Intradermal rabies post-exposure prophylaxis can be abridged with no measurable impact on clinical outcome in Cambodia, 2003-2014

Puppies as the primary causal animal for human rabies cases: three-year prospective study of human rabies in the Philippines

Introduction

While rabies remains a global concern, detailed studies on human rabies, particularly regarding causal animals and the reasons for not receiving postexposure prophylaxis (PEP), are lacking.

Methods

We conducted a 3-year prospective study (October 2019-September 2022) at the Philippines' largest rabies referral center. We interviewed patients with suspected rabies and their families. We used LN34 qRT-PCR and rapid fluorescent focus inhibition test on saliva samples. We also compared our findings with two retrospective studies at the same hospital.

Results

We enrolled 151 patients, including 131 with potential rabies exposure. Similar to retrospective studies, the participants were predominantly males (75.5%), adults (76.8%), low-income individuals (91.4%), and rural dwellers (62.3%). The causal animals were mainly dogs (97.0%), with similar incubation periods, clinical symptoms, and a high proportion not receiving vaccines or immunoglobulins (93.2%). Most causal animals were owned by either the patients' households or their neighbors (60.2%), with a significant proportion being puppies (58.8%). Most patients had knowledge of rabies; however, reasons for not seeking PEP included misconceptions about minor bites not causing rabies (51.3%), beliefs in traditional healers (33.9%), and economic constraints (22.6%). Despite completing the WHO regimen, two PEP failures were observed. LN34 qRT-PCR detected 98 positive cases (sensitivity, 64.9%; 95% CI 56.7-72.5). These strains belong to the Southeast Asia 4 subclade.

Discussion

In conclusion, this study highlights the role of puppies as primary causal animals and the presence of misconceptions that preclude patients from acquiring PEP.

Update on laboratory data of animal rabies at the Centre Pasteur of Cameroon from 2014 to 2021

Rabies is a worldwide zoonotic disease mainly transmitted to humans by an infected dog bite. Despite the endemicity of rabies in dogs and few documented cases in Cameroon, there is still not enough data on frequency of rabies cases in animals. The present study aims to update data on the circulation of rabies in animals screened at the Centre Pasteur of Cameroon (CPC) between 2014 and 2021. The detection of rabies in animals was based on passive surveillance. Animal rabies cases were confirmed on brain biopsies using fluorescent antibody test and SYBR green based real-time RT-PCR for negative results confirmation. The total nucleoprotein (N) gene of animal-derived RABV isolated were amplified by hemi nested RT-PCR and subjected to phylogenetic analyses. From 2014 to 2021, a total of 92 animals including 86 dogs (93.5%), 3 cats, 2 pigs and 1 chiropteran were screened for rabies at the CPC. From the 86 dog sampled, 62.3% (54/86) were tested positive for rabies and 1 out of 3 cat samples was also tested positive. The PEP demand was very high (59,371) during the study period. Phylogenetic analyses assigned all 15 studied isolates successfully sequenced to the Africa-1a lineage belonging to the Cosmopolitan clade. The study highlights the frequent circulation of rabies in Cameroon and the role of dogs and cat as main reservoir and vector of rabies.

Human rabies despite post-exposure prophylaxis: a systematic review of fatal breakthrough infections after zoonotic exposures

Post-exposure prophylaxis (PEP) for rabies is widely administered and highly effective. Nevertheless, sporadic breakthrough infections (ie, rabies in people who have started PEP) have been reported. We conducted a systematic review of articles published between Jan 1, 1980 and June 1, 2022 to characterise breakthrough infections. After reviewing 3380 articles from across all continents, we identified 52 articles, which included a total of 122 breakthrough infections. We classified breakthrough infections on the basis of adherence to core practices (ie, wound cleaning and vaccine administration). Of 86 breakthrough infections with data, median time from exposure to symptom onset was 20 days (IQR 16-24). Most (89 [77%] of 115) participants received PEP within 2 days of an exposure. Severe wounds (defined as those involving multiple wound sites or bites to the head, face, or neck) were common (80 [69%] of 116 [with data]). Deviations from core practices were reported in 68 (56%) of 122 cases. Other possible causes for breakthrough infections included errors in the administration of rabies immunoglobulin, delays in seeking health care, and comorbidities or immunosuppression. Cold-chain integrity assessments and potency testing of PEP biologics were only rarely assessed (8 [7%] of 122 cases), neither of which were found to be a cause of breakthrough infections. Timely and appropriate administration of PEP is crucial to prevent rabies, and although people with high-risk exposures or immunosuppression can develop rabies despite adherence to core practices, this occurrence remains exceedingly rare.

