Village flocks that interacted with neighboring flocks daily during grazing (IRR = 1.59, 95% CI: 1.19–2.13) and watering around swamps (IRR = 1.59, 95% CI: 1.19–2.13) were highly correlated with increased number of PPRV seropositive animals as compared to flocks that were more restricted in grazing and watered around other water sources other than swamps. Flocks from pastoral and agropastoral production systems were more than 10 times more likely to have seropositive animals than mixed crop-livestock flocks. Targeting PPR control interventions (vaccination and livestock movement control) to pastoral and agro-pastoral small ruminant production systems that are very prone to PPR incursions is recommended to prevent PPRV spread to low-risk smallholder mixed crop-livestock production systems.

Assessment of Peste des Petits Ruminants Antibodies in Vaccinated Pregnant Ewes of Kazakh Breed Fine-Fleeced and Determination of the Decreasing Trend of Maternal Immunity in Their Lambs.

In this article, we first assessed peste des petits ruminants (PPR) antibodies in vaccinated pregnant ewes of Kazakh breed fine-fleeced immunized with the PPR vaccine and the duration of maternal immunity in their lambs. Ewes in the last trimester of pregnancy and gestation were immunized with a vaccine from the Nigeria 75/1 strain of the PPR virus (PPRV) produced by the Research Institute of Biological Safety Problems (RIBSP), Kazakhstan. Serum samples from lambs born from vaccinated and unvaccinated ewes were collected a week after birth and at intervals of 7 days for 18 weeks after birth. Serum samples collected from lambs were tested for PPR antibodies using competitive ELISA and virus neutralization test (VNT). Maternal antibodies (MAs) in lambs born from vaccinated ewes were detected for up to 18 weeks, with a tendency to decrease starting at week 14, and by the end of the experiment receded below the protective level (<1:8). In the blood serum of a 14-week-old lamb with MAs (1:8), post vaccination with a field dose (103 TCID50) of the vaccine against PPR, the titers of protective antibodies against PPRV increased to 1:16 on day 14 post vaccination, and the lamb was protected from infection with the field PPRV. A lamb of the same age with MAs in the 1:8 titer was 100% protected from infection with the field PPRV. Therefore, it is recommended that lambs of the Kazakh fine-wool breed be immunized from the age of 14 weeks or older to avoid a period of susceptibility.

Determining the decreasing trend of maternal immunity against small ruminant morbillivirus in goat kids.

Small ruminant morbillivirus (SRMV) is the etiological agent of Peste des petits ruminants (PPR) disease. PPR is one of the most important viral diseases of small ruminant husbandry. In the endemic countries, vaccination is the main way to control this disease. Administering the first PPR vaccine in goat kids requires decreased maternal immunity. The aim of this study was to determine the decreasing trend of maternal immunity against SRMV in goat kids born from vaccinated goats. Twenty Saanen goat kids were studied in two groups including control (n = 5, receiving colostrum from unvaccinated goats) and treatment (n = 15, receiving colostrum from vaccinated goats). Virus neutralisation (VN) test was used to evaluate serum specific antibodies against SRMV in goat kids from birth to 100 days of age. The first goat kid (n = 1) in the treatment group was seronegative at the age of 28 days. All the goat kids were seronegative at the age of 100 days. The average serum titre of the goat kids at the age of 70-100 days became negative. Some goat kids became seronegative before reaching the age of receiving the first PPR vaccine. The age of 70-100 days could be a good age range to give the first dose of PPR vaccine to the goat kids, but more studies were needed on the effectiveness of this vaccine at this age range.

