Lessons Learned from the Design, Construction, and Commissioning of a Retrofitted Arthropod Containment Level 3 Insectary.

Arthropods are vectors for many pathogens that significantly harm human and animal health globally, and research into vector-borne diseases is of critical public health importance. Arthropods present unique risks for containment, and therefore insectary facilities are essential to the safe handling of arthropod-borne hazards. In 2018, the School of Life Sciences at Arizona State University (ASU) began the process to build a level 3 arthropod containment (ACL-3) facility. Even with the COVID-19 pandemic, it took more than 4 years for the insectary to be granted a Certificate of Occupancy. At the request of the ASU Environmental Health and Safety team, Gryphon Scientific, an independent team with biosafety and biological research expertise, studied the project lifecycle through the design, construction, and commissioning of the ACL-3 facility with the goal of identifying lessons learned from the delayed timeline. These lessons learned convey insight into best practices for assessing potential facility sites, anticipating challenges with retrofitted construction, preparing for commissioning, equipping the project team with necessary expertise and expectations, and supplementing the gaps in available containment guidance. Several unique mitigations designed by the ASU team to address research risks not specifically addressed in the American Committee of Medical Entomology Arthropod Containment Guidelines are also described. Completion of the ACL-3 insectary at ASU was delayed, but the team thoroughly assessed potential risks and enabled appropriate practices for the safe handling of arthropod vectors. These efforts will enhance future ACL-3 construction by helping to avoid similar setbacks and streamlining progress from concept to operation.

The COVID-19 Pandemic Response: Biosafety Perspectives from a Large Research and Teaching Institution.

Introduction: Although the COVID-19 pandemic began over 2 years ago, responses from institutions have not been thoroughly documented. Because of constantly evolving guidance from regulatory and public health agencies, the traditional evidence-based risk assessment process was disrupted. It took time to obtain enough actionable information about the novel SARS-CoV-2 virus and its transmission to be able to inform decision making and consistently make accurate recommendations. Objectives: The primary objective of this article is to detail the actions in chronological order taken by the biosafety team at Arizona State University in response to the COVID-19 pandemic. Methods: This article includes a chronicling of actual experiences and observations with a retrospective review and analysis of the actions taken to document and share lessons learned to guard against future pandemics. Specific infection control practices, such as measuring saliva droplets from dropped test tubes, are described and different COVID-19 testing and vaccination site designs are evaluated. Results: The biosafety team helped collect more than 304,000 saliva samples, deliver 15,528 vaccinations, safely manage more than 170,000 gallons of biohazardous waste, and oversee the pandemic response inventory. The team also conducted inspections, developed safety procedures, and reviewed research protocols. Conclusions: The COVID-19 pandemic required safety professionals to re-envision how they perform their work, not only at their place of employment, but also within their communities and at their homes. This presented a challenge to balance inquiry and the scientific process against the urgent need for understanding changing pandemic dynamics and information and developing new best practices.

Remote Ischemic Conditioning Reduced Acute Lung Injury After Traumatic Brain Injury in the Mouse.

ABSTRACT: Traumatic brain injury (TBI) can induce acute lung injury (ALI). The exact pathomechanism of TBI-induced ALI is poorly understood, limiting treatment options. Remote ischemic conditioning (RIC) can mitigate detrimental outcomes following transplants, cardiac arrests, and neurological injuries. In this study, we hypothesized that RIC would reduce TBI-induced ALI by regulating the sphingosine-1-phosphate (S1P)-dependent pathway, a central regulator of endothelial barrier integrity, lymphocyte, and myokine trafficking. Male mice were subjected to either diffuse TBI by midline fluid percussion or control sham injury and randomly assigned among four groups: sham, TBI, sham RIC, or TBI RIC; RIC was performed 1 h prior to TBI. Mice were euthanized at 1-h postinjury or 7 days post-injury (DPI) and lung tissue, bronchoalveolar lavage (BAL) fluid, and blood were collected. Lung tissue was analyzed for histopathology, irisin myokine levels, and S1P receptor levels. BAL fluid and blood were analyzed for cellularity and myokine/S1P levels, respectively. One-hour postinjury, TBI damaged lung alveoli and increased neutrophil infiltration; RIC preserved alveoli. BAL from TBI mice had more neutrophils and higher neutrophil/monocyte ratios compared with sham, where TBI RIC mice showed no injury-induced change. Further, S1P receptor 3 and irisin-associated protein levels were significantly increased in the lungs of TBI mice compared with sham, which was prevented by RIC. However, there was no RIC-associated change in plasma irisin or S1P. At 7 DPI, ALI in TBI mice was largely resolved, with evidence for residual lung pathology. Thus, RIC may be a viable intervention for TBI-induced ALI to preserve lung function and facilitate clinical management.

