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

Abstract

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 16,326.6 million (INR 130,612 crore), USD 18,454.2 million (INR 147,633 crore) and USD 21,645.6 million (INR 173,164 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.

Sheep and goats rearing is the mainstay of rural population in India. As per the livestock census 2019, the total sheep and goat population in India was 74.26 million and 148.88 million, respectively. Peste des Petits Ruminants (PPR) is one of the highly contagious and economically important transboundary viral disease of sheep and goats, with mortality and morbidity rates as high as 90% and 100%, respectively [11].The disease is manifested by severe pyrexia, ocular-nasal discharges, necrotizing and erosive stomatitis, enteritis and pneumonia (Supplementary Fig. 1). In India, PPR was first reported in Tamil Nadu state during 1987 [20] and later reported in other states. Now, PPR is enzootic in India and outbreaks occur in sheep and goats regularly throughout the country, and is a major constraint in small ruminant production incurring great economic losses [5, 6, 11]. The annual loss due to PPR in India is approximately Indian Rupees (INR) 16,110 million at the 10% annual disease incidence level [12]. A national-wide serosurvey in sheep and goats during 2017–2018 by PPR competitive ELISA showed wide variations of PPR seroprevalence/immune population in the different states in India due to variation in vaccination and disease levels with a baseline seroprevalence between 32.4 to 46.11% [6].

Considering the devastating nature of the disease and threat to the sheep and goat rearing farmers livelihood, three live attenuated PPR vaccines (Sungri 96, Arasur 87 and, Coimbatore 97 Vaccine) were developed in India [19]. The Sungri 96 strain (isolate of goat origin) was used by Indian Council of Agricultural Research (ICAR)-Indian Veterinary Research Institute (ICAR-IVRI) and Arasur 87 (isolate of sheep origin) and Coimbatore 97 strain (isolate of goat origin) were used by Tamil Nadu Veterinary and Animal Sciences University (TANUVAS), Chennai, Tamil Nadu for developing the homologous PPR vaccine. The Arasur 87 strain vaccine developed by TANUVAS had supplied vaccines to Tamil Nadu, Andhra Pradesh, Karnataka and Odisha states from 2000–01 to 2005–06 (personal communication). The Sungri 96 strain vaccine developed by IVRI had undergone extensive field testing in 11 states and suppled vaccines to 15 states in India for field use from 2002–2006 [19, 22] and is being widely used in many states and also part of the National Control Programme on PPR (PPR-CP) implemented by the Government of India (GoI) since 2010–11 [5, 6].The experimental vaccine was produced and supplied to various states for vaccination during the initial stages of vaccine development but later PPR vaccine production and quality control technology has been commercialized and transferred to national and multinational companies in India and the state government owned veterinary biological production units for mass production and use. In India, focused vaccination against PPR was practiced from 2002 to 2010, whereas, during 2010–11, PPR-CP using mass vaccination strategy with 100% vaccination of risk population in the first year followed by 30% bi-annual vaccination in the subsequent years to cover the naïve population was implemented in southern states [5, 6].

India had made strides in agricultural Research and Development (R&D) despite a limited investment (0.4% share in Agricultural Gross Domestic Product (AgGDP) during 2008) [17]. The investment in livestock disease preventing technologies like vaccine development has multiplier effects and supports various stakeholders’ viz. farmers, vaccine innovators, vaccine producers and governments. The open access policy in India for the transfer of R&D products from public institutions through commercialization had also paved way for public-private partnership and transfer of technology. It is always necessary to evaluate the R&D impact of the developed technologies to convince the policymakers on the importance of the R&D program in preventive technologies like vaccine development in improving the livelihood of millions of smallholder farmers. The economic surplus approach has been used to assess the R&D impact in agriculture and livestock [13] as the methodology is simple and needs less information, but has severe limitation. Some of the conceptual problems like value judgements which is insurmountable [1, 18].