Clinical, epidemiological, and spatial features of human rabies cases in Metro Manila, the Philippines from 2006 to 2015

Rabies remains a public health problem in the Philippines despite the widespread provision of rabies vaccines and rabies immunoglobulin (RIG) as post-exposure prophylaxis (PEP). Detailed descriptions of recent human rabies cases in the Philippines are scarce. This study aimed to describe the clinical, epidemiological, and spatial features of human rabies cases between January 1, 2006, and December 31, 2015. We conducted a retrospective hospital-based case record review of all patients admitted to one referral hospital in Manila who received a clinical diagnosis of rabies. During the 10-year study period there were 575 patients (average 57.5 cases per year, range 57 to 119) with a final diagnosis of rabies. Most patients were male (n = 404, 70.3%) and aged ≥ 20 years (n = 433, 75.3%). Patients mostly came from the National Capital Region (n = 160, 28.0%) and the adjacent Regions III (n = 197, 34.4%) and IV-A (n = 168, 29.4%). Case mapping and heatmaps showed that human rabies cases were continuously observed in similar areas throughout the study period. Most patients had hydrophobia (n = 444, 95.5%) and/or aerophobia (n = 432, 93.3%). The leading causative animals were dogs (n = 421, 96.3%) and cats (n = 16, 3.7%). Among 437 patients with animal exposure history, only 42 (9.6%) had been administered at least one rabies vaccine. Two patients (0.5%), young children bitten on their face, had received and a full course of rabies vaccine. Human rabies patients were continuously admitted to the hospital, with no notable decline over the study period. The geographical area in which human rabies cases commonly occurred also did not change. Few patients received PEP and there were two suspected cases of PEP failure. The retrospective design of this study was a limitation; thus, prospective studies are required.

Rabies remains a public health problem in the Philippines despite improvements in the availability of rabies vaccines and rabies immunoglobulin (RIG) as post-exposure prophylaxis (PEP). The incidence of rabies is highest in Metro Manila and surrounding areas. We reviewed the records of all human rabies patients admitted to the national infectious disease hospital in Manila between 2006 and 2015. This hospital treats most cases in this area. During the 10-year study period, human rabies cases were continuously admitted to the hospital, with no notable decline in numbers by year. Most patients were adult men bitten by domestic dogs. The geographical areas in which cases commonly occurred during the 10-year period also did not change over time. Only 9.6% of patients had received at least one dose of a rabies vaccine as PEP. Although the risk of PEP failure is reported to be almost zero, we identified two suspected cases of PEP failure. The retrospective design of this study was a limitation, and the exact details of PEP were not reliably available. As human rabies death is a significant public health concern, the circumstances of each case should be prospectively investigated. Further research is required to understand how to reduce the number of rabies cases.

Accessibility to rabies centers and human rabies post-exposure prophylaxis rates in Cambodia: A Bayesian spatio-temporal analysis to identify optimal locations for future centers

Rabies is endemic in Cambodia. For exposed humans, post-exposure prophylaxis (PEP) is very effective in preventing this otherwise fatal disease. The Institut Pasteur du Cambodge (IPC) in Phnom Penh was the primary distributor of PEP in Cambodia until 2018. Since then, and to increase distribution of PEP, two new centers have been opened by IPC in the provinces of Battambang and Kampong Cham. Data on bitten patients, who sometimes bring the head of the biting animal for rabies analyses, have been recorded by IPC since 2000. However, human cases are not routinely recorded in Cambodia, making it difficult to establish a human burden of disease and generate a risk map of dog bites to inform the selection of future PEP center locations in high-risk areas. Our aim was to assess the impact of accessibility to rabies centers on the yearly rate of PEP patients in the population and generate a risk map to identify the locations where new centers would be the most beneficial to the Cambodian population. To accomplish this, we used spatio-temporal Bayesian regression models with the number of PEP patients as the outcome. The primary exposure variable considered was travel time to the nearest IPC center. Secondary exposure variables consisted of travel time to a provincial capital and urban proportion of the population. Between 2000 and 2016, a total of 293,955 PEP patient records were identified. Our results showed a significant negative association between travel time to IPC and the rate of PEP patients: an increase in one hour travel time from the living location to IPC PEP centers leads to a reduction in PEP rate of 70% to 80%. Five provinces were identified as the most efficient locations for future centers to maximize PEP accessibility: Banteay Meanchey, Siem Reap, Takeo, Kampot and Svay Rieng. Adding a PEP center in every provincial capital would increase the proportion of Cambodians living within 60 minutes of a PEP center from 26.6% to 64.9%, and living within 120 minutes from 52.8% to 93.3%, which could save hundreds of lives annually.

