Wastewater-based surveillance (WBS) has shown to be an effective tool in monitoring the spread of SARS-CoV-2 and has helped guide public health actions. Consequently, WBS has expanded to now include the monitoring of mpox virus (MPXV) to contribute to its mitigation efforts. In this study, we demonstrate a unique sample processing and a molecular diagnostic strategy for MPXV detection that can inform on the epidemiological situation of mpox outbreaks through WBS. We conducted WBS for MPXV in 22 Canadian wastewater treatment plants (WWTPs) for 14 weeks. Three MPXV qPCR assays were assessed in this study for the detection of MPXV which include the G2R assays (G2R_WA and G2R_G) developed by the Centers for Disease Control and Prevention (CDC) in 2010, and an in-house-developed assay that we have termed G2R_NML. The G2R_NML assay was designed using reference genomes from the 2022 MPXV outbreak and provides a larger qPCR amplicon size to facilitate Sanger sequencing. Results show that all three assays have similar limits of detection and are able to detect the presence of MPXV in wastewater. The G2R_NML assay produced a significantly greater number of Sanger sequence-confirmed MPXV results compared to the CDC G2R assays. Detection of MPXV was possible where provincial surveillance indicated overall low caseloads, and in some sites forewarning of up to several weeks was observed. Overall, this study proposes that WBS of MPXV provides additional information to help fill knowledge gaps in clinical case-surveillance and is potentially an essential component to the management of mpox.
Although there are now approved treatments and vaccines for Ebola virus disease, the case fatality rate remains unacceptably high even when patients are treated with the newly approved therapeutics. Furthermore, these countermeasures are not expected to be effective against disease caused by other filoviruses. A meeting of subject-matter experts was held during the 10th International Filovirus Symposium to discuss strategies to address these gaps. Several investigational therapeutics, vaccine candidates, and combination strategies were presented. The greatest challenge was identified to be the implementation of well-designed clinical trials of safety and efficacy during filovirus disease outbreaks. Preparing for this will require agreed-upon common protocols for trials intended to bridge multiple outbreaks across all at-risk countries. A multinational research consortium including at-risk countries would be an ideal mechanism to negotiate agreement on protocol design and coordinate preparation. Discussion participants recommended a follow-up meeting be held in Africa to establish such a consortium.
The sudden emergence and spread of Monkeypox in non-endemic parts of the world is currently not well understood. Infections are often mis-diagnosed and surveillance strategies are scarce. Wastewater-based surveillance (WBS) of human Monkeypox virus (MPXV) can help supplement our current clinical surveillance and mitigation efforts. WBS has shown to be an effective tool in monitoring the spread of other infectious pathogens, such as SARS-CoV-2 and its variants, and has helped guide public health actions. In this study, we describe how WBS can be used to detect MPXV in wastewater. We conducted WBS for MPXV in 22 wastewater treatment plants (WWTPs) over a period of 14 weeks. Nucleic acids were extracted using the MagAttract PowerMicrobiome DNA/RNA extraction kit. Three real-time qPCR assays were assessed for the detection of MPXV in wastewater. These included the G2R assays (G2R\_WA and G2R\_G) developed by the Centers for Disease Control and Prevention (CDC) in 2010, as well as an in-house-developed assay (G2R\_NML). The G2R\_G (generic) assay was designed to detect both the Congo and West African clades (re-named to Clades one and two, respectively) of viruses while the G2R\_WA assay was designed to detect the West African clade (Clade one). The G2R\_NML assay was designed using reference genomes of the 2022 MPXV outbreak. Our results show that all three assays have similar limits of detection and are all able to detect the presence of MPXV in wastewater. Following detection through real time qPCR, Sanger sequencing was performed on the resulting amplicon products, with the assembled contigs then undergoing analysis using nucleotide Basic Local Alignment Search Tool (BLAST). Due in part to the longer amplicon size of the G2R_NML assay, a significantly greater number of positive detections were identified as originating from MPXV compared to the CDC G2R assays. The ability to detect trace amounts of MPXV in wastewater as well as obtain Sanger sequence confirmation, has allowed for the successful surveillance of this virus in wastewater.### Competing Interest StatementThe authors have declared no competing interest.### Funding StatementThis study was funded by internal funds (Government of Canada)### Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesI confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesAll data produced in the present study are available upon reasonable request to the authors
The world remains at risk of an influenza pandemic, and the development of new therapeutic and preventative modalities is critically important for minimizing human death and suffering during the next influenza pandemic. Animal models are central to the development of new therapies and vaccine approaches.