S1PR1-Associated Molecular Signature Predicts Survival in Patients with Sepsis.

BACKGROUND: Sepsis is a potentially life-threatening complication of an underlying infection that quickly triggers tissue damage in multiple organ systems. To date, there are no established useful prognostic biomarkers for sepsis survival prediction. Sphingosine-1-phosphate (S1P) and its receptor S1P receptor 1 (S1PR1) are potential therapeutic targets and biomarkers for sepsis, as both are active regulators of sepsis-relevant signaling events. However, the identification of an S1PR1-related gene signature for prediction of survival in sepsis patients has yet to be identified. This study aims to find S1PR1-associated biomarkers which could predict the survival of patients with sepsis using gene expression profiles of peripheral blood to be used as potential prognostic and diagnostic tools. METHODS: Gene expression analysis from sepsis patients enrolled in published datasets from Gene Expression Omnibus was utilized to identify both S1PR1-related genes (co-expression genes or functional-related genes) and sepsis survival-related genes. RESULTS: We identified 62-gene and 16-gene S1PR1-related molecular signatures (SMS) associated with survival of patients with sepsis in discovery cohort. Both SMS genes are significantly enriched in multiple key immunity-related pathways that are known to play critical roles in sepsis development. Meanwhile, the SMS performs well in a validation cohort containing sepsis patients. We further confirmed our SMSs, as newly developed gene signatures, perform significantly better than random gene signatures with the same gene size, in sepsis survival prognosis. CONCLUSIONS: Our results have confirmed the significant involvement of S1PR1-dependent genes in the development of sepsis and provided new gene signatures for predicting survival of sepsis patients.

Decreasing recurrent bowel obstructions, improving quality of life with physiotherapy: Controlled study.

AIM: To compare (1) quality of life and (2) rate of recurrent small bowel obstructions (SBO) for patients treated with novel manual physiotherapy vs no treatment. METHODS: One hundred and three subjects (age 19-89) with a history of recurrent adhesive SBO were treated with a manual physiotherapy called the Clear Passage Approach (CPA) which focused on decreasing adhesive crosslinking in abdominopelvic viscera. Pre- and post-therapy data measured recurring obstructions and quality of life, using a validated test sent 90 d after therapy. Results were compared to 136 untreated control subjects who underwent the same measurements for subjects who did not receive any therapy, which is the normal course for patients with recurring SBO. Comparison of the groups allowed us to assess changes when the physiotherapy was added as an adjunct treatment for patients with recurring SBO. RESULTS: Despite histories of more prior hospitalizations, obstructions, surgeries, and years impacted by bowel issues, the 103 CPA-treated subjects reported a significantly lower rate of repeat SBO than 136 untreated controls (total obstructions P = 0.0003; partial obstructions P = 0.0076). Subjects treated with the therapy demonstrated significant improvements in five of six total domains in the validated Small Bowel Obstruction Questionnaire (SBO-Q). Domains of diet, pain, gastrointestinal symptoms, quality of life (QOL) and pain severity when compared to post CPA treatment were significantly improved (P < 0.0001). The medication domain was not changed in the CPA treated group (P = 0.176). CONCLUSION: CPA physical therapy was effective for patients with adhesive SBO with significantly lower recurrence rate, improvement in reported symptoms and overall quality of life of subjects.

Treating Small Bowel Obstruction with a Manual Physical Therapy: A Prospective Efficacy Study.

Small bowel obstructions (SBOs) caused by adhesions are a common, often life-threatening postsurgical complication with few treatment options available for patients. This study examines the efficacy of a manual physical therapy treatment regimen on the pain and quality of life of subjects with a history of bowel obstructions due to adhesions in a prospective, controlled survey based study. Changes in six domains of quality of life were measured via ratings reported before and after treatment using the validated Small Bowel Obstruction Questionnaire (SBO-Q). Improvements in the domains for pain (p = 0.0087), overall quality of life (p = 0.0016), and pain severity (p = 0.0006) were significant when average scores before treatment were compared with scores after treatment. The gastrointestinal symptoms (p = 0.0258) domain was marginally significant. There was no statistically significant improvement identified in the diet or medication domains in the SBO-Q for this population. Significant improvements in range of motion in the trunk (p ≤ 0.001), often limited by adhesions, were also observed for all measures. This study demonstrates in a small number of subjects that this manual physical therapy protocol is an effective treatment option for patients with adhesive small bowel obstructions as measured by subject reported symptoms and quality of life.

Ten-year Retrospective Study on the Efficacy of a Manual Physical Therapy to Treat Female Infertility.

BACKGROUND: Female infertility is a complex issue encompassing a wide variety of diagnoses, many of which are caused or affected by adhesions. OBJECTIVES: The study intended to examine the rates of successful treatment of infertile women using a protocol of manual physical therapy to address underlying adhesive disease leading to infertility. Methods • The research team designed a retrospective chart review. SETTING: The study took place in a private physical therapy clinic. PARTICIPANTS: Participants were 1392 female patients who were treated at the clinic between the years of 2002 and 2011. They had varying diagnoses of infertility, including occluded fallopian tubes, hormonal dysfunction, and endometriosis, and some women were undergoing in vitro fertilization (IVF). Intervention • All patients underwent whole-body, patient-centered treatments that used a protocol of manual physical therapy, which focused on restoring mobility and motility to structures affecting reproductive function. OUTCOME MEASURES: Improvements demonstrated in the condition(s) causing infertility were measured by improvements in tubal patency and/or improved hormone levels or by pregnancy. Results • The results included a 60.85% rate of clearing occluded fallopian tubes, with a 56.64% rate of pregnancy in those patients. Patients with endometriosis experienced a 42.81% pregnancy rate. The success rate was 49.18% for lowering elevated levels of follicle stimulating hormone (FSH), with a 39.34% pregnancy rate in that group, and 53.57% of the women with polycystic ovarian syndrome (PCOS) achieved pregnancy. The reported pregnancy rate for patients who underwent IVF after the therapy was 56.16%. The results also suggested that the treatment was effective for patients with premature ovarian failure (POF). CONCLUSION: The manual physical therapy represented an effective, conservative treatment for women diagnosed as infertile due to mechanical causes, independent of the specific etiology.

Ten-year Retrospective Study on the Efficacy of a Manual Physical Therapy to Treat Female Infertility.

Background • Female infertility is a complex issue encompassing a wide variety of diagnoses, many of which are caused or affected by adhesions. Objectives • The study intended to examine the rates of successful treatment of infertile women using a protocol of manual physical therapy to address underlying adhesive disease leading to infertility. Methods • The research team designed a retrospective chart review. Setting • The study took place in a private physical therapy clinic. Participants • Participants were 1392 female patients who were treated at the clinic between the years of 2002 and 2011. They had varying diagnoses of infertility, including occluded fallopian tubes, hormonal dysfunction, and endometriosis, and some women were undergoing in vitro fertilization (IVF). Intervention • All patients underwent whole-body, patient-centered treatments that used a protocol of manual physical therapy, which focused on restoring mobility and motility to structures affecting reproductive function. Outcome Measures • Improvements demonstrated in the condition(s) causing infertility were measured by improvements in tubal patency and/or improved hormone levels or by pregnancy. Results • The results included a 60.85% rate of clearing occluded fallopian tubes, with a 56.64% rate of pregnancy in those patients. Patients with endometriosis experienced a 42.81% pregnancy rate. The success rate was 49.18% for lowering elevated levels of follicle stimulating hormone (FSH), with a 39.34% pregnancy rate in that group, and 53.57% of the women with polycystic ovarian syndrome (PCOS) achieved pregnancy. The reported pregnancy rate for patients who underwent IVF after the therapy was 56.16%. The results also suggested that the treatment was effective for patients with premature ovarian failure (POF). Conclusion • The manual physical therapy represented an effective, conservative treatment for women diagnosed as infertile due to mechanical causes, independent of the specific etiology.

Scoring the collective effects of SNPs: association of minor alleles with complex traits in model organisms.

It has long been assumed that most parts of a genome and most genetic variations or SNPs are non-functional with regard to reproductive fitness. However, the collective effects of SNPs have yet to be examined by experimental science. We here developed a novel approach to examine the relationship between traits and the total amount of SNPs in panels of genetic reference populations. We identified the minor alleles (MAs) in each panel and the MA content (MAC) that each inbred strain carried for a set of SNPs with genotypes determined in these panels. MAC was nearly linearly linked to quantitative variations in numerous traits in model organisms, including life span, tumor susceptibility, learning and memory, sensitivity to alcohol and anti-psychotic drugs, and two correlated traits poor reproductive fitness and strong immunity. These results suggest that the collective effects of SNPs are functional and do affect reproductive fitness.