Rabies is a fatal viral disease that affects the nervous system. It is endemic in many countries in Africa and Asia where free roaming dogs form a reservoir. Transmission to humans occurs most often through a dog bite. However, post-exposure prophylaxis (PEP), if administered before symptom onset, is highly effective at preventing the disease. In Cambodia, a few number of centers offer PEP, with the Institut Pasteur du Cambodge in Phnom Penh being the main one. These few locations lead to limited accessibility for rural areas distant from Phnom Penh and underestimations of the dog-bite burden and PEP needs. Through statistical modelling, we measured the impact of accessibility on the number of PEP patients and predicted the impact of opening new centers in other locations. We found that travel time was significantly associated with the rate of PEP patients. IPC opened new rabies centers in Battambang and Kampong Cham provinces in 2018 and 2019, respectively, and we identified four provinces where future openings would be the most beneficial: Banteay Meanchey, Siem Reap, Takeo, Kampot and Svay Rieng. This study is part of a broader drive to eradicate rabies in Cambodia by 2030 through increased PEP infrastructure and control measures in the dog population.

Safety and Immunogenicity of a novel three-dose recombinant nanoparticle rabies G protein vaccine administered as simulated post exposure immunization: A randomized, comparator controlled, multicenter, phase III clinical study

BACKGROUND

Rabies vaccines are lifesaving in human post animal exposure. However, the compliance to the complete course of vaccine is found to be only 60%. Hence, there is a need for safe and immunogenic, shorter course vaccine that can enhance the compliance and effectively prevent the disease.

OBJECTIVES

To establish a noninferiority of a novel three-dose recombinant rabies G protein vaccine to be administered as simulated postexposure prophylaxis when compared to five-dose WHO prequalified vaccine for better safety and immunogenicity.

METHODS

A multi-centric, open label, assessor blind, center-specific block randomized, parallel design, phase III clinical study was conducted among 800 subjects. The eligible subjects were randomized in 2:1 ratio for recombinant rabies G protein vaccine and the reference vaccine. Subjects in recombinant rabies G protein vaccine arm received three doses of vaccine on days 0, 3, and 7, while subjects in reference vaccine arm received five doses of WHO prequalified vaccine on days 0, 3, 7, 14, and 28.

RESULTS

The socio-demographic characteristics of the two arms were comparable. About 9.9% subjects in recombinant rabies G protein vaccine arm and 17.2% subjects in reference arm reported adverse events. The sero-protection on day 14 was found to be 99.24% and 97.72% in recombinant rabies G protein vaccine arm and reference vaccine arm respectively and the difference was statistically nonsignificant.

CONCLUSION

The novel three-dose recombinant rabies G protein vaccine administered as simulated postexposure prophylaxis was noninferior to five dose WHO prequalified vaccine in terms of safety and immunogenicity.

Human rabies: prospects for elimination

Almost half of all countries in the world are effectively free of human deaths from dog-mediated rabies. But the disease still affects people in low- and middle-income countries, especially the rural poor, and children. Successful regional elimination of human rabies is attributable to advances in significant and sustained investment in dog vaccination, post-exposure vaccination and surveillance, illustrated by productive efforts to reduce human rabies in Latin America over the last 35 years. Nonetheless, countries still facing endemic rabies face significant barriers to elimination. Using the 2017 Global Strategic Plan to end human rabies deaths from dog-mediated rabies by 2030 as a reference point and an organizing framework, we assess progress toward global rabies elimination by examining the characteristics of successful regional control efforts and barriers to elimination. Although substantive barriers exist for countries where rabies remains endemic, advances in knowledge, technology, institutions, and economics provide a basis for optimism.

A shorter post-exposure prophylaxis regimen for rabies, Pakistan

OBJECTIVE

To assess the cost and effectiveness of the two-site, 1-week, intradermal rabies post-exposure prophylaxis regimen recommended by the World Health Organization (WHO) in 2018.

METHODS

We compared the number of rabies vaccine and rabies immunoglobulin ampoules consumed at The Indus Hospital in Karachi, Pakistan and their cost before and after implementing WHO's 2018 recommendations. In 2017, patients with suspected rabies-infected bites were treated using the two-site, 4-week, Thai Red Cross regimen, which involved administering four rabies vaccine doses intradermally over 4 weeks and infiltrating immunoglobulin into serious wounds, with the remainder injected into a distant muscle. In 2018, patients received three vaccine doses intradermally over 1 week, with a calculated amount of immunoglobulin infiltrated into wounds only. Remaining immunoglobulin was saved for other patients. The survival of patients bitten by apparently rabid dogs was used as a surrogate for effectiveness.

