Nipah@20: Lessons Learned from Another Virus with Pandemic Potential

Recent Advances in Immunological Landscape and Immunotherapeutic Agent of Nipah Virus Infection

Over the last two decades, the Nipah virus (NiV) emerged as a highly lethal zoonotic pathogen to humans. Outbreaks occurred occasionally in South and Southeast Asia. Therefore, a safe and effective vaccine against the virus is needed to fight against the deadly virus. Understanding the immunological landscape during this lethal virus infection is necessary in this direction. However, we found scattered information on the immunological landscape of the virus's reservoir, as well as hosts such as humans and livestock. The review provides a recent understanding of the immunological landscape of the virus's reservoir, human hosts, monoclonal antibodies, and vaccines for NiV infection. To describe the immunological landscape, we divided our review article into some points. Firstly, we illustrated bats' immune response as a reservoir during the NiV infection. Secondly, we illustrated an overview of the molecular mechanisms underlying the immune response to the NiV infection, various immune cells, humans' innate immune response, adaptive immunity, and the landscape of cytokines and chemokines. We also discussed INF escape, NET evasion, the T cell landscape, and the B cell landscape during virus infection. Thirdly, we also demonstrated the potential monoclonal antibody therapeutics, and vaccines. Finally, neutralizing antibodies (nAbs) of NiV and potentially other therapeutic strategies were discussed. The review will help researchers for better understanding the immunological landscape, mAbs, and vaccines, enabling them to develop their next-generation versions.

Measures to prevent and treat Nipah virus disease: research priorities for 2024-29

Nipah virus causes highly lethal disease, with case-fatality rates ranging from 40% to 100% in recognised outbreaks. No treatments or licensed vaccines are currently available for the prevention and control of Nipah virus infection. In 2019, WHO published an advanced draft of a research and development roadmap for accelerating development of medical countermeasures, including diagnostics, therapeutics, and vaccines, to enable effective and timely emergency response to Nipah virus outbreaks. This Personal View provides an update to the WHO roadmap by defining current research priorities for development of Nipah virus medical countermeasures, based primarily on literature published in the last 5 years and consensus opinion of 15 subject matter experts with broad experience in development of medical countermeasures for Nipah virus or experience in the epidemiology, ecology, or public health control of outbreaks of Nipah virus. The research priorities are organised into four main sections: cross-cutting issues (for those that apply to more than one category of medical countermeasures), diagnostics, therapeutics, and vaccines. The strategic goals and milestones identified in each section focus on key achievements that are needed over the next 6 years to ensure that the necessary tools are available for rapid response to future outbreaks of Nipah virus or related henipaviruses.

Universal paramyxovirus vaccine design by stabilizing regions involved in structural transformation of the fusion protein

The Paramyxoviridae family encompasses medically significant RNA viruses, including human respiroviruses 1 and 3 (RV1, RV3), and zoonotic pathogens like Nipah virus (NiV). RV3, previously known as parainfluenza type 3, for which no vaccines or antivirals have been approved, causes respiratory tract infections in vulnerable populations. The RV3 fusion (F) protein is inherently metastable and will likely require prefusion (preF) stabilization for vaccine effectiveness. Here we used structure-based design to stabilize regions involved in structural transformation to generate a preF protein vaccine antigen with high expression and stability, and which, by stabilizing the coiled-coil stem region, does not require a heterologous trimerization domain. The preF candidate induces strong neutralizing antibody responses in both female naïve and pre-exposed mice and provides protection in a cotton rat challenge model (female). Despite the evolutionary distance of paramyxovirus F proteins, their structural transformation and local regions of instability are conserved, which allows successful transfer of stabilizing substitutions to the distant preF proteins of RV1 and NiV. This work presents a successful vaccine antigen design for RV3 and provides a toolbox for future paramyxovirus vaccine design and pandemic preparedness.