In India, the impact studies on livestock vaccine development and administration are limited except a study by Bardhan et al. (2017) [7] on PPR which is not comprehensive and has certain major limitations viz., considered only point estimated PPR incidence; assumed 50% vaccination coverage in the country; considered only one institute research cost as investment; meat supply increase was the only benefits of PPR vaccination; and not accounted the sero-monitoring and surveillance cost. Hence, the present study comprehensively assessed the financial viability [10] of R&D investment in PPR vaccine by including all the stages of R&D in India with appropriate field data under with and without vaccination scenarios. In addition, the study estimated the Gross Technology Revenue (GTR) accrued to vaccine developing institutions, the vaccine producing public (Government) veterinary biologicals, the private vaccine producing companies and the government to understand the comprehensive impact of investment in vaccine development and administration to control PPR in India.

MATERIALS AND METHODS

Population projection

The livestock population census in India is available only for the quinquennial period viz., 1992, 1997, 2003, 2007, 2012 and 2019. Hence, to calculate the sheep and goat population each year from 1996–97 to 2025–26 (In India, financial year is represented for the period 1st April to 31st March of next year, hence one year is represented as 1996–97/2025–26), interpolation method was employed using Compound Annual Growth Rate (CAGR). Less than four months sheep and goat population is not vaccinated against PPR [5, 27], hence this age group population was not considered to calculate vaccination cost. Sheep and goat population data for less than four-months age group was not directly available from livestock census and hence 30% of up to 1-year age group was assumed as four-months age group (as per 20th livestock census 2019, 37% constitute up to one-year age group, of which, 30% was considered were under less than four-month age group) and calculated as below;

Number of < 4 months old animals=Total sheep and goats projected population × 0.37 × 0.3.

Vaccine development and Implementation stages

In the present study, based on discussion with the PPR vaccine development scientists, the period 1996–97 to 2002–03 was considered as a vaccine development stage (it includes testing and final release of vaccine for field use). From 2003–04 till 2025–26 is considered as the field implementation stage (vaccination against PPR). The field implementation stage is further categorized into ‘focused vaccination’ stage (2003–04 to 2009–10) through vaccine supply from vaccine innovating research institutes and PPR control programme stage {vaccination stage (2010–11 to 2022–23) and post control program surveillance and monitoring stage (2023–24 to 2025–26)} through the supply of vaccines and diagnostic kits from Government Veterinary Biologicals and authorized private companies.

Vaccination coverage data and strategy

The secondary data on vaccination coverage from 2003–04 to 2020–21 in different states of India was collected. The vaccination data was available for all the states and union territories (UT’s) of India except Jammu and Kashmir, West Bengal and Andaman and Nicobar Islands. In India, focused vaccination was implemented in many states since 2003–04 and control programme mode (PPR-CP) since 2010–11 in southern states. Hence, for financial assessment, from 2003–04 to 2020–21, the actual PPR vaccination administered to sheep and goats in different states in India and from 2021–22 the planned future vaccination strategy {100% vaccination for three years (2021–22 to 2023–24) and 10% need based/ minimal vaccination coverage for two years (2024–25 to 2025–26)} was considered.

PPR incidence levels

The PPR incidence levels under with and without vaccination intervention scenarios is essential to evaluate the financial viability of R&D investment. The actual disease incidence in India before the vaccine development was not available and hence 8% incidence reported in literature [3, 12] in the non-vaccination implemented Madhya Pradesh state during 2008–09 was considered till the year of vaccine development for with and without vaccination scenarios (from 1996–97 to 2003–04). For the period 2004–05 to 2025–26, the disease incidence under with vaccination scenario (after implementation of focused vaccination and PPR-CP mode) was calculated based on the actual vaccination coverage during the period. The vaccination coverage and the PPR incidence is inversely related [23] and hence for calculating decline in PPR incidence under with vaccination scenario from 2004–05 to 2025–26, the average vaccination coverage rate was considered to reduce from the 8% base incidence level (before vaccine development). From 2021–22 to 2023–24, as per draft national strategic plan 100% sheep and goat population [6] will be vaccinated and as a result the disease incidence will be negligible during this period. Under without vaccination scenario, from 2004–05 to 2025–26, a conservative level of three possible incidences 10%, 12% and 15% were considered (Fig. 1). The three possible incidences referred to 8% incidence during 2003–04 increases and reaches to 10%/ 12%/ 15% by 2025–26 under without vaccination scenario (Fig. 1). The incidence levels in between years were interpolated linearly based on incidence in initial year (8%) and final year (10% or 12% or 15%). The difference between projected incidence under without vaccination and with vaccination in different years, were considered to estimate the disease avoided costs/benefits due to PPR vaccine development and administration in India.