PPR (koyun keçi vebası) ve mavidil aşısının merinos ırkı koyunlarda eş zamanlı uygulanabilirliğinin araştırılması

Abstract: Peste des Petits Ruminants (PPR) and Bluetongue (BT), which are among the contagious animal diseases, cause serious economic losses and are included in the notifiable diseases by the World Organization for Animal Health (WOAH). PPR and BT vaccines are widely used in countries where outbreaks occur. In this study, we aimed to examine the neutralizing antibody response of simultaneously administered PPR and BT serotype 4 vaccines in sheep. For this purpose, a study was performed under field conditions in a state-owned breeding farm. All the experimental animals were confirmed seronegative by serum neutralization test (SNT) for antibodies to the PPR virus (PPRV) and BT virus serotype 4 (BTV4). Subsequently, the experimental animals were divided into four groups. Group 1 (Group 1/PPR; lamb n=10, sheep n=10) and group 2 (Group 2/BTV4; lamb n=10, sheep n=10) were vaccinated separately with the PPR and BTV4 vaccines. Group 3 was vaccinated simultaneously with PPR and BTV4 (Group 3/PPR-BTV4; lamb n=10, sheep n=10). Group 4 was unvaccinated and served as the control. In each of the experimental groups, the vaccinations were carried out only once. Post-vaccination blood samples were collected at intervals of 1, 3, and 6 months. A total of 280 post-vaccination blood serum samples were evaluated with SNT for PPRV and BTV4 neutralizing antibodies. When the neutralizing antibody levels between the groups were compared, group 3 did not show any statistically significant difference (p&gt;0.05) from group 1 and group 2. Based on the antibody response of simultaneous vaccination, it is shown that the simultaneous vaccination could be administered on the field, and could be labor and cost-effective.

Peste des Petits Ruminants (PPR) vaccine R&D investment: financial assessment of vaccine development and administration in India.

The present study assessed the financial viability of Peste des Petits Ruminants (PPR) vaccine Research & Development (R&D) investment in India and the Gross Technology Revenue (GTR) accrual to the different stakeholders. The Net Present Value (NPV), Internal Rate of Return (IRR) and Benefit Cost Ratio (BCR) of PPR vaccine development and administration were USD 16326.6 million (INR 130612 crore), USD 18454.2 million (INR 147633 crore) and USD 21645.6 million (INR 173164 crore); 162.2%, 167.6% and 169.7% and 43.3:1, 48.8:1 and 57.1:1, respectively under low, medium and high disease incidence scenarios. The estimated cumulative GTR accrued during 2001-02 to 2017-18 by the innovating public research institutions (Indian Council of Agricultural Research-Indian Veterinary Research Institute (ICAR-IVRI) and Tamil Nadu Veterinary and Animal Sciences University (TANUVAS)), private vaccine producers, public sector biologicals and government revenues in terms of taxes was USD 0.696 million (INR 5.568 crore) for ICAR-IVRI and USD 0.033 million (INR 0.26 crore) for TANUVAS; USD 5.00 million (INR 40 crore); USD 7.141 million (INR 57.1 crore) and USD 0.671 million (INR 5.36 crore), respectively. Overall, financial benefits of PPR vaccine development and administration to control PPR in India outweighs the investment in manifolds.

Evaluation of monoclonal antibodies in immunofluorescence assay for rapid quality control of Peste des petits ruminants (PPR) vaccine

Peste des petits ruminants (PPR) is an acute viral disease of small ruminants with morbidity and mortality rates as high as 90 % and 100 % respectively. Vaccination using a homologous live-attenuated vaccine is the main control strategy available in endemic countries, and ensuring the quality of these vaccines is of utmost importance for PPR control. Currently, the quality control test to determine vaccine potency is the time-consuming and subjective tissue culture infectious dose (TCID50) assay involving titration on Vero cell line and reading the cytopathic effect (CPE) using light microscopy. In this study, an indirect immunofluorescent antibody test (IFAT) was evaluated for PPR vaccines potency testing. Accuracy and repeatability of the IFAT were also determined. Six PPR vaccine batches were produced and tested simultaneously by CPE reading and the IFAT. Vero cells were seeded in 96-well plates, and infected with 10-fold serial dilutions of the vaccines. CPEs were read continuously from day 3–14 after infection, and titers expressed in TCID50/ml. From 3–7 days post-infection, cells were fixed, incubated with anti-N and anti-H monoclonal antibodies (mAbs), and stained with a secondary antibody labeled with a fluorescent tag. Fluorescent foci of infection were detected using a fluorescence microscope, and titers were calculated as TCID50/ml. The results indicated that from day 4, the IFAT gave similar results to CPE readings of day 14 (intraclass correlation coefficient, ICC = 0.957, P < 0.0001). This is a three-fold reduction in time and can be used for rapid PPR vaccine potency evaluation. However, there was no difference observed between the results of the two mAbs (ICC = 0.910, P < 0.0001) indicating that both are equally sensitive and rapid. This result indicates that the IFAT may be more suited for potency testing of PPR vaccines as it saves time and minimizes analyst-related variability associated with CPE reading.