Animal Models for Henipavirus Research

Hendra virus (HeV) and Nipah virus (NiV) are zoonotic paramyxoviruses in the genus Henipavirus (HNV) that emerged nearly thirty years ago. Outbreaks of HeV and NiV have led to severe respiratory disease and encephalitis in humans and animals characterized by a high mortality rate. Despite the grave threat HNVs pose to public health and global biosecurity, no approved medical countermeasures for human use currently exist against HeV or NiV. To develop candidate vaccines and therapeutics and advance the field's understanding of HNV pathogenesis, animal models of HeV and NiV have been instrumental and remain indispensable. Various species, including rodents, ferrets, and nonhuman primates (NHPs), have been employed for HNV investigations. Among these, NHPs have demonstrated the closest resemblance to human HNV disease, although other animal models replicate some key disease features. Here, we provide a comprehensive review of the currently available animal models (mice, hamsters, guinea pigs, ferrets, cats, dogs, nonhuman primates, horses, and swine) to support HNV research. We also discuss the strengths and limitations of each model for conducting pathogenesis and transmission studies on HeV and NiV and for the evaluation of medical countermeasures.

Nipah Virus Bangladesh Infection Elicits Organ-Specific Innate and Inflammatory Responses in the Marmoset Model

The common marmoset (Callithrix jacchus) is increasingly recognized as an ideal nonhuman primate (NHP) at high biocontainment due to its smaller size and relative ease of handling. Here, we evaluated the susceptibility and pathogenesis of Nipah virus Bangladesh strain (NiVB) infection in marmosets at biosafety level 4. Infection via the intranasal and intratracheal route resulted in fatal disease in all 4 infected marmosets. Three developed pulmonary edema and hemorrhage as well as multifocal hemorrhagic lymphadenopathy, while 1 recapitulated neurologic clinical manifestations and cardiomyopathy on gross pathology. Organ-specific innate and inflammatory responses were characterized by RNA sequencing in 6 different tissues from infected and control marmosets. Notably, a unique transcriptome was revealed in the brainstem of the marmoset exhibiting neurological signs. Our results provide a more comprehensive understanding of NiV pathogenesis in an accessible and novel NHP model, closely reflecting clinical disease as observed in NiV patients.

Host–Pathogen Interactions Influencing Zoonotic Spillover Potential and Transmission in Humans

Emerging infectious diseases of zoonotic origin are an ever-increasing public health risk and economic burden. The factors that determine if and when an animal virus is able to spill over into the human population with sufficient success to achieve ongoing transmission in humans are complex and dynamic. We are currently unable to fully predict which pathogens may appear in humans, where and with what impact. In this review, we highlight current knowledge of the key host–pathogen interactions known to influence zoonotic spillover potential and transmission in humans, with a particular focus on two important human viruses of zoonotic origin, the Nipah virus and the Ebola virus. Namely, key factors determining spillover potential include cellular and tissue tropism, as well as the virulence and pathogenic characteristics of the pathogen and the capacity of the pathogen to adapt and evolve within a novel host environment. We also detail our emerging understanding of the importance of steric hindrance of host cell factors by viral proteins using a “flytrap”-type mechanism of protein amyloidogenesis that could be crucial in developing future antiviral therapies against emerging pathogens. Finally, we discuss strategies to prepare for and to reduce the frequency of zoonotic spillover occurrences in order to minimize the risk of new outbreaks.

Evaluation of three rapid low-resource molecular tests for Nipah virus

Accurate and timely diagnosis of Nipah virus (NiV) requires rapid, inexpensive, and robust diagnostic tests to control spread of disease. Current state of the art technologies are slow and require laboratory infrastructure that may not be available in all endemic settings. Here we report the development and comparison of three rapid NiV molecular diagnostic tests based on reverse transcription recombinase-based isothermal amplification coupled with lateral flow detection. These tests include a simple and fast one-step sample processing step that inactivates the BSL-4 pathogen, enabling safe testing without the need for multi-step RNA purification. The rapid NiV tests targeted the Nucleocapsid protein (N) gene with analytical sensitivity down to 1,000 copies/μL for synthetic NiV RNA and did not cross-react with RNA of other flaviviruses or Chikungunya virus, which can clinically present with similar febrile symptoms. Two tests detected 50,000-100,000 TCID₅₀/mL (100-200 RNA copies/reaction) of the two distinct strains of NiV, Bangladesh (NiV_B) and Malaysia (NiV_M), and took 30 min from sample to result, suggesting these tests are well suited for rapid diagnosis under resource-limited conditions due to rapidity, simplicity, and low equipment requirements. These Nipah tests represent a first step toward development of near-patient NiV diagnostics that are appropriately sensitive for first-line screening, sufficiently robust for a range of peripheral settings, with potential to be safely performed outside of biohazard containment facilities.