FINDINGS

Despite treating 8.5% more patients in 2018 (5370 patients) than 2017 (4948 patients), 140 fewer ampoules of rabies vaccine and 436 fewer ampoules of rabies immunoglobulin were used, at a cost saving of 4202 United States dollars. Of 56 patients bitten by apparently rabid dogs, 50 were alive at 6-month follow-up. The remaining six patients could not be contacted but did not present to any hospital with rabies.

CONCLUSION

The new regimen was more economical than the two-site, 4-week regimen and was equally effective. This regimen is recommended for preventing rabies in countries where the disease is endemic and rabies vaccine and immunoglobulin are in short supply.

How geographic access to care shapes disease burden: The current impact of post-exposure prophylaxis and potential for expanded access to prevent human rabies deaths in Madagascar

Background

Post-exposure prophylaxis (PEP) is highly effective at preventing human rabies deaths, however access to PEP is limited in many rabies endemic countries. The 2018 decision by Gavi to add human rabies vaccine to its investment portfolio should expand PEP availability and reduce rabies deaths. We explore how geographic access to PEP impacts the rabies burden in Madagascar and the potential benefits of improved provisioning.

Methodology & principal findings

We use spatially resolved data on numbers of bite patients seeking PEP across Madagascar and estimates of travel times to the closest clinic providing PEP (N = 31) in a Bayesian regression framework to estimate how geographic access predicts reported bite incidence. We find that travel times strongly predict reported bite incidence across the country. Using resulting estimates in an adapted decision tree, we extrapolate rabies deaths and reporting and find that geographic access to PEP shapes burden sub-nationally. We estimate 960 human rabies deaths annually (95% Prediction Intervals (PI): 790–1120), with PEP averting an additional 800 deaths (95% PI: 640–970) each year. Under these assumptions, we find that expanding PEP to one clinic per district (83 additional clinics) could reduce deaths by 19%, but even with all major primary clinics provisioning PEP (1733 additional clinics), we still expect substantial rabies mortality. Our quantitative estimates are most sensitive to assumptions of underlying rabies exposure incidence, but qualitative patterns of the impacts of travel times and expanded PEP access are robust.

Conclusions & significance

PEP is effective at preventing rabies deaths, and in the absence of strong surveillance, targeting underserved populations may be the most equitable way to provision PEP. Given the potential for countries to use Gavi funding to expand access to PEP in the coming years, this framework could be used as a first step to guide expansion and improve targeting of interventions in similar endemic settings where PEP access is geographically restricted and baseline data on rabies risk is lacking. While better PEP access should save many lives, improved outreach, surveillance, and dog vaccination will be necessary, and if rolled out with Gavi investment, could catalyze progress towards achieving zero rabies deaths.

Canine rabies causes an estimated 60,000 deaths each year across the world, primarily in low- and middle-income countries where people have limited access to both human vaccines (post-exposure prophylaxis or PEP) and dog rabies vaccines. Given that we have the tools to prevent rabies deaths, a global target has been set to eliminate deaths due to canine rabies by 2030, and recently, Gavi, a multilateral organization that aims to improve access to vaccines in the poorest countries, added human rabies vaccine to it’s portfolio. In this study, we estimated reported incidence of patients seeking PEP in relation to travel times to clinics provisioning PEP and extrapolate human rabies deaths in Madagascar. We find that PEP currently averts around 800 deaths each year, but that the burden remains high (1000 deaths/year), particularly in remote, hard-to-reach areas. We show that expanding PEP availability to more clinics could significantly reduce rabies deaths in Madagascar, but our results reaffirm that expansion alone is will not achieve the global goal of zero human deaths from dog-mediated rabies by 2030. Combining PEP expansion with outreach, surveillance, and mass dog vaccination programs will be necessary to move Madagascar, and other Low- and Middle-Income countries, forward on the path to rabies elimination.

[New aspects of rabies control]

Rabies still causes about 60,000 human deaths per year, mainly in poor populations in Africa and Asia. However, since Louis Pasteur developed the first vaccine 130 years ago, prophylactic measures have been considerably improved and simplified. They now consist of the vaccine combined with purified rabies immunoglobulins of equine or human origin. In general, however, post-exposure prophylaxis protocols are long and expensive. Furthermore, the immunoglobulins used for associated serotherapy are costly and not widely available in developing countries. Approaches have been developed to deal with these two issues that offer hope for a paradigm shift for the benefit of exposed populations. Finally, mass rabies vaccination in dogs, which are the most cost-effective measure for preventing rabies in humans, are difficult to implement and sometimes have moderate effectiveness. The identification and analysis of the epidemiological drivers conditioning the circulation of the virus in dog populations allow a better understanding of the key control points that need to be associated with these campaigns for a better efficacy.