Economic impact of a peste des petits ruminants outbreak and vaccination cost in northwest Ethiopia.

Peste des petits ruminants (PPR) is an important endemic disease of small ruminants in Ethiopia. While vaccination is widely used in the country to control the disease, quantitative estimates of the actual economic losses due to outbreaks and costs of vaccination are scarce. This study assessed the economic impact and costs of PPR vaccination in Metema district, northwest Ethiopia. The economic impact of the disease was estimated from an outbreak investigation including interviews with 233 smallholder farmers in PPR-affected kebeles (subdistricts). The cost of PPR vaccination was obtained from vaccination programs in six kebeles of the district and from secondary data in the district veterinary office. In the investigated PPR outbreak, animal-level PPR morbidity and mortality rates were 51% and 22%, respectively, in sheep and 51% and 25%, respectively, in goats. The flock level morbidity rate was 83% for sheep flocks and 87% for goat flocks. The mean flock level loss was Ethiopian Birr (ETB) 7835 (USD 329 in 2018 average exchange rate) (95% CI: 5954-9718) for affected sheep flocks and ETB 7136 (USD 300) (95% CI: 5869-8404) for affected goat flocks. The losses in all study flocks during the outbreak were ETB 319 (USD 13.4) per sheep and ETB 306 (USD 12.9) per goat. Mortality accounted for more than 70% of the total losses in both sheep and goat flocks. Vaccination costs for PPR were estimated at ETB 3 per correctly vaccinated animal. Based on the estimated animal-level direct economic losses and vaccination cost, it can be conjectured that vaccination will pay if a district PPR outbreak occurs more than once every 13 years. This does not account for additional benefits from vaccine-derived herd immunity reducing disease burden in the wider population. In conclusion, PPR caused high morbidity and mortality in the affected flocks and resulted in high economic losses, equivalent to 14% of annual household income, dramatically affecting the livelihoods of affected flock owners. The vaccination practised in the district is likely to have a positive economic return, with strengthened vaccination programmes bringing reduced economic impact and improved livelihoods.

Antibody response of sheep to simultaneous vaccination of foot-and-mouth disease, peste des petits ruminants, sheep pox and goat pox, and bluetongue vaccines.

There are many infectious animal diseases in T urkey and generally, vaccination is the primarly control strategy to combat them. However, it is difficult to apply all vaccines in a definite period in the field due to limitations of the labor and finance. Rapid vaccination and effective use of labor can be possible with the help of simultaneous vaccine administrations. The study aims to show the effects of simultaneous foot-and-mouth disease (FMD), peste des petits ruminants (PPR), sheep pox and goat pox (SGP), and bluetongue (BT) vaccine administration on the antibody response of sheep. For this aim, 30 sheep were divided into one experiment and 5 control groups. Blood samples were collected in each group at 0, 30 and 60 days post-vaccination (DPV). Immune response was measured with virus neutralization test (VNT) and, liquid phase blocking ELISA (LPBE) for FMDV; VNT for BTV and PPR. A live virus challenge study was performed to determine the immune response of SGP vaccine. As a result, antibody titers for each vaccine agent decreased on 60 DPV with the simultaneous vaccination except FMD. The difference between means of antibody titer decrease with single and simultaneous vaccinations is significant especially for BTV and PPR vaccines at 60DPV (p<0.05). Briefly, this decreasing immune response of three live vaccines can be explained with the development of the interference, administration of these vaccines from the same injection site, the effect of cytokines, especially IL-10 effect of SGP vaccine. It was concluded that four vaccines can not be used simultaneously in sheep.