Fig. 1.

Represents different Peste des Petits Ruminants (PPR) disease incidence levels from 1996–97 to 2025–26 in India. The three possible incidences refer to 8% disease incidence level increases and reaches 10% (low), 12% (medium) and 15% (high) by 2024–25 under without vaccination scenario.

Benefit stream

To estimate the benefits of PPR vaccine development and administration for each year, difference in disease incidence under with and without vaccination scenarios, the projected risk population in the respective year, per animal disease cost (mortality loss, body weight reduction loss, distress sale loss, treatment cost and opportunity cost of labor per animal), morbidity and mortality levels, vaccination effectiveness (80%) and vaccination coverage were considered. The incidence, disease cost, morbidity, mortality and distress sale proportions were calculated from the primary surveys undertaken in different states of India (Karnataka, Madhya Pradesh, Chhattisgarh and Odisha) by the authors during 2015–20. An annual deflation of 3% (from 1996–97 to 2019–20) and inflation rate (from 2021–22 to 2025–26) was applied as per Jones et al. (2016) [14] to calculate disease cost per animal at 2020–21 prices. The detailed methodology followed in estimating the disease cost was as per the earlier reports [12].

The various components of disease cost were calculated and summed up each year to derive the disease avoidance benefits for different years. Further, the benefits were projected from 1996–97 to 2025–26, by compounding (from 1996–97 to 2019–20) and discounting (from 2025–26 to 2021–22) at 5% rate [14] to adjust the Net Present Value (NPV) at 2020–21 prices. The total benefit of vaccination against PPR was calculated as below,

$B_v\text{=}{\displaystyle \sum _{i\text{=1}}^n\{[({(\Delta I)}_i\ast P_i)\{(M{p}_i\ast L{m}_i)+(W{p}_i\ast L{w}_i)+(D{p}_i\ast D{l}_i)+T{c}_i+O{c}_i\}]\}\ast V{E}_i}$

Where, Bv=Total benefits of vaccination/PPR avoidance cost (USD); (ΔI) i=Difference in PPR incidence under with and without vaccination scenarios in ith year (%); Pi=Projected population in ith year (No.); Mpi=Proportion of mortality due to PPR in ith year (%); Lmi=average mortality loss per animal in ith year (USD); Wpi=Morbidity proportion due to PPR in the ith year (%); Lwi=Average body weight reduction loss per animal in the PPR recovered animal in ith year (USD); Dpi=Distress sale proportion due to PPR in ith year (%); Dli=Average distress sale loss per animal in ith year (USD); Tci=Average treatment cost per animal in ith year (USD); Oci=Average opportunity cost of labour per animal in ith year (USD); VEi=Vaccination effectiveness in ith year (80%) and n=number of years (i=1, 2, 3, …n) (from 1996–97 to 2025–26). Other minor loss associated with PPR (0.36% of the total loss constitute direct wool loss in sheep, 2.01% constitute direct milk loss in goats and loss due reproductive failure constitute 4.91% in sheep and 9.37% in goats) were calculated based on the earlier report [21, 22]. These estimated loss components were summed up in the benefit stream for each year to derive the possible benefits of PPR control through vaccination.