RABIES IMMUNOGLOBULIN: Brief history and recent experiences in Côte d'Ivoire

BACKGROUND

Rabies is a fatal viral zoonosis mainly transmitted via dog bites. The estimated 59'000 annual deaths caused by the disease are preventable through correct and timely administration of post-exposure prophylaxis (PEP). PEP should be initiated as soon as possible after an exposure to a rabies suspected animal and consists of a course of active vaccinations and administration of rabies immunoglobulin (RIG) in case of severe exposure. However, RIG is not accessible in most rabies endemic countries and its impact on survival in combination with modern vaccines and its cost-effectiveness is unclear. We examined the effect of equine RIG (eRIG) in a field-trial in Côte d'Ivoire, a developing country with low but chronic rabies burden and persistent lack of RIG, similar to a majority of rabies endemic countries attempting elimination of the disease.

METHODS

Data from 3367 patients attending anti-rabies centers (Centres Anti-Rabiques, CARs) of the National Institute for Public Hygiene (Institut National d'Hygiène Publique, INHP) in the departments of Bouaké and San Pédro in Côte d'Ivoire was prospectively collected between April 2016 and March 2018. We identified 1594 patients at risk of rabies infection as eligible for RIG administration. Depending on local availability of eRIG and vaccination protocol applied, PEP consisted of active immunization only (non-eRIG group, n = 1145) or active and passive immunization (eRIG group, n = 449). Patients were followed-up by phone interviews at least 15 months after their exposure to assess for rabies suspected deaths.

RESULTS

Follow-up data was available for 641 patients in the non-eRIG group (56%) and 242 in the eRIG group (54%). Three suspected or possible rabies deaths occurred in each of the two groups, corresponding to a possible rabies mortality of 1.2% (95% CI 0.3-3.6%) in the eRIG group and 0.5% (95% CI 0.1-1.4%) in the non-eRIG group. The difference in proportions was small and not statistically significant (0.7%, p = 0.21). Deaths in both groups were associated with treatment delay after exposure and non-compliance to PEP protocol. No death occurred after correct and timely active immunization independent of eRIG administration.

CONCLUSION

The provision of eRIG did not lead to a measurable reduction of rabies burden in our study population. This underlines that improved access to active vaccines will be effective in reducing rabies deaths even if access to eRIG remains difficult in developing countries. A possible benefit of eRIG administration for severely exposed patients cannot be excluded based on these results.

Health economic assessment of a rabies pre-exposure prophylaxis program compared with post-exposure prophylaxis alone in high-risk age groups in the Philippines

OBJECTIVES

Once symptoms appear, rabies is almost always fatal and accounts for 200-300 deaths annually in the Philippines. Available rabies vaccines can be administered either in pre- exposure prophylaxis (PrEP) or post-exposure prophylaxis (PEP). After exposure, PrEP-immunized individuals require fewer doses of PEP and no rabies immunoglobulin.

METHODS

A static decision-tree model was developed to assess cost-effectiveness of a PrEP+PEP program vs PEP alone. Philippines-specific data for people seeking medical advice at the Research Institute for Tropical Medicine between July 2015 and June 2016 were used in the model, together with data from published literature.

RESULTS

Over a 20-year period, in a cohort of 1 million 5-year-old children in the Philippines, PrEP+PEP was expected to prevent 297 deaths compared with PEP alone. From both payer and societal perspectives, the resulting incremental cost-effectiveness ratios were 36 035 (US$759; 2016 US$ conversion) and 18 663 (US$393) Philippine Pesos (PHP) - quality-adjusted life-years gained - respectively, which are both below the willingness-to-pay threshold of PHP140 255 (US$2 953).

CONCLUSION

These data suggest that a universal PrEP program targeting 5-year-olds would be cost-effective in the Philippines.