Improved vaccination protocol to enhance immunity in lambs of Kuwait farms

The susceptibility of lambs to infective diseases should be minimized by improving the immunity of lambs through effective vaccination procedures to abate lamb mortality in sheep farms. In this regard, field experiments were carried out with 180 pregnant ewes of Naeemi sheep breed at the PAAFR (Public Authority for Agriculture and Fisheries Research Station, Kuwait). The results revealed that the concentration of serum Ig’s in blood samples collected from ewes vaccinated during pregnancy with Pasteurella, Clostridia, FMD (Foot and Mouth Disease) and PPR (Peste des Petits Ruminants) vaccines was significantly elevated as vaccination against these four diseases agents would have ultimately resulted in circulating antibodies protecting the animals against natural exposure. Theconcentration of colostral Ig’s produced by vaccinated ewes during the pregnancy period was significantly (P<0.05) higher than the normal colostrum secreted from unvaccinated ewes during pregnancy, ensuring the positive role of the colostrum in transferring passive immunity. The results clearly illustrated no cases of mortality and abortion, as vaccination has played a role in maintaining the health of ewes by overcoming the targeted pathogens and preventing any abnormalities in the pregnant ewes. The present study confirmed the improved immune status of young lambs born to ewes vaccinated twice during pregnancy, reflecting improved health status. It is recommended to maintain 21 days’ intervals in vaccinating ewes with different vaccines for specific diseases.

Spatio-temporal cluster analysis and transmission drivers for Peste des Petits Ruminants in Uganda.

Peste des Petits Ruminants (PPR) is a transboundary, highly contagious, and fatal disease of small ruminants. PPR causes global annual economic losses of between USD 1.5 and 2.0 billion across more than 70 affected countries. Despite the commercial availability of effective PPR vaccines, lack of financial and technical commitment to PPR control coupled with a dearth of refined PPR risk profiling data in different endemic countries has perpetuated PPR virus transmission. In Uganda, over the past 5 years, PPR has extended from northeastern Uganda (Karamoja) with sporadic incursions in other districts /regions. To identify disease cluster hotspot trends that would facilitate the design and implementation of PPR risk-based control methods (including vaccination), we employed the space-time cube approach to identify trends in the clustering of outbreaks in neighbouring space-time cells using confirmed PPR outbreak report data (2007-2020). We also used negative binomial and logistic regression models and identified high small ruminant density, extended road length, low annual precipitation and high soil water index as the most important drivers of PPR in Uganda. The study identified (with 90-99% confidence) five PPR disease hotspot trend categories across subregions of Uganda. Diminishing hotspots were identified in the Karamoja region whereas consecutive, sporadic, new and emerging hotspots were identified in central and southwestern districts of Uganda. Inter-district and cross-border small ruminant movement facilitated by longer road stretches and animal comingling precipitate PPR outbreaks as well as PPR virus spread from its initial Karamoja focus to the central and southwestern Uganda. There is therefore urgent need to prioritize considerable vaccination coverage to obtain the required herd immunity among small ruminants in the new hotspot areas to block transmission to further emerging hotspots. Findings of this study provide a basis for more robust timing and prioritization of control measures including vaccination.

Women's Empowerment and Livestock Vaccination: Evidence from Peste des Petits Ruminants Vaccination Interventions in Northern Ghana.