Genetic Diversity and Expanded Host Range of J Paramyxovirus Detected in Wild Small Mammals in China

J paramyxovirus (JPV) is a rodent-borne Jeilongvirus isolated from moribund mice (Mus musculus) with hemorrhagic lung lesions trapped in the 1972 in northern Queensland, Australia. The JPV antibodies have been detected in wild mice, wild rats, pigs, and human populations in Australia. Here, by next-generation sequencing (NGS), we detected JPV from M. musculus in Shandong Province of China. Molecular detection of JPV was performed to survey to survey the infection among 66 species of wild small mammals collected from six eco-climate regions in China by applying JPV specific RT-PCR and sequencing. Altogether, 21 out of 3070 (0.68%) wild small mammals of four species were positive for JPV, including 5.26% (1/19) of Microtus fortis, 3.76% (17/452) of M. musculus, 1.67% (1/60) of Apodemus peninsulae, and 0.48% (2/421) of Apodemus agrarius, which captured three eco-climate regions of China (northeastern China, northern China, and Inner Mongolia-Xinjiang). Sequence analysis revealed the currently identified JPV was clustered with other 14 Jeilongvirus members, and shared 80.2% and 89.2% identity with Australia's JPV partial RNA polymerase (L) and glycoprotein (G) genes, respectively. Phylogenetic analysis demonstrated the separation of three lineages of the current JPV sequences. Our results show three new hosts (A. agrarius, A. peninsulae, and M. fortis) for JPV, most of which were widely distributed in China, and highlight the potential zoonotic transmission of JPV in humans. The detection of JPV in wild small mammals in China broaden the viral diversity, geographical distribution, and reservoir types of JPV. Future studies should prioritize determining the epidemiological characteristics of JPV, so that potential risks can be mitigated.

Elicitation of immune responses against Nipah virus by an engineered synthetic DNA vaccine

Nipah virus (NiV) is a re-emerging pathogen that causes severe disease in animals and humans. Current treatment measures for NiV infection are insufficient, and there is no approved vaccine against NiV for either humans or animals. Nipah virus is listed as a high-priority pathogen for vaccine and therapeutic research by the World Health Organization (WHO). In the present study, we employed synthetic enhanced DNA technologies developed to design and produce novel consensus NiV Fusion (NiV-F) and Glycoprotein (NiV-G) antigen sequences for inclusion in synthetic DNA vaccines for NiV. The expression of each vaccine antigen was confirmed in vitro using immune-binding assays. Electroporation-enhanced intramuscular injection of each NiV-F and NiV-G into mice induced potent cellular immune responses to multiple epitopes of NiV-G and NiV-F that included antigen-specific CD8+ T cells. Both vaccines elicited high antibody titers in mice, with a single immunization sufficient to seroconvert 100% of immunized animals. Additionally, the NiV-F vaccine also induced antibodies to neutralize NiV-F-pseudotyped virus particles. These data support further study of these novel synthetic enhanced NiV nucleic acid-based antigens as potential components of an effective vaccine against the Nipah virus.