Protective properties of vaccinia virus-based vaccines: skin scarification promotes a nonspecific immune response that protects against orthopoxvirus disease.

The process of vaccination introduced by Jenner generated immunity against smallpox and ultimately led to the eradication of the disease. Procedurally, in modern times, the virus is introduced into patients via a process called scarification, performed with a bifurcated needle containing a small amount of virus. What was unappreciated was the role that scarification itself plays in generating protective immunity. In rabbits, protection from lethal disease is induced by intradermal injection of vaccinia virus, whereas a protective response occurs within the first 2 min after scarification with or without virus, suggesting that the scarification process itself is a major contributor to immunoprotection. importance: These results show the importance of local nonspecific immunity in controlling poxvirus infections and indicate that the process of scarification should be critically considered during the development of vaccination protocols for other infectious agents.

Decreasing adhesions and avoiding further surgery in a pediatric patient involved in a severe pedestrian versus motor vehicle accident.

In this case study, we report the use of manual physical therapy in a pediatric patient experiencing complications from a life-threatening motor vehicle accident that necessitated 19 surgeries over the course of 12 months. Post-surgical adhesions decreased the patient's quality of life. He developed multiple medical conditions including recurrent partial bowel obstructions and an ascending testicle. In an effort to avoid further surgery for bowel obstruction and the ascending testicle, the patient was effectively treated with a manual physical therapy regimen focused on decreasing adhesions. The therapy allowed return to an improved quality of life, significant decrease in subjective reports of pain and dysfunction, and apparent decreases in adhesive processes without further surgery, which are important goals for all patients, but especially for pediatric patients.

Development and Validation of a Questionnaire to Measure Serious and Common Quality of Life Issues for Patients Experiencing Small Bowel Obstructions.

A validated questionnaire to assess the impact of small bowel obstructions (SBO) on patients' quality of life was developed and validated. The questionnaire included measurements for the impact on the patients' quality of life in respect to diet, pain, gastrointestinal symptoms and daily life. The questionnaire was validated using 149 normal subjects. Chronbach alpha was 0.86. Test retest reliability was evaluated with 72 normal subjects, the correlation coefficient was 0.93. Discriminate validity was determined to be significant using the normal subject questionnaires and 10 questionnaires from subjects with recurrent SBO. Normative and level of impact for each measured domain were established using one standard deviation from the mean in the normal population and clinical relevance. This questionnaire is a valid and reliable instrument to measure the impact of SBO on a patient's quality of life related to recurrent SBOs; therefore establishing a mechanism to monitor and quantify changes in quality of life over time.

Manual Physical Therapy for Non-Surgical Treatment of Adhesion-Related Small Bowel Obstructions: Two Case Reports.

BACKGROUND: Adhesion formation is a widely acknowledged risk following abdominal or pelvic surgery. Adhesions in the abdomen or pelvis can cause or contribute to partial or total small bowel obstruction (SBO). These adhesions deter or prevent the passage of nutrients through the digestive tract, and may bind the bowel to the peritoneum, or other organs. Small bowel obstructions can quickly become life-threatening, requiring immediate surgery to resect the bowel, or lyse any adhesions the surgeon can safely access. Bowel repair is an invasive surgery, with risks including bowel rupture, infection, and peritonitis. An additional risk includes the formation of new adhesions during the healing process, creating the potential for subsequent adhesiolysis or SBO surgeries. OBJECTIVE: Report the use of manual soft tissue physical therapy for the reversal of adhesion-related partial SBOs, and create an initial inquiry into the possibility of nonsurgical lysis of adhesions. CASE REPORTS: Two patients presenting with SBO symptoms due to abdominal adhesions secondary to abdominal and pelvic surgery were treated with manual soft tissue physical therapy focused on decreasing adhesions. CONCLUSIONS: Successful treatment with resolution of symptom presentation of partial SBO and sustained results were observed in both patients treated.

The NYCBH vaccinia virus deleted for the innate immune evasion gene, E3L, protects rabbits against lethal challenge by rabbitpox virus.