Modern biologics for rabies prophylaxis and the elimination of human cases mediated by dogs

Introduction: Rabies is a major viral zoonosis and neglected tropical disease, with a global distribution. Humans, domestic animals, and wild mammals are susceptible to infection. Etiological agents reside in the Order Mononegavirales, Family Rhabdoviridae, Genus Lyssavirus. This acute, progressive encephalitis causes the highest case fatality of any conventional infectious disease. Tens of millions of humans become exposed annually to the bites of infected mammals, predominantly in Asia and Africa. Despite the existence of effective vaccines and immune globulins, tens of thousands of people, typically children in the developing world, succumb. Areas covered: Concentrating upon both historical and major published references from the peer-reviewed literature over the past 5 years, we describe current biologics for rabies prevention, newly recommended principles for prophylaxis, and relevant future products in the developmental pipeline. Expert opinion: Modern human rabies biologics are pure, potent, safe, and efficacious, when used in a timely and appropriate manner. Few individuals survive after clinical signs. Anti-viral compounds are not licensed. Experimental therapy, while obviously desirable, is highly controversial. Education on bite prevention and integrated risk management are critical. Access to affordable care, dose-sparing, and shortened regimens of human rabies biologics remain key.

One Health in Practice: Using Integrated Bite Case Management to Increase Detection of Rabid Animals in Tanzania

Rabies is a neglected zoonotic disease that causes an estimated 59,000 human deaths worldwide annually, mostly in Africa and Asia. A target of zero human deaths from dog-mediated rabies has been set for 2030, and large-scale control programs are now advocated. However, in most low-income endemic countries surveillance to guide rabies control is weak and few cases of rabies are recorded. There is an urgent need to enhance surveillance to improve timely case detection and inform rabies control and prevention, by operationalizing a “One Health” approach. Here we present data from a study piloting Integrated Bite Case Management (IBCM) to support intersectoral collaboration between health and veterinary workers in Tanzania. We trained government staff to implement IBCM, comprising risk assessments of bite patients by health workers, investigations by livestock field officers to diagnose rabid animals, and use of a mobile phone application to support integration. IBCM was introduced across 20 districts in four regions of Tanzania and results reported after 1 year of implementation. Numbers of bite patient presentations to health facilities varied across regions, but following the introduction of IBCM reporting of bite patients at high-risk for rabies more than doubled in all regions. Over 800 high-risk investigations were carried out, with 49% assessed as probable dog rabies cases on the basis of clinical signs, animal outcome, and rapid diagnostic testing. The status of a further 20% of biting animals could not be determined but rabies could not be ruled out. Livestock field officers reported that use of rapid diagnostic tests (RDTs) were useful for confirming rabies occurrence. Overall, our study provides further evidence that IBCM is a practical approach that can improve rabies detection in endemic countries, and be used to monitor the impact of mass dog vaccinations, including potential to verify rabies freedom. However, the main challenges to implementation are limited training of health workers in rabies, perceived burden of real-time recording and limited resources for livestock field officers to undertake investigations. Nonetheless, IBCM dramatically improved case detection and communication between sectors and we recommend further implementation research to establish best practice and applicability to other settings.

A social justice perspective on access to human rabies vaccines

Rabies kills tens of thousands of people every year despite being entirely vaccine preventable. Key global health actors have launched a country-driven plan to achieve zero human deaths from dog-mediated rabies by 2030 worldwide. This partnership has recently been strengthened by Gavi, the Vaccine Alliance’s decision to invest in human rabies vaccines for post-exposure prophylaxis (PEP). While nation states are key to rabies elimination, the importance of Gavi’s role cannot be understated. Unlike any other actor, Gavi can directly address an otherwise intractable market failure in the inadequate supply of rabies PEP. In this commentary, we employ the Capabilities Approach to identify the barriers to PEP access that lead to this market failure and, as a result, unnecessary deaths and suffering. We show the role that Gavi can play in reducing exposure of PEP supply to market forces as a matter of social justice, and hence redress the inequity underlying human rabies deaths.

An evaluation of Brazil's surveillance and prophylaxis of canine rabies between 2008 and 2017