Cost stream

PPR vaccine development cost: The vaccine development is generally involving isolation of the agent, vaccine development, vaccine quality testing, vaccine evaluation and field testing. Each of the stages involves 1–2 years depending on the manpower and other facilities available. The investment made for vaccine development is available only for the ‘evaluation phase’ for indigenous PPR vaccine (Sungri 96 strain) developed by IVRI and hence the same amount of investment is assumed for all other phases of vaccine development. Further, the cost incurred by TANUVAS for developing PPR vaccine using the Arasur 87 and Coimbatore 97 vaccine strains was not available and hence the cost incurred for Sungri 96 [8] was assumed for TANUVAS strains also.

PPR vaccine administration cost: It includes vaccine cost and vaccination logistics and accessories cost. The vaccine cost was calculated based on the number of doses vaccinated and cost per dose. The vaccination logistics and accessories cost includes expenditure towards accessories (needles, syringes, etc.), payment for hired vaccinators, vaccination storage and transportation, cost towards sensitization and technical workshops, extension awareness materials, programme dissemination and publication, strengthening of district laboratories, staff salary, etc. [12]. The vaccination logistics and accessories cost varied depending on the vaccination strategy adopted viz., PPR-CP mode or as a focused vaccination. In PPR-CP implemented states, the vaccination and accessories cost under programme mode reported in literature [12] was employed, whereas for the rest of the states, where vaccination is being practiced as focused/routine vaccination by the veterinarian, the cost was assumed as twice the vaccine cost (arrived based on discussion with the field veterinarian). In India, till 2010, focused PPR vaccination was adopted in all the states and hence from 2003–04 to 2009–10, the vaccination and logistics cost was twice the vaccine cost. In southern states of India including Chhattisgarh state, the vaccination was undertaken in programme mode hence from 2010–11 to 2020–21, the vaccination and logistics cost was programme mode cost and for rest of the states, twice the vaccine cost. Officially, GoI extended the PPR-CP in all the states since 2014–15, but many states had not implemented the programme till 2016–17 and hence the total vaccination and accessories cost considered was for focused or routine vaccination cost till 2017–18 and from 2018–19 to 2025–26, for all the states, the programme mode cost was considered.

Surveillance and monitoring cost: The surveillance and monitoring cost is part of the PPR-CP. The number of PPR diagnostic kits (PPR sandwich ELISA kit and PPR competitive ELISA kit) supplied by ICAR-IVRI from 2004–05 to 2018–19 [2] was considered for diagnostic kit cost calculation. Using each PPR c-ELISA kit 500 serum samples can be tested and hence cost of kit was converted to diagnostic cost per sample and further with expert’s opinion, 15% of the kit cost was considered as testing cost per sample. As per national strategic plan for control and eradication of PPR, sero- surveillance during 2019–20 with approximately 3,200 samples per state or UT’s and sero-monitoring every year till 2022–23 with 1,000 samples per state or UT’s have been planned and accordingly the total cost of sero-surveillance and sero-monitoring were calculated. Furthermore, during the post control phase, active clinical surveillance for detection of virus with ELISA kits as well as other sensitive diagnostics (e.g. RT-PCR) need to be undertaken and accordingly the active clinical surveillance costing was calculated by assuming 20 outbreaks/year (10% reported outbreaks during 2019 [6] was considered) during 2023–24 to 2025–26 with testing of 25 samples per outbreak. The total budget/ programme cost was compounded and discounted at 5% [14] to adjust the net present value during 2020–21. The total cost stream for the respective year is calculated and summed up as below,

$C_v\text{=}{\displaystyle \sum _{i\text{=1}}^n(V{d}_i+V{c}_i+K{c}_i+S{c}_i+A{s}_i+(V_n{}_i\ast V_p{}_i))}$

Where, Cv=Total cost of vaccination (USD); Vdi=Vaccine development cost in the ith year (USD); Vci=Vaccination logistics and accessories cost in the ith year (USD); Kci=Cost of PPR diagnostic kit (USD); Sci=Sero-surveillance and sero-monitoring cost in the ith year (USD); Asi=Active clinical surveillance cost in the ith year (USD); Vni=Number of animal vaccinated in the ith year; Vpi=Price per dose in ith year and n=Number of years from 1996–97 to 2025–26 (i=1,2,3, …n).