Vaccinia virus deleted for the innate immune evasion gene, E3L, has been shown to be highly attenuated and yet induces a protective immune response against challenge by homologous virus in a mouse model. In this manuscript the NYCBH vaccinia virus vaccine strain was compared to NYCBH vaccinia virus deleted for E3L (NYCBHΔE3L) in a rabbitpox virus (RPV) challenge model. Upon scarification, both vaccines produced a desired skin lesion, although the lesion produced by NYCBHΔE3L was smaller. Both vaccines fully protected rabbits against lethal challenge by escalating doses of RPV, from 10LD(50) to 1000LD(50). A single dose of NYCBHΔE3L protected rabbits from weight loss, fever, and clinical symptoms following the lowest dose challenge of 10LD(50), however it allowed a moderate level of RPV replication at the challenge site, some spread to external skin and mucosal surfaces, and increased numbers of secondary lesions as compared to vaccination with NYCBH. Alternately, two doses of NYCBHΔE3L fully protected rabbits from weight loss, fever, and clinical symptoms, following challenge with 100-1000LD(50) RPV, and it prevented development of secondary lesions similar to protection seen with NYCBH. Finally, vaccination with either one or two doses of NYCBHΔE3L resulted in similar neutralizing antibody titers following RPV challenge as compared to titers obtained by vaccination with NYCBH. These results support the efficacy of the attenuated NYCBHΔE3L in protection against an orthologous poxvirus challenge.

An efficient method for generating poxvirus recombinants in the absence of selection.

The use of selectable markers (ecogpt) and selection pressures to aid in detection of poxvirus (Vaccinia, VV) recombinants has been implicated in the unintended introduction of second site mutations. We have reinvestigated the use of the helper virus system described by Scheiflinger et al. and adapted by Yao and Evans which produces recombinants at a high frequency in the absence of any selection, at a rate of 6­100%. Our system uses fowlpox virus (FPV) as the infectious helper virus which in infected cells provides the enzymatic apparatus for transcription and replication of a purified, transfected VV genome and for recombination with a second transfected PCR generated DNA fragment. To optimize the system, a PCR DNA fragment was generated that contained poxvirus promoter driven gfp and lacZ genes inserted within the coding sequences of the viral thymidine kinase gene. This PCR fragment was co-transfected together with VV genomic DNA. Recombinant VV was identified by plaquing the mixture on cells non-permissive for FPV and selection of green fluorescent or LacZ positive recombinant vaccinia plaques. The system was optimized using FPV permissive cells (CEF) and non-permissive cells (A549, CV-1) for both the initial infection/transfection and the subsequent selection. Up to 70% of the progeny vaccinia virus contained the gfp/LacZ insertion. In order to test for the presence of FPV/VV intertypic recombinants or other unintended mutations, recombinant wtVV (RwtVV) was regenerated from the gfp/LacZ viruses and evaluated by RFLP analysis and pathogenesis in animals. While all RwtVVs were viable in cell culture, in many of the RwtVV isolates, RFLP differences were noted and while some recombinant viruses exhibited wild type behavior in mice, a wide range of virulence indicative of unintended changes suggests that mutants created by "rescue" systems require careful analysis particularly before use for in vivo studies employing animal models.

Efficacy of CMX001 as a post exposure antiviral in New Zealand White rabbits infected with rabbitpox virus, a model for orthopoxvirus infections of humans.

CMX001, a lipophilic nucleotide analog formed by covalently linking 3-(hexdecyloxy)propan-1-ol to cidofovir (CDV), is being developed as a treatment for smallpox. In the absence of human cases of smallpox, new treatments must be tested for efficacy in animal models. Previously, we demonstrated the efficacy of CMX001 in protecting New Zealand White rabbits from mortality following intradermal infection with rabbitpox virus as a model for smallpox, monkeypox and for treatment of adverse reactions to smallpox vaccination. Here we extend these studies by exploring different dosing regimens and performing randomized, blinded, placebo-controlled studies. In addition, because rabbitpox virus can be transmitted via naturally generated aerosols (animal to animal transmission), we report on studies to test the efficacy of CMX001 in protecting rabbits from lethal rabbitpox virus disease when infection occurs by animal to animal transmission. In all cases, CMX001 treatment was initiated at the onset of observable lesions in the ears to model the use of CMX001 as a treatment for symptomatic smallpox. The results demonstrate that CMX001 is an effective treatment for symptomatic rabbitpox virus infection. The rabbitpox model has key similarities to human smallpox including an incubation period, generalized systemic disease, the occurrence of lesions which may be used as a trigger for initiating therapy, and natural animal to animal spread, making it an appropriate model.