An effective surveillance system is critical for the elimination of canine rabies in Latin America. Brazil has made substantial progress towards canine rabies elimination, but outbreaks still occurred in the last decade in two states. Brazil uses a health information system (SINAN) to record patients seeking post-exposure prophylaxis (PEP) following contact with an animal suspected of having rabies. This study evaluated: (i) whether SINAN can be reliably used for rabies surveillance; (ii) if patients in Brazil are receiving appropriate PEP and (iii) the benefits of implementing the latest World Health Organization (WHO) recommendations on PEP. Analysing SINAN records from 2008 to 2017 reveals an average of 506,148 bite-injury patients/year [range: 437k-545k] in the country, equivalent to an incidence of 255 bite-injuries/100,000 people/year [range: 231–280]. The number of reports of bites from suspect rabid dogs generally increased over time. In most states, records from SINAN indicating a suspect rabid dog do not correlate with confirmed dog rabies cases reported to the Regional Information System for Epidemiological Surveillance of Rabies (SIRVERA) maintained by the Pan American Health Organization (PAHO). Analyses showed that in 2017, only 45% of patients received appropriate PEP as indicated by the Brazilian Ministry of Health guidance. Implementation of the latest WHO guidance using an abridged intradermal post-exposure vaccination regimen including one precautionary dose for dog bites prior to observation would reduce the volume of vaccine required by up to 64%, with potential for annual savings of over USD 6 million from reduced vaccine use. Our results highlight the need to improve the implementation of SINAN, including training of health workers responsible for delivering PEP using an Integrated Bite Case Management approach so that SINAN can serve as a reliable surveillance tool for canine rabies elimination.

Dog-mediated rabies has declined to only a few cases in Latin America over the last decade. Brazil has the largest human and dog population of Latin America. Despite the decline of canine rabies, the country’s public health system still spends millions of dollars annually on half a million patients seeking health care for dog bites. In this study, we analysed a decade of national surveillance data on dog bites. These data suggest that health workers report dog rabies in many states where the disease is likely to be absent, with false positive cases frequently reported into the surveillance system. In addition, only half of patients appear to receive the appropriate rabies post-exposure prophylaxis as recommended by the Ministry of Health. We estimated that Brazil could save up to USD 6 million per annum on vaccine by reducing the number of doses administered during prophylaxis and adopting the intradermal vaccine delivery technique following the latest WHO recommendations. Our study highlights an urgent need for updating health care workers on canine rabies knowledge, prophylaxis and assessment of dog bites to improve prophylaxis provision and surveillance of dog rabies.

Current status of human rabies prevention: remaining barriers to global biologics accessibility and disease elimination

Introduction: Rabies is a serious, neglected tropical disease. Zoonotic agents are RNA viruses (Genus Lyssavirus, Family Rhabdoviridae), global in distribution. As an acute, progressive, incurable encephalitis, rabies has the highest case fatality of any infectious disease. Warm-blooded vertebrates are susceptible hosts. Major mammalian reservoirs include mesocarnivores and bats. Given wildlife perpetuation, rabies is not eradicable, but is preventable and controllable, especially under newly available international guidelines. Areas covered: Literature review over the past 5 years reveals development of sensitive, specific diagnostic tests and safe and highly effective human and veterinary vaccines. Yet, tens of thousands of human fatalities occur annually, usually in Africa and Asia, primarily after canine exposure. Human and domestic animal vaccination, before or after exposure, is the single greatest preventative strategy following a rabid animal bite. Expert opinion: Significant progress occurred during the twenty-first century regarding vaccine development, doses, and schedules. Remaining barriers to widespread rabies vaccination include an inter-related set of economic, cultural, social, educational, ecological and technological factors. A basic understanding of local and regional root causes of cases historically allows for broader accessibility to vaccination in a trans-disciplinary fashion to meet the global elimination of human rabies caused via dogs (GEHRD) by 2030.

Cost Savings of Using Updated Thai Red Cross Intradermal Regimen in a High-Throughput Anti-Rabies Clinic in New Delhi, India

Replacement of the Essen intramuscular (EIM) by the updated Thai Red Cross intradermal (UTRCID) regimen for rabies post-exposure prophylaxis (PEP), in high-throughput hospitals of India, has been advocated since 2006 thanks to its cost-effectiveness. However, several anti-rabies clinics in India and other parts of the world have not initiated this switchover of regimens because of the paucity of financial literature, generated in realistic settings, regarding the same. We calculated the procurement costs of various items required for providing rabies vaccinations via the EIM regimen and UTRCID regimen, on an annual basis, a year before and after the switchover. From a healthcare provider’s perspective, the cost of vaccination per patient was calculated to be 5.60 USD for the EIM regimen and 2.40 USD for the UTRCID regimen. The switchover to the UTRCID regimen from the EIM regimen reduced the financial burden of the rabies vaccination by almost 60%. Procurement of vaccine vials contributed to the majority of the cost (>94%) in both of the regimens. Procurement of syringes with fixed needles contributed negligibly (<6%) to the financial burden in both the regimens. A policy to progressively switch over to the UTRCID regimen from the EIM in all high-throughput anti-rabies centers of India would dramatically reduce the economic burden of running a successful anti-rabies program.