Knowledge, Attitudes, Risk Perception, Preparedness and Vaccine Intent of Health Care Providers towards the Nipah Virus in South India

Nipah virus (NiV) disease (NVD) remains a re-emerging public health threat in India. We assessed the knowledge, attitudes, and risk perception of NVD and future vaccine intent among a convenience sample of health care providers (HCP). The primary outcome measures were the knowledge, attitudes, and risk perception scores. Of 261 participants surveyed, 203 (77.8%) had heard of NiV and associated symptoms. The majority (248, 95%) identified the fruit bat as a primary NiV reservoir and 205 (79.8%) were aware of human-to-human transmission via droplets. Only 101 (38.7%) participants were aware that drinking date palm sap is a risk factor for transmission. Most HCP either agreed (117 (44.8%)) or strongly agreed (131 (50.2%)) that NiV is a serious illness. Less than half (121 (46.4%)) were aware of any institutional protocol for NiV; 235 (90.7%) of HCP stated that they need more information about prevention and treatment options. Knowledge scores were significantly higher among physicians compared to nurses whereas nurses and academic providers were more likely to have higher attitudes scores. A majority of respondents (20,779.9%) were willing to be vaccinated and willing to recommend the NiV vaccine to their patients (21,682.8%). Future strategies include education of HCP to bridge the knowledge gaps and enhance preparedness through disease-specific training for NiV infection.

Henipaviruses-A constant threat to livestock and humans

In this review, we highlight the risk to livestock and humans from infections with henipaviruses, which belong to the virus family Paramyxoviridae. We provide a comprehensive overview of documented outbreaks of Nipah and Hendra virus infections affecting livestock and humans and assess the burden on the economy and health systems. In an increasingly globalized and interconnected world, attention must be paid to emerging viruses and infectious diseases, as transmission routes can be rapid and worldwide.

Response of the health system in Nipah outbreak in Ernakulam district: A qualitative analysis

Background:

Nipah is an emerging zoonotic disease that is transmitted through contaminated food or directly between people. Recently, Nipah virus infection was confirmed in Kochi, Kerala, making it the fourth outbreak reported in India. However, due to its good epidemic response, the health system of Kerala was able to control it in a timely manner.

Objective:

To qualitatively analyse the response of the health system of Kerala in controlling the Nipah outbreak (2019) by identifying the enabling factors and the challenges faced by it.

Methods:

A qualitative study was conducted using grounded theory approach. Key informant interviews were conducted till data saturation was reached. The audio recorded data was translated, transcribed and was manually coded and thematically analysed.

Results:

The major enablers for its apt response were identified to be effective communication, good line of control, effective division of work, intersectorial coordination, strong leadership, political commitment, resilient public private partnership and support groups, past experiences in disaster management, quick procurement of medicines and availability of lab facilities. On the other hand, the challenges identified were initial confusions, lack of standard operating procedures/guidelines for epidemic management, complacency, lack of effective zoonotic surveillance, media management and community participation.

Conclusion:

This study attributes the success of the outbreak response to the strong leadership and political commitment. In order to prevent recurrences in the future, there is a need to build a resilient health system through capacity building and further strengthening of the surveillance system.

Cooperativity mediated by rationally selected combinations of human monoclonal antibodies targeting the henipavirus receptor binding protein

Hendra virus and Nipah virus (NiV), members of the Henipavirus (HNV) genus, are zoonotic paramyxoviruses known to cause severe disease across six mammalian orders, including humans. We isolated a panel of human monoclonal antibodies (mAbs) from the B cells of an individual with prior exposure to equine Hendra virus (HeV) vaccine, targeting distinct antigenic sites. The most potent class of cross-reactive antibodies achieves neutralization by blocking viral attachment to the host cell receptors ephrin-B2 and ephrin-B3, with a second class being enhanced by receptor binding. mAbs from both classes display synergistic activity in vitro. In a stringent hamster model of NiV Bangladesh (NiV_B) infection, antibodies from both classes reduce morbidity and mortality and achieve synergistic protection in combination. These candidate mAbs might be suitable for use in a cocktail therapeutic approach to achieve synergistic potency and reduce the risk of virus escape.

Doyle et al. describe two human monoclonal antibodies that target the henipavirus receptor-binding protein, HENV-103 and HENV-117, that display highly potent activity in vitro and enhanced therapeutic efficacy in vivo when delivered as a cocktail.