Financial assessment of PPR control: The financial viability of R&D investment in PPR vaccine development and the administration to control PPR in India was evaluated based on Benefit Cost (BCR) ratio, Net Present Value (NPV), Internal Rate of Return (IRR) as per standard procedure [10, 12].

Gross Technology Revenue (GTR): Out of three PPR vaccines, the vaccine developed by IVRI has been commercialized and sold to oligopoly veterinary vaccine producing industries in India, which includes private vaccine producing companies and public biologicals of state governments. The private companies provide fixed license fee [15] for using the technology for vaccine production as well as royalty fee whereas the public biologicals provide the fixed license fee. In the initial stage of PPR vaccine development, TANUVAS and IVRI, produced the experimental vaccines and supplied to various state veterinary departments whereas in the later stages, it was licensed to private and state government managed veterinary biological institutions for mass production. Thus the vaccine innovators have generated revenue by selling the PPR vaccines in the initial stages and later through license and royalty fee. The data on the PPR vaccine production, average sale price, royalty fee and taxes paid in different years from the vaccine producing companies in India viz., M/s Indian Immunologicals Ltd., Hyderabad, India; M/s Bio-Med Private limited, Ghaziabad, India, Hester Biosciences Limited, Ahmedabad, India, Brilliant Bio pharma private Limited, Hyderabad and Intervet India Pvt. Ltd. (MSD Animal Health), Pune, India were collected. Out of five private vaccine producing companies contacted, Intervet India Pvt. Ltd. (MSD Animal Health) stated that they had shut down their manufacturing operations and Brilliant bio-pharma informed that commercial production of PPR vaccines had not started during the data collection period (i.e. March 2017). Further, the vaccine production and supply data from two government veterinary biologicals {Telangana State Veterinary Biologicals and Research Institute (TSVBRI), Hyderabad and Institute of Animal Health and Veterinary Biologicals (IAHVB), Kerala} were collected. The number of vaccination undertaken by the Karnataka State Animal Husbandry Department was considered as proxy for vaccine production by Institute of Animal health and Veterinary Biological (IAH&VB), Government of Karnataka. Further, the supply of vaccines by the vaccine innovating research institutions viz., ICAR-IVRI (2002 to 2010) and TANUVAS (2001 to 2006) was collected (personal communication) to calculate the GTR accrued to these institutions. The GTR was calculated based on the doses sold/supplied multiplied by the market price in the respective year. Some private and government biologicals had not indicated the sale price for few years, for which, the market price (INR 1.82/dose) [12] prevailed during 2015–16 were discounted to calculate the GTR in the respective year.

The revenue generated by the vaccine developing institution after commercialization includes licensing fee and royalty fees. The data on license fee paid by some of the PPR vaccine technology procured companies/institutions was not available and for these companies the magnitude of peer company’s license fee was considered. Further, the royalty fee paid by some of the companies was not available and it was assumed as three per cent of the gross revenue realized from PPR vaccine sale. Further, the government earned sales tax and service tax paid by the PPR vaccine producing companies and institutions till the June 2017. For some companies the data on tax paid to the government was available and for other companies five per cent of gross revenue from PPR vaccine sale was considered as sales tax and 12.36% of the licensing and royalty fee was considered as a service tax. The GTR was calculated at current prices and at 2017–18 constant prices using the wholesale price index. The GTR generated to various stakeholders viz., vaccine innovating institutions, vaccine producing and selling private companies/ public veterinary biological institutions and tax accrual to government was calculated as below,

1. Gross revenue of private vaccine producing company

$R_{\text{(}private)}\text{=}{\displaystyle \sum _{i\text{=1}}^n[(Q_1\ast P_1)+(Q_2\ast P_2)]}$

Where, R_(Private) is gross revenue generated from private biological (USD); Q₁ is the quantity/dose of PPR vaccine sold in domestic (No.); Q₂ is the quantity/dose of vaccine exported (No.); P₁ and P₂ are the corresponding prices of vaccine/dose (USD); n is a number of companies (private biological).