Simple SummarySmall ruminants (goat and sheep) are key livestock species in supporting women’s empowerment (WE) in low- and middle-income countries. Animal vaccines are essential for livestock productivity, hence an important means to support WE. WE is, in turn, important for animal vaccine adoption. Little is known, however, of how WE is associated with animal vaccination for women-controlled livestock assets (e.g., goats and sheep). Our analysis explores the link between domains of WE and knowledge of, access to, and use of peste des petits ruminants (PPR) vaccines. Such knowledge can help inform the design of livestock vaccine systems that are better able to reach women and support their empowerment. Using a partial least squares structural equilibrium model (PLS-SEM), we analyzed data collected using the Women’s Empowerment in Livestock Index (WELI) tool from goat keepers in Northern Ghana, which included a module on the PPR vaccine. We found a strong direct positive association between women and men’s knowledge about animal health and PPR vaccination and a strong indirect positive association between access to PPR vaccines and empowerment. Moreover, women and men goat keepers differed in the dimensions of empowerment that the PPR vaccine facets were strongly associated with—asset ownership and input into decisions concerning livestock was significant for women but not for men. Consequently, policy and actions towards enhancing women’s asset ownership, input into decisions about livestock production, knowledge of animal health and vaccines, and access to vaccines are important in designing effective and equitable livestock vaccine systems.Healthy livestock provide meaningful opportunities to enhance women’s empowerment (WE) in low- and middle-income countries. Animal vaccines are important to keep livestock healthy and productive. However, gender-based restrictions limit women’s access to animal health services, thereby affecting the potential of livestock to enhance their empowerment. While growing empirical evidence reveals that women-controlled livestock (e.g., small ruminants) have important implications for WE and support better household nutrition outcomes, little empirical evidence exists from rigorous analyses of the relationship between WE and animal vaccines for women-controlled livestock species. Our analysis explores the relationship between WE and involvement with PPR vaccination in Ghana. Data collected using the Women’s Empowerment in Livestock Index (WELI) tool from 465 women and 92 men farmers (who keep goats) from northern Ghana, and analyzed using PLS-SEM, revealed a significant direct positive association between knowledge about animal health and PPR vaccines and a significant indirect positive association between access to PPR vaccines and empowerment. The empowerment of women goat farmers, as revealed by our model’s results for the relationship between empowerment and vaccine facets, was significantly represented by asset ownership and input into decisions concerning livestock. These study results reveal important considerations in designing effective and equitable livestock vaccine systems.

Who Has Access to Livestock Vaccines? Using the Social-Ecological Model and Intersectionality Frameworks to Identify the Social Barriers to Peste des Petits Ruminants Vaccines in Karamoja, Uganda.

Access to veterinary services is important in Karamoja, northeastern part of Uganda, as livestock is a primary source of livelihood. Gender is often overlooked in animal health programs, let alone intersectionality. However, given the socio-cultural intricacies of Karamoja, ignoring these factors may hinder animal vaccination practices, limiting the success of programs designed to control and prevent animal diseases, such as peste des petits ruminants (PPR). The study used qualitative research methods, including focus group discussions, individual interviews, and key informant interviews in a participatory research approach to investigate the constraints faced by livestock keepers when accessing vaccines. The study was carried out in Abim, Amudat, Kotido, and Moroto, four districts in the Karamoja Subregion of Uganda. A modified version of the socio-ecological model (SEM) blended with an intersectional approach were used as frameworks to analyze underlying individual, social and structural determinants of vaccine access with intersecting factors of social inequalities. The results show there are seven intersecting factors that influence access to vaccination the most. These are: gender, ethnicity, geographic location, age, physical ability, marital status, and access to education. The impact of these intersections across the different levels of the SEM highlight that there are vast inequalities within the current system. Access to vaccines and information about animal health was most limited among women, widows, the elderly, the disabled, geographically isolated, and those with unfavorable knowledge, attitudes, and practices about vaccination. Cultural norms of communities were also important factors determining access to PPR vaccines. Norms that burden women with household chores and beliefs that women cannot manage livestock, combined with gender-based violence, leaves them unable to participate in and benefit from the livestock vaccine value chain. Trainings and sensitization on gendered intersectional approaches for those involved in the distribution and delivery of vaccines are necessary to avoid exacerbating existing inequalities in Karamoja.

Beyond the Gender of the Livestock Holder: Learnings from Intersectional Analyses of PPR Vaccine Value Chains in Nepal, Senegal, and Uganda.