One Year on: An Overview of Singapore's Response to COVID-19-What We Did, How We Fared, How We Can Move Forward

Background—One year has passed since the first COVID-19 case in Singapore. This scoping review commemorates Singaporean researchers that have expanded the knowledge on this novel virus. We aim to provide an overview of healthcare-related articles published in peer-reviewed journals, authored by the Singapore research community about COVID-19 during the first year of the pandemic. Methods—This was reported using the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) protocol. It included healthcare-related articles about COVID-19 published between 23 January 2020 and 22 January 2021 with a Singapore-affiliated author. MEDLINE, Embase, Scopus, Web of Science, CINAHL, PsycINFO, Google Scholar, and local journals were searched. The articles were screened independently by two reviewers. Results—The review included 504 articles. Most of the articles narrated the changes to hospital practice (210), while articles on COVID-19 pathology (94) formed most of the non-narrative papers. Publications on public health (61) and the indirect impacts to clinical outcomes (45) were other major themes explored by the research community. The remaining articles detailed the psychological impact of the pandemic (35), adaptations of medical education (30), and narratives of events (14). Conclusion—Amidst a resurgence of community cases involving variant COVID-19 strains, the resources from the research community will provide valuable guidance to navigate these uncertain times.

Nipah virus: a potential pandemic agent in the context of the current severe acute respiratory syndrome coronavirus 2 pandemic

For centuries, zoonotic diseases have been responsible for various outbreaks resulting in the deaths of millions of people. The best example of this is the current coronavirus disease 2019 (COVID-19) pandemic. Like severe acute respiratory syndrome coronavirus, Nipah virus is another deadly virus which has caused several outbreaks in the last few years. Though it causes a low number of infections, disease severity results in a higher death rate. In the context of the recent COVID-19 pandemic, we speculate that many countries will be unable to deal with the sudden onset of such a viral outbreak. Thus, further research and attention to the virus are needed to address future outbreaks.

Neurologic Manifestations of the World Health Organization's List of Pandemic and Epidemic Diseases

The World Health Organization (WHO) monitors the spread of diseases globally and maintains a list of diseases with epidemic or pandemic potential. Currently listed diseases include Chikungunya, cholera, Crimean-Congo hemorrhagic fever, Ebola virus disease, Hendra virus infection, influenza, Lassa fever, Marburg virus disease, Neisseria meningitis, MERS-CoV, monkeypox, Nipah virus infection, novel coronavirus (COVID-19), plague, Rift Valley fever, SARS, smallpox, tularemia, yellow fever, and Zika virus disease. The associated pathogens are increasingly important on the global stage. The majority of these diseases have neurological manifestations. Those with less frequent neurological manifestations may also have important consequences. This is highlighted now in particular through the ongoing COVID-19 pandemic and reinforces that pathogens with the potential to spread rapidly and widely, in spite of concerted global efforts, may affect the nervous system. We searched the scientific literature, dating from 1934 to August 2020, to compile data on the cause, epidemiology, clinical presentation, neuroimaging features, and treatment of each of the diseases of epidemic or pandemic potential as viewed through a neurologist's lens. We included articles with an abstract or full text in English in this topical and scoping review. Diseases with epidemic and pandemic potential can be spread directly from human to human, animal to human, via mosquitoes or other insects, or via environmental contamination. Manifestations include central neurologic conditions (meningitis, encephalitis, intraparenchymal hemorrhage, seizures), peripheral and cranial nerve syndromes (sensory neuropathy, sensorineural hearing loss, ophthalmoplegia), post-infectious syndromes (acute inflammatory polyneuropathy), and congenital syndromes (fetal microcephaly), among others. Some diseases have not been well-characterized from a neurological standpoint, but all have at least scattered case reports of neurological features. Some of the diseases have curative treatments available while in other cases, supportive care remains the only management option. Regardless of the pathogen, prompt, and aggressive measures to control the spread of these agents are the most important factors in lowering the overall morbidity and mortality they can cause.