2. Gross revenue of public (government) biologicals

$R_{\text{(}public\text{)}}\text{=}{\displaystyle \sum _{j=1}^k\text{[(}{Q}_1\ast P_1\text{)+(}{Q}_2\ast P_2\text{)]}}$

Where, R_(public) is gross revenue from government/public biological (USD); Q₁ is the quantity/dose of vaccine sold in own state (No.); Q₂ is the quantity/dose of vaccine sold to other states (No.); P₁ and P₂ are the corresponding prices of vaccine/dose (USD); k is the number of government/public biologicals.

3. Gross revenue of vaccine innovating institution [ICAR-IVRI and TANUVAS)]

$R_{\text{(}devlp)}\text{=}{\displaystyle \sum _{i\text{=1}}^N\text{(}l+r\text{)}}$

and royalty fee is given by,

r = (R) * 0.03

Where, R_(devlp) is gross revenue generated by the developer (ICAR-IVRI and TANUVAS) (USD); l is a licensing fee paid for the procurement of vaccine (USD); r is a royalty fee paid by the producers (only from private companies) (USD); R is gross revenue generated by the company (R_private) (USD); N is the number of both companies/private and government/public biologicals.

4. Government revenue

$R_{\text{(}govt)}\text{=}{\displaystyle \sum _{i\text{=1}}^N\text{(}{T}_{sr}+T_{sl}\text{)}}$

and services tax and sales tax is given by,

T_sr = 0.1236 * (l + r)

T_sl = (R) * 0.05

Where, R_govt is gross revenue generated by the government due to PPR vaccine sales (USD); T_sr is service tax paid by the producer (USD); T_sl is sales tax paid by the producer (USD); l is a licensing fee paid for the PPR vaccine innovating institution (USD); r is a royalty fee paid by the producer (only from companies) (USD); R is gross revenue generated either by the company (R_private) or government (R_public) (USD); N is the number of both companies/private and government/public biologicals. All the costs were calculated in Indian rupees (INR) and converted to USD (USD=80 INR).

RESULTS

The data used for computing the R&D impact of PPR vaccine development in India were from secondary sources (Livestock Census Reports, published information in scientific journals, Annual reports, expert’s opinion) and primary survey undertaken in different states in India by the authors and the details are presented in Supplementary Table 1.

Incidence gap

The difference between projected incidence under without vaccination scenario and interpolated incidence under with vaccination in different years is presented in Fig. 1. The incidence gap between with and without vaccination narrows and tapers till 2025–26 inconsonance with increased vaccination coverage (Fig. 1). In India, PPR vaccination coverage was 5.88% during 2003–04 and later increased gradually and after PPR-CP implementation, the coverage increased considerably. In consonance with increased vaccination coverage, the PPR outbreaks gradually decreased indicating the inverse relationship between vaccination coverage and reported outbreaks (Fig. 2).

Fig. 2.

Represents Peste des Petits Ruminants (PPR) vaccination coverage and reported diagnosed cases during 1996–97 to 2019–20 in India.

Cash inflows, outflows and net benefits

The estimated cash outflows were USD 0.04 million/year (INR 0.32 crore) till the PPR vaccine development year (2001–02) and later outflows increased and reached USD 57.04 million (INR 456.32 crore) by 2023–24 due to increased vaccine coverage under PPR-CP in some of the southern states including Chhattisgarh state. Similarly, the cash inflows increased after 2004–05 and reached a maximum (USD 1,708.42 million (INR 13,667.3 crore) during 2025–26 under high incidence scenario followed by medium (USD 1,366.55 million (INR 10,932.40 crore)) and low incidence scenario (USD 1,138.64 million (INR 9,109.1 crore)). The net benefits were negative till 2003–04 and become positive in the later years till 2025–26. The cash inflows were substantial (USD 18,994.32 million (INR 151,954 crore)) under high incidence scenario as the expected benefits was higher in this scenario. The details are presented in Supplementary Table 2.