Rabies post-exposure prophylaxis: A systematic review on abridged vaccination schedules and the effect of changing administration routes during a single course

Rabies is a fatal zoonotic disease preventable through timely and adequate post-exposure prophylaxis (PEP) to potentially exposed persons i.e. wound washing and antisepsis, a series of intradermal (ID) or intramuscular (IM) rabies vaccinations, and rabies immunoglobulin in WHO category III exposures. The 2010 WHO position on rabies vaccines recommended PEP schedules requiring up to 5 clinic visits over the course of approximately one month. Abridged schedules with less doses have potential to save costs, increase patient compliance, and thereby improve equitable access to life-saving PEP for at-risk populations. We systematically reviewed new evidence since that considered for the 2010 position paper to evaluate (i) the immunogenicity and effectiveness of PEP schedules of reduced dose and duration; (ii) new evidence on effective PEP protocols for special populations; and (iii) the effect of changing routes of administration (ID or IM) during a single course of PEP. Our search identified a total of 14 relevant studies. The identified studies supported a reduction in dose or duration of rabies PEP schedules. The 1-week, 2-site ID PEP schedule was found to be most advantageous, as it was safe, immunogenic, supported by clinical outcome data and involved the least direct costs (i.e. cost of vaccine) compared to other schedules. To supplement this evidence, as yet unpublished additional data were reviewed to support the strength of the recommendations. Evidence suggests that changes in the rabies vaccine product and/or the route of administration during PEP is possible. Few studies have evaluated PEP schedules in persons with suspect or confirmed rabies exposures. Gaps exist in understanding the safety and immunogenicity of novel PEP schedules in special populations such as infants and immunocompromised individuals. Available data indicate that administering rabies vaccines during pregnancy is safe and effective.

The potential effect of improved provision of rabies post-exposure prophylaxis in Gavi-eligible countries: a modelling study

BACKGROUND

Tens of thousands of people die from dog-mediated rabies annually. Deaths can be prevented through post-exposure prophylaxis for people who have been bitten, and the disease eliminated through dog vaccination. Current post-exposure prophylaxis use saves many lives, but availability remains poor in many rabies-endemic countries due to high costs, poor access, and supply.

METHODS

We developed epidemiological and economic models to investigate the effect of an investment in post-exposure prophylaxis by Gavi, the Vaccine Alliance. We modelled post-exposure prophylaxis use according to the status quo, with improved access using WHO-recommended intradermal vaccination, with and without rabies immunoglobulin, and with and without dog vaccination. We took the health provider perspective, including only direct costs.

FINDINGS

We predict more than 1 million deaths will occur in the 67 rabies-endemic countries considered from 2020 to 2035, under the status quo. Current post-exposure prophylaxis use prevents approximately 56 000 deaths annually. Expanded access to, and free provision of, post-exposure prophylaxis would prevent an additional 489 000 deaths between 2020 and 2035. Under this switch to efficient intradermal post-exposure prophylaxis regimens, total projected vaccine needs remain similar (about 73 million vials) yet 17·4 million more people are vaccinated, making this an extremely cost-effective method, with costs of US$635 per death averted and $33 per disability-adjusted life-years averted. Scaling up dog vaccination programmes could eliminate dog-mediated rabies over this time period; improved post-exposure prophylaxis access remains cost-effective under this scenario, especially in combination with patient risk assessments to reduce unnecessary post-exposure prophylaxis use.

INTERPRETATION

Investing in post-exposure vaccines would be an extremely cost-effective intervention that could substantially reduce disease burden and catalyse dog vaccination efforts to eliminate dog-mediated rabies.

FUNDING

World Health Organization.

Evaluating new rabies post-exposure prophylaxis (PEP) regimens or vaccines

The development of human rabies vaccines has evolved dramatically from the first crude nerve tissue vaccine produced then administered in the presence of Louis Pasteur in 1885. New cell culture technology has enabled highly potent and well-tolerated rabies vaccines to be produced that have reduced the volume and number of doses required to save human lives after exposure. However, these highly potent vaccines are still unaffordable to many patients living at risk of exposure on a daily basis. The cost of post-exposure prophylaxis (PEP) is not only related to the direct cost of rabies biologicals and equipment but is also associated with indirect costs that patients incur as a result of travel, loss of work time (income loss), and accommodation over the period of time that a PEP regimen requires to be completed. This paper summarizes the particular criteria that the SAGE Working Group and WHO personnel reviewed as part of the evaluation process for recommending the new one-week intradermal vaccination regimen (2-2-2-0-0) for rabies post-exposure prophylaxis. These criteria included: Cost-effectiveness; evaluation of number of doses; seroconversion after vaccination; efficacy; safety; and patient follow-up.