Enhanced virulence and/or transmission of West African Ebola virus (EBOV) variants, which are divergent from their Central African counterparts, are suspected to have contributed to the sizable toll of the recent Ebola virus disease (EVD) outbreak. This study evaluated the pathogenicity and shedding in rhesus macaques infected with 1 of 2 West African isolates (EBOV-C05 or EBOV-C07) or a Central African isolate (EBOV-K). All animals infected with EBOV-C05 or EBOV-C07 died of EVD, whereas 2 of 3 EBOV-K-infected animals died. The viremia level was elevated 10-fold in EBOV-C05-infected animals, compared with EBOV-C07- or EBOV-K-infected animals. More-severe lung pathology was observed in 2 of 6 EBOV-C05/C07-infected macaques. This is the first detailed analysis of the recently circulating EBOV-C05/C07 in direct comparison to EBOV-K with 6 animals per group, and it showed that EBOV-C05 but not EBOV-C07 can replicate at higher levels and cause more tissue damage in some animals. Increased virus shedding from individuals who are especially susceptible to EBOV replication is possibly one of the many challenges facing the community of healthcare and policy-making responders since the beginning of the outbreak.
Concern over Ebola becoming endemic in West Africa has appeared in the medical and lay media. Routes of transmission, rates of viral evolution, suitability of humans as hosts and rarity of spillover events make this very unlikely. Without evidence that endemic Ebola is likely, ending epidemics should remain the focus.
As the Ebola outbreak in West Africa continues and cases appear in the United States and other countries, the need for long-lasting vaccines to preserve global health is imminent. Here, we evaluate the long-term efficacy of a respiratory and sublingual (SL) adenovirus-based vaccine in non-human primates in two phases. In the first, a single respiratory dose of 1.4×10(9) infectious virus particles (ivp)/kg of Ad-CAGoptZGP induced strong Ebola glycoprotein (GP) specific CD8+ and CD4+ T cell responses and Ebola GP-specific antibodies in systemic and mucosal compartments and was partially (67%) protective from challenge 62 days after immunization. The same dose given by the SL route induced Ebola GP-specific CD8+ T cell responses similar to that of intramuscular (IM) injection, however, the Ebola GP-specific antibody response was low. All primates succumbed to infection. Three primates were then given the vaccine in a formulation that improved the immune response to Ebola in rodents. Three primates were immunized with 2.0×10(10) ivp/kg of vaccine by the SL route. Diverse populations of polyfunctional Ebola GP-specific CD4+ and CD8+ T cells and significant anti-Ebola GP antibodies were present in samples collected 150 days after respiratory immunization. The formulated vaccine was fully protective against challenge 21 weeks after immunization. While diverse populations of Ebola GP-specific CD4+ T cells were produced after SL immunization, antibodies were not neutralizing and the vaccine was unprotective. To our knowledge, this is the first time that durable protection from a single dose respiratory adenovirus-based Ebola vaccine has been demonstrated in primates.
ZMAb is a promising treatment against Ebola virus (EBOV) disease that has been shown to protect 50% (two of four) of nonhuman primates (NHPs) when administered 2 days post-infection (dpi). To extend the treatment window and improve protection, we combined ZMAb with adenovirus-vectored interferon-α (Ad-IFN) and evaluated efficacy in EBOV-infected NHPs. Seventy-five percent (three of four) and 100% (four of four) of cynomolgus and rhesus macaques survived, respectively, when treatment was initiated after detection of viremia at 3 dpi. Fifty percent (two of four) of the cynomolgus macaques survived when Ad-IFN was given at 1 dpi, followed by ZMAb starting at 4 dpi, after positive diagnosis. The treatment was able to suppress viremia reaching ~10(5) TCID50 (median tissue culture infectious dose) per milliliter, leading to survival and robust specific immune responses. This study describes conditions capable of saving 100% of EBOV-infected NHPs when initiated after the presence of detectable viremia along with symptoms.