Financial indicators

Under low incidence scenario (10%), the estimated BCR, NPV and IRR was 43.3:1; USD 16,326.6 million (INR 130,612 crore) and 162.2% whereas under medium (12%) and high incidence scenario (15%) it was 48.8:1; USD 18,454.2 million (INR 147,633 crore); 167.6% and 57.1:1; USD 21,645.6 million (INR 130,612 crore) and 169.7%, respectively for the assessment period 1996–97 to 2025–26 (Table 1).

Table 1. Financial indicators of Peste des Petits Ruminants (PPR) vaccine development and administration to control PPR under actual (1996–97 to 2020–21) and planned future vaccination strategy (100% vaccination for three years [from 2021–22 to 2023–24) and 10% need based/ minimal vaccination coverage for two years (from 2024–25 to 2025–26)] in India.

Financial indicators	Disease incidence scenarios
	10%	12%	15%
Total programme cost (USD million)	386.0	386.0	386.0
Total benefits/ avoided loss (USD million)	16,712.6	18,840.2	22,031.6
Net benefits/ Net returns (NPV) (USD million)	16,326.6	18,454.2	21,645.6
IRR (%)	166.2	167.6	169.7
B:C ratio	43.3	48.8	57.1

All the estimates were calculated at 2020-21 prices at 5% discount rate.

GTR generated to different stakeholders

The GTR generated to different stakeholders is presented in Supplementary Table 3. The major direct beneficiary of PPR vaccine development was the public state biologicals (USD 7.141 million (INR 57.128 crore) followed by the private vaccine producing companies (USD 5 million (INR 40 crore)), vaccine innovating institutions viz., IVRI (USD 0.696 million (INR 5.56 crore)) and TANUVAS (USD 0.033 million (INR 0.264 crore)) and the government (USD 0.671 million (INR 5.368 crore)). The major revenue generated by PPR vaccine innovator (ICAR-IVRI) was through sale of vaccine USD 0.292 million (INR 2.336 crore) (42.0%), license fee USD 0.255 million (INR 2.04 crore) (36.6%) and royalty fee USD 0.148 million (INR 1.184 crore) (21.4%) and TANUVAS was through sale of vaccine USD 0.033 million (INR 0.264 crore). The government revenue was USD 0.621 million (INR 4.968 crore) (92.5%) through sales tax and USD 0.05 million (INR 0.40 crore) (7.5%) through service tax.

DISCUSSION

The present study considered varying PPR incidence and actual vaccination levels, as the PPR-CP was implemented only in southern states since 2010–11 and rest of the states adopted only focused vaccination with minimal coverage; considered the research cost in programme perspective (all the R&D institutes associated in PPR vaccine development); included the sero-monitoring and surveillance cost associated with the PPR control; and considered all the major farm-level disease avoidance benefits viz., decreased mortality, treatment cost, opportunity cost of labor, distress sale loss, milk and wool loss, reproduction loss and other costs. Further, the GTR accrued to various stakeholders associated with vaccine development and production was also assessed to understand the comprehensive impact of PPR vaccine development and administration in India.

The BCR estimates from a study [7] reported 122.92 at 7.5% discount rate whereas, the present study reported 43.3, 48.8 and 57.1 BCR under low, medium and high disease incidence scenarios, respectively. The BCR estimates is nine times higher than the earlier estimate (BCR 4.9) in Chhattisgarh sate, India [12]. This BCR variation was due to long-time consideration (vaccine development year (1996–97) to control year (2025–26)); country level assessment; using actual vaccination coverage data and all possible farm-level loss associated with PPR. The global study [14] estimated 33.8 BCR under most likely scenario for the proposed programme of global eradication of PPR and it corroborates with the present study estimates. A study on economic impact of rinderpest control (Pan-African Rinderpest Campaign (PARC)) programme in ten countries of sub-Saharan Africa estimated BCRs between 1.06 and 3.84 [9, 25, 26]. The benefits of PPR vaccination for a five-year period using a dynamic herd model estimated BCR of 12 [24]. Further, the BCR assessment [4] in northern Cameroon for PPR vaccination and helminth control ranged from 2.26 to 3.27 in goats and 3.01 to 4.23 in sheep over a five-year period.