Simple SummaryThe peste des petits ruminants (PPR) is one of the deadliest viral diseases of small ruminants and is endemic in Africa, the Middle East, and Asia. While PPR vaccination programs exist in these contexts, many factors restrict their reach and effectiveness, which go beyond the often cited financial, technological, and logistical constraints. This paper examines these less investigated factors, in particular the role of gender norms and other social and cultural factors, in affecting which livestock keepers are unable to access PPR vaccines and which groups are less reached by the vaccine distribution systems. Across three countries selected for our study, we find that, overall, women derive fewer benefits from the system than men; in addition, belonging to certain ethnic groups, being of low caste, or living in remote regions are additional markers of exclusion and marginalization from accessing livestock vaccines.The peste des petits ruminants (PPR) is a deadly viral disease of small ruminants, which are an important source of livelihood for hundreds of millions of poor smallholders throughout Africa, the Middle East, and Asia. PPR vaccination efforts often focus on overcoming financial, technological, and logistical constraints that limit their reach and effectiveness. This study posits that it is equally important to pay attention to the role of gender and other intersecting social and cultural factors in determining individual and groups’ ability to access PPR vaccines or successfully operate within the vaccine distribution system. We compare three study contexts in Nepal, Senegal, and Uganda. Qualitative data were collected through a total of 99 focus group discussions with men and women livestock keepers and animal health workers, 83 individual interviews, and 74 key informant interviews. Our findings show that there are not only important gender differences, but also interrelated structures of inequalities, which create additional sites of exclusion. However, these intersections are not generalizable across contexts—except for the intersection of gender and geographic remoteness, which is salient across vaccine distribution systems in the three countries—and social markers such as caste, ethnicity, and livelihood are associated with vulnerability only in specific settings. In order to address the distinct needs of livestock keepers in given settings, we argue that an intersectional analysis combined with context-dependent vaccination approaches are critical to achieving higher vaccination rates and, ultimately, PPR disease eradication by 2030.

Preparation of an Inactivated Peste des Petits Ruminants Vaccine and Its Comparative Immunogenicity Evaluation in an Animal Model.

Peste des petits ruminants (PPR) is a highly contagious disease that is considered a major threat to the small livestock industry. Although vaccination via live-attenuated PPR vaccine is a main controlling strategy in the endemic area, during PPR eradication process, the inactivated PPR vaccine (iPPRV) is recommended. This study aimed to compare the inactivation kinetics of the PPR virus via different inactivants and immunogenicity evaluations of the iPPRV formulated vaccine in mice. The vaccinal live PPR virus was inactivated by either H2O2 or binary ethylenimine (BEI (at two concentrations of 1 or 4 mM. Thereafter, the inactivated virus was formulated with different adjuvants, including aluminum hydroxide (AH), aluminum phosphate (AP), and a mixture of AH and AP that were intraperitoneally (IP) administrated (0.1 mL) to 90 BALB/c mice in a completely randomized design and 3×3 factorial arrangement (9 animals per group). The booster vaccination was carried out in all animals 21 days after the primary vaccination. Results showed that the PPR virus was successfully inactivated by all the inactivation agents; however, the time of complete virus inactivation was estimated to be 482, 295, and 495 min post-treatment initiation for 1 mM BEI, 4 mM BEI, and H2O2, respectively. The main effect of inactivant on antibody titers against PPR virus that was measured after 42days post-immunization in mice was significant (P<0.05); however, the adjuvant and interaction effect of inactivator×adjuvant were not effective(P>0.05). Inactivation by 1 mM BEI was associated with a higher antibody titer against PPR virus (P<0.05) in comparison with both 4 mM BEI and H2O2 (2.51 vs. 2.25 and 2.22, respectively). Meanwhile, there were no significant differences among the used adjuvants in terms of eliciting antibody response against PPR virus. In conclusion, the use of 1 mM BEI in combination of AH, AP, or a mixture of AH and AP was associated with a higher immune response against PPR virus in mice. However, the appropriate inactivation kinetic of the virus and immunogenicity associated with the use of H2O2, as well as its biocompatibility property and better cost-benefit, nominated H2O2 to be used in iPPR preparation; however, more investigations are required in target animals.

Duration of Protective Immunity in Sheep Vaccinated with a Combined Vaccine against Peste des Petits Ruminants and Sheep Pox.

In this study, the ability of the combined vaccine against peste des petits ruminants (PPR) (Nigeria strain 75/1) and sheep pox (SPP) (NISKhI strain) to form a protective immune response for 12 months in Kazakh breed fine-fleeced sheep aged 6–12 months was demonstrated. The duration of the protective immunity of immunized sheep from PPR and from SPP was evaluated using a serum neutralization test (SNT), followed by testing of the resistance of vaccinated sheep to infection with the field strain Kentau-7 of the PPRV and the virulent strain A of the SPPV. The PPR antibody response was additionally measured by c-ELISA. A single immunization of sheep with a combined vaccine in a volume of 2.0 mL, containing the PPR and SPP vaccine viruses in the titers of 103.0 TCID50/mL, provided reliable protection of animals from two infections simultaneously for 12 months (observation period). At the same time, in sheep immunized with the combined vaccine, antibodies of PPRV persisted for up to 12 months, with slight fluctuations. The combined vaccine induced 100% clinical protection against the field strain of PPRV and the virulent strain of SPPV in immunized sheep for up to 12 months, while unvaccinated animals became ill with the manifestation of clinical signs specific to PPRV and SPPV.

The influence of intranasal peste des petits ruminants (PPR) vaccine administration alone or with phytogenic mucoadhesive delivery system on PPR outbreak outcomes in goats

ABSTRACT This study reports the influence of peste des petits ruminants (PPR) vaccination on the clinico-pathological outcomes of PPR in the face of an outbreak. Twenty-two West African dwarf goats procured for a different study started showing early signs of PPR during acclimatization. In response, PPR vaccine was administered either intranasally with phytogenic mucoadhesive gum (Group A; n = 6) or without gum (Group B; n = 6); subcutaneously (Group C; n = 6) or not vaccinated (Group D; n = 4) and studied for 21 days. The clinical scores, hematology, serology and pathology scores were evaluated. Clinical signs of PPR were present in all groups, presenting a percentage mortality of 33%; 33%; 64% and 100% for Groups A, B, C, and D, respectively. Polycythemia and mild leukopenia were observed in all groups, and all animals were seropositive by day 7 post-vaccination. The lung consolidation scores were low in Groups A and B, compared to Group C. Histopathological lesions consistent with PPR was observed in the lymphoid organs, gastrointestinal tract, and lungs with the presence of PPR antigen as detected by immunohistochemistry. The findings suggest that intranasal vaccination with or without mucoadhesive gum may influence the outcome of PPR infection more than the subcutaneous route in the face of an outbreak.

Progress towards Eradication of Peste des Petits Ruminants through Vaccination.

Peste des petits ruminants (PPR) is a transboundary viral disease that threatens more than 1.74 billion goats and sheep in approximately 70 countries globally. In 2015, the international community set the goal of eradicating PPR by 2030, and, since then, Food and Agriculture Organization of the United Nations (FAO) and World Organization for Animal Health (OIE) have jointly developed and implemented the Global Control and Eradication Strategy for PPR. Here, data from the United Nations Food and Agriculture Organization Statistical Database (FAOSTAT), the OIE World Animal Health Information System (WAHIS), Regional Roadmap Meetings, and countries’ responses to PPR Monitoring and Assessment Tool (PMAT) questionnaires were analyzed to inform on current progress towards PPR eradication. OIE recorded the use of over 333 million doses of vaccine in 12 countries from 2015 to 2018, 41.8% of which were used in Asia and 58.2% in Africa. Between 2015 and 2019, a total of 12,757 PPR outbreaks were reported to OIE: 75.1% in Asia, 24.8% in Africa, and 0.1% in Europe. The number of global outbreaks in 2019 fell to 1218, compared with 3688 in 2015. Analysis of vaccine use and PPR outbreaks in countries indicates that disease control strategies, particularly vaccination campaigns and vaccine distribution strategies, still require scientific evaluation. It is imperative that vaccination is undertaken based on the epidemiology of the disease in a region and is coordinated between neighboring countries to restrict transboundary movements. Strengthening surveillance and post-vaccination sero-monitoring at the national level is also essential. The PPR vaccine stock/bank established by FAO, OIE, and other partners have improved the quality assurance and supply of vaccines. However, to achieve PPR eradication, filling the funding gap for vaccination campaigns and other program activities will be critical.