Ebola virus (EBOV) is considered one of the most aggressive infectious agents and is capable of causing death in humans and nonhuman primates (NHPs) within days of exposure. Recent strategies have succeeded in preventing acquisition of infection in NHPs after treatment; however, these strategies are only successful when administered before or minutes after infection. The present work shows that a combination of three neutralizing monoclonal antibodies (mAbs) directed against the Ebola envelope glycoprotein (GP) resulted in complete survival (four of four cynomolgus macaques) with no apparent side effects when three doses were administered 3 days apart beginning at 24 hours after a lethal challenge with EBOV. The same treatment initiated 48 hours after lethal challenge with EBOV resulted in two of four cynomolgus macaques fully recovering. The survivors demonstrated an EBOV-GP-specific humoral and cell-mediated immune response. These data highlight the important role of antibodies to control EBOV replication in vivo, and support the use of mAbs against a severe filovirus infection.
BACKGROUND:Mucosal vaccination can offer several advantages over conventional intramuscular immunization to protect against Ebola virus (EBOV) infection, such as immune protection at sites of viral entry into susceptible individuals, and can be administered using needle-free devices.METHODS:The present study evaluated oral and nasal vaccination of mice with human adenovirus serotype 5 (Ad) expressing the Zaire ebolavirus glycoprotein (Ad-ZGP) in terms of their protection against and underlying immune responses to EBOV.RESULTS:Similar to intramuscular administration, oral or nasal vaccination of mice with Ad-ZGP fully protected the mice against a lethal challenge with mouse-adapted EBOV. Both T and B cell responses developed in mice receiving oral or nasal vaccination in different body compartments, indicating qualitative improvement of the immune response after mucosal immunization, compared with intramuscular vaccination.CONCLUSIONS:Overall, the breadth of the immune response noted after nasal or oral immunization, including stimulation of CD8+ T cells or effector memory T cells from the gastrointestinal tract or the lungs, was superior to that noted after intramuscular administration of the vaccine. The present study showed that adenovirus-based vaccine is effective against EBOV infection in mice after oral and nasal immunization.
Ebola hemorrhagic fever virus can be modeled in different animal species such as mice, Guinea pigs and nonhuman primates. Several vaccine strategies were evaluated using DNA-, protein-based and/or viral vectors and found to protect mice against challenge with a lethal dose of mouse-adapted Ebola virus. However, only a few strategies involving DNA, Adenovirus or Vesicular Stomatitis virus (VSV), alone or in combination, succeeded at protecting nonhuman primates from Ebola virus aggressive replication. Ebola virus offers thus a unique disease model for the evaluation and testing of different vaccine platforms and/or strategies that can be screened in vivo in conditions of low to high stringency. One major limitation of using Ebola virus as a disease model is the requirement to manipulate the virus in a biosafety level 4 environment (BSL-4) which makes in vitro and in vivo testing less accessible and more time consuming. We compared four different methodologies to evaluate the levels of neutralizing antibody (NAB) from sera of nonhuman primates vaccinated with VSV- or Adenovirus-based vaccine expressing the Ebola envelope glycoprotein (EboGP). The first strategy evaluates neutralization of wild-type Ebola virus by immunoplaques; the second evaluates neutralization of Ebola expressing EGFP inserted as an additional gene in the viral genome; the third evaluates inhibition of plaque formation by an EboGP-pseudotyped VSV virus and the fourth evaluates neutralization of an EboGP-pseudotyped HIV vector. The first two strategies are using a replication competent Ebola virus and were thus performed in a BSL4 laboratory while the other two, using a replication competent VSV or replication defective HIV vector, were done in an enhanced BSL2 environment. Results indicate that the two methodologies using replication competent Ebola virus are slightly more sensitive than with pseudotyped VSV or HIV vector. Ebola expressing EGFP was found the method of choice in the BSL4 laboratory since it can be performed in 48 hours (instead of 6 days for immunoplaque assay) and does not depend on the sensitivity of an antibody/antigen reaction. Overall, each protocol offers advantages and inconveniences that will be discussed. James Wilson had equity in Targeted Genetics at the moment of the study.