The estimated NPV in the present study showed higher under the planned future vaccination strategy. If this strategy is adopted every year, the vaccination cost increases however the estimated benefits also increases considerably, as disease incidence decreases with increased vaccination coverage. The estimated NPV of Trypanosomosis vaccine research was USD 288 million using Economic Surplus approach [16]. The estimated IRR for the proposed programme of global eradication of PPR [14] range from 104% to 219% under low and high mortality scenarios and corroborates with the present study estimates ranging from 166.2% to 169.7% with a very conservative disease incidence levels (10%, 12% and 15%) in India.

There is variation in the financial viability estimates derived from different studies in different countries as some studies exclusively evaluated the vaccination intervention methods and some are ex-ante assessment with implausible assumptions. However, the R&D impact studies are essential to rationalize the research expenditure between and various activities with-in the sector. It also provides direction to the researchers on the area of research that benefits the resource poor farmers. Despite the comprehensive research cost consideration for developing the three PPR vaccines in the financial assessment, the present estimated benefits of R&D investment outweighed the cost in many folds. Further, besides monetary advantageous, the vaccine is socially acceptable in India. The vaccine development and its administration not only benefitted the sheep and goats rearing farmers through disease reduction but also benefited the vaccine innovator through the sale of technology know-how (vaccine) to the private vaccine producing company or the state veterinary biologicals in terms of license fee and royalty fee. Further, the government also earned revenue through taxes. PPR vaccine innovating institution in India does not have facilities for upscaling the production and marketing and hence transferred to the private and public veterinary biologicals.

The public biologicals had production facilities and supplies vaccines to the government veterinary dispensaries/ hospitals located in districts/ blocks/ villages. Similarly, the private manufacturers provide vaccines to the state governments where veterinary biologicals are not available as well as supply to the private dealers/shops that deal with veterinary products including vaccine. The public and private institutional linkages ensured the PPR vaccine availability throughout the country and increased the PPR vaccine access by the resource-poor sheep and goat rearing farmers in rural India. The PPR vaccine cost in India (USD 2.57/100 dose) is comparatively cheaper and affordable than the average cost in other countries (USD 10.0/100 dose) [14]. However, the vaccine delivery cost is ten times higher (USD 26/100 dose) than the vaccine cost due to extensive geographical spread of sheep and goat rearing production systems, limited veterinary infrastructure in some areas and hence combined vaccine development for multiple diseases will reduce the disease control cost significantly. Nevertheless, this study has few limitations such as only the major cost components of PPR at farm-level were considered, whereas the sectoral and inter-sectoral impact and export and import costs and benefits of PPR control were not considered in the study.

In conclusion, vaccines are environment-friendly, socially acceptable and economically viable than other measures of disease prevention and control. The high returns to research investment in PPR vaccine development in India implies the importance and need for potent vaccine against various other livestock diseases. The financial benefits of PPR vaccine development outweighed cost in manifolds and benefited vaccine innovator, vaccine producer and government besides other spin-off and spill-over effects. Though the cost of vaccine is less, the cost associated with field delivery and administration is high in India, hence it is necessary to develop combined vaccines to control multiple diseases at least cost. Further, preferential funding and big investment push are needed for vaccine development and administration to augment multiple and long-term benefits to various stakeholders. Furthermore, a large country like India with >220 million sheep and goat population, if planned to eradicate PPR, indigenous vaccine development is essential as the vaccines will be available as and when required in the control and eradication phases of PPR. This vaccine may also be provided to countries in India’s neighborhood and beyond for the successful control and eradication of this transboundary disease.

CONFLICT OF INTEREST

The authors declare that there are no conflicts of interest.