Efficacy of CMX001 as a prophylactic and presymptomatic antiviral agent in New Zealand white rabbits infected with rabbitpox virus, a model for orthopoxvirus infections of humans.

CMX001, a lipophilic nucleotide analog formed by covalently linking 3-(hexdecyloxy)propan-1-ol to cidofovir (CDV), is being developed as a treatment for smallpox. CMX001 has dramatically increased potency versus CDV against all dsDNA viruses and, in contrast to CDV, is orally available and has shown no evidence of nephrotoxicity in healthy volunteers or severely ill transplant patients to date. Although smallpox has been eliminated from the environment, treatments are urgently being sought due to the risk of smallpox being used as a bioterrorism agent and for monkeypox virus, a zoonotic disease of Africa, and adverse reactions to smallpox virus vaccinations. In the absence of human cases of smallpox, new treatments must be tested for efficacy in animal models. Here we first review and discuss the rabbitpox virus (RPV) infection of New Zealand White rabbits as a model for smallpox to test the efficacy of CMX001 as a prophylactic and early disease antiviral. Our results should also be applicable to monkeypox virus infections and for treatment of adverse reactions to smallpox vaccination.

Roles of vaccinia virus genes E3L and K3L and host genes PKR and RNase L during intratracheal infection of C57BL/6 mice.

The importance of the 2'-5' oligoadenylate synthetase (OAS)/RNase L and double-stranded RNA (dsRNA)-dependent protein kinase (PKR) pathways in host interferon induction resulting from virus infection in response to dsRNA has been well documented. In poxvirus infections, the interactions between the vaccinia virus (VV) genes E3L and K3L, which target RNase L and PKR, respectively, serve to prevent the induction of the dsRNA-dependent induced interferon response in cell culture. To determine the importance of these host genes in controlling VV infections, mouse single-gene knockouts of RNase L and PKR and double-knockout mice were studied following intratracheal infection with VV, VVΔK3L, or VVΔE3L. VV caused lethal disease in all mouse strains. The single-knockout animals were more susceptible than wild-type animals, while the RNase L(-/-) PKR(-/-) mice were the most susceptible. VVΔE3L infections of wild-type mice were asymptomatic, demonstrating that E3L plays a critical role in controlling the host immune response. RNase L(-/-) mice showed no disease, whereas 20% of the PKR(-/-) mice succumbed at a dose of 10(8) PFU. Lethal disease was routinely observed in RNase L(-/-) PKR(-/-) mice inoculated with 10(8) PFU of VVΔE3L, with a distinct pathology. VVΔK3L infections exhibited no differences in virulence among any of the mouse constructs, suggesting that PKR is not the exclusive target of K3L. Surprisingly, VVΔK3L did not disseminate to other tissues from the lung. Hence, the cause of death in this model is respiratory disease. These results also suggest that an unanticipated role of the K3L gene is to facilitate virus dissemination.

Rabbitpox virus and vaccinia virus infection of rabbits as a model for human smallpox.

The threat of smallpox release and use as a bioweapon has encouraged the search for new vaccines and antiviral drugs, as well as development of new small-animal models in which their efficacy can be determined. Here, we reinvestigate a rabbit model in which the intradermal infection of rabbits with very low doses of either rabbitpox virus (RPV) or vaccinia virus Western Reserve (VV-WR) recapitulates many of the clinical features of human smallpox. Following intradermal inoculation with RPV, rabbits develop systemic disease characterized by extensive viremia, numerous secondary lesions on the skin and mucocutaneous tissues, severe respiratory disease, death by 9 days postinfection, and, importantly, natural aerosol transmission between animals. Contrary to previous reports, intradermal infection with VV-WR also resulted in a very similar lethal systemic disease in rabbits, again with natural aerosol transmission between animals. When sentinel and index animals were cohoused, transmission rates approached 100% with either virus, with sentinel animals exhibiting a similar, severe disease. Lower rates of transmission were observed when index and sentinel animals were housed in separate cages. Sentinel animals infected with RPV with one exception succumbed to the disease. However, the majority of VV-WR-infected sentinel animals, while becoming seriously ill, survived. Finally, we tested the efficacy of the drug 1-O-hexadecyloxypropyl-cidofovir in the RPV/rabbit model and found that an oral dose of 5 mg/kg twice a day for 5 days beginning 1 day before infection was able to completely protect rabbits from lethal disease.