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Aim: Passive immunisation with palivizumab is recommended in many countries for children with haemodynamically significant cardiac disease. We trialled respiratory syncytial virus (RSV) immunoprophylaxis in such infants during 2008–2009.Methods: We identified all RSV admissions between 2005–2009 and examined all patients with significant cardiac disease who received palivizumab in 2008–2009.Results: Infants with symptomatic cardiac disease had a more complicated course of RSV bronchiolitis with longer hospital stay, more frequent intensive care admission, longer intensive care stay and were more likely to receive respiratory support (all P < 0.05). One hundred seventeen infants with symptomatic cardiac disease received palivizumab. Of these, two (1.7%) required admission for RSV bronchiolitis. Overall, there was a reduction in admission of infants with symptomatic cardiac disease with RSV bronchiolitis in 2008–2009 (2% per year) compared with 2005–2007 (5–9% per year; P < 0.03). The number of patients with symptomatic cardiac disease who required intensive care for RSV bronchiolitis in the same period was unchanged, as a number presented to our service with RSV infection prior to commencing immunoprophylaxis or having had their cardiac diagnosis made in other centres.Conclusions: Compared with other infants, those with haemodynamically significant cardiac disease have a more complicated course of illness with RSV bronchiolitis. In these infants, palivizumab reduced the number of hospitalisations because of RSV. Cohorting patients for maximal palivizumab use reduced overall cost. To significantly impact on intensive care admissions overall, immunoprophylaxis should be considered at a regional level. [ABSTRACT FROM AUTHOR]

High blood pressure (BP) in childhood is a recognised precursor of elevated cardiovascular risk in adulthood. Brachial BP is normally used for clinical decision making, but central BP may be a better marker of pressure load on the heart. There is a paucity of validated non-invasive, automated devices for estimating central BP in children and adolescents. In this study, we compared the WatchBP Office Central (a Type 2 central pressure estimation device) against a high-fidelity micromanometer in the ascending aorta of anaesthetised patients undergoing clinically-indicated catheterisation (n = 15, age 4-16 years). As a secondary aim, central systolic BP (cSBP) was also compared to two non-invasive estimation methods in 34 awake patients undergoing routine cardiac MRI (age 10-18 years). WatchBP substantially overestimated cSBP compared to the intra-arterial gold-standard reference (26.1 ± 7.4 mmHg), and recruitment was terminated at n = 11 (included in the analysis) due to high statistical certainty that the device would not pass the validation criteria of 5±8 mmHg. WatchBP cSBP was also substantially higher than values obtained from a phase contrast MRI method (11.8 ± 7.9 mmHg) and the SphygmoCor XCEL (13.5 ± 8.9 mmHg) in the awake patient group, which translate to 21-23 mmHg on average after accounting for known/estimated biases in these non-invasive comparators. Compared with invasive central diastolic and systolic BPs, the brachial measures from WatchBP yielded errors of 0.1 ± 5.6 and 12.5 ± 6.0 mmHg respectively. We conclude that the WatchBP substantially overestimates cSBP in children and adolescents. These findings reinforce the need for central BP-measuring devices to be further developed and validated in this population., Competing Interests: Competing interests: JPM is a consultant to Tournicare Pty. Ltd. (no relation to the present work) and is the recipient of a grant from Uscom Ltd. to assess another central blood pressure measurement device in children and adolescents. All other authors have no conflicts to report. Ethical approval: This study was conducted in accordance with the Declaration of Helsinki and was approved by the Human Research Ethics Committee of the Royal Children’s Hospital, Melbourne, Australia (HRECs: 35202 and 37135)., (© 2024. The Author(s).)

These first Australian National Standards of Care for Childhood-onset Heart Disease (CoHD Standards) have been developed to inform the healthcare requirements for CoHD services and enable all Australian patients, families and carers impacted by CoHD (paediatric CoHD and adult congenital heart disease [ACHD]) to live their best and healthiest lives. The CoHD Standards are designed to provide the clarity and certainty required for healthcare services to deliver excellent, comprehensive, inclusive, and equitable CoHD care across Australia for patients, families and carers, and offer an iterative roadmap to the future of these services. The CoHD Standards provide a framework for excellent CoHD care, encompassing key requirements and expectations for whole-of-life, holistic and connected healthcare service delivery. The CoHD Standards should be implemented in health services in conjunction with the National Safety and Quality Health Service Standards developed by the Australian Commission on Safety and Quality in Health Care. All healthcare services should comply with the CoHD Standards, as well as working to their organisation's or jurisdiction's agreed clinical governance framework, to guide the implementation of structures and processes that support safe care., Competing Interests: Statement of Competing Interests The authors declare no known competing interests., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Competing Interests: Funding Support and Author Disclosures Dr Lee is supported by MRFF Investigator grant 1197307. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

There is an enduring requirement to develop animal models of COVID-19 to assess the efficacy of vaccines and therapeutics that can be used to treat the disease in humans. In this study, six marmosets were exposed to a small particle aerosol (1-3 µm) of SARS-CoV-2 VIC01 that delivered the virus directly to the lower respiratory tract. Following the challenge, marmosets did not develop clinical signs, although a disruption to the normal diurnal temperature rhythm was observed in three out of six animals. Early weight loss and changes to respiratory pattern and activity were also observed, yet there was limited evidence of viral replication or lung pathology associated with infection. There was a robust innate immunological response to infection, which included an early increase in circulating neutrophils and monocytes and a reduction in the proportion of circulating T-cells. Expression of the ACE2 receptor in respiratory tissues was almost absent, but there was ubiquitous expression of TMPRSS2. The results of this study indicate that exposure of marmosets to high concentrations of aerosolised SARS-CoV-2 did not result in the development of clear, reproducible signs of COVID-19.

Background: Central aortic SBP (cSBP) may have superior prognostic value compared with peripheral SBP (pSBP), but noninvasive cSBP measurement techniques have not been formally validated in children and adolescents., Method: This study assessed the accuracy of two automated devices and the radial tonometry/transfer function method (RT-TF) for estimating central pressures and pulse pressure amplification (PPA) in this population, with adherence to validation guidelines for central pressure devices. In 69 children/adolescents aged 3-18 years undergoing clinically indicated aortic catheterization, high fidelity ascending aortic cSBP was measured with a micromanometer-tipped wire and compared with values from SphygmoCor XCEL, Mobil-O-Graph (systolic/diastolic calibration, MoG-C1, or mean/diastolic calibration, MoG-C2) and RT-TF. Reference intra-arterial pSBP was derived from the tonometry pulse calibrated to central mean/diastolic pressures., Results: XCEL, MoG-C1 and MoG-C2 overestimated cSBP by 7.9 ± 6.8 mmHg (mean ± SD), 5.7 ± 10.3 mmHg, and 19.1 ± 14.9 mmHg, exceeding the validation cut-off (5 ± 8 mmHg). Brachial pSBP was also overestimated by XCEL (10.9 ± 8.4 mmHg) and Mobil-O-Graph (11.5 ± 12.3 mmHg). By contrast, central and brachial diastolic pressures were underestimated by the automated devices, albeit mostly within acceptable limits; pulse pressures were, therefore, substantially overestimated. Central-brachial PPA (4.5 ± 4.4 mmHg) was overestimated by XCEL (8.7 ± 3.2 mmHg) and MoG-C1 (11.1 ± 6.4 mmHg), but underestimated by MoG-C2 (-3.0 ± 6.6 mmHg). Given accurate pulse calibration, RT-TF achieved acceptable accuracy for cSBP (-0.2 ± 4.6 mmHg) and central-radial PPA (1.9 ± 5.1 mmHg)., Conclusion: In conclusion, XCEL and Mobil-O-Graph overestimated pSBP and cSBP in children and adolescents. cSBP can be obtained via the same transfer function used in adults, but accurate pressure pulse calibration is critical.Video Abstracts: http://links.lww.com/HJH/B222.

As the ongoing outbreak in the Democratic Republic of Congo illustrates, Ebola virus disease continues to pose a significant risk to humankind and this necessitates the continued development of therapeutic options. One option that warrants evaluation is that of defective genomes; these can potentially parasitize resources from the wild-type virus and may even be packaged for repeated co-infection cycles. Deletion and copy-back defective genomes have been identified and reported in the literature. As a crude, mixed preparation these were found to have limiting effects on cytopathology. Here we have used synthetic virology to clone and manufacture two deletion defective genomes. These genomes were tested with Ebola virus using in vitro cell culture and shown to inhibit viral replication; however, and against expectations, the defective genomes were not released in biologically significant numbers. We propose that EBOV might have yet unknown mechanisms to prevent parasitisation by defective interfering particles beyond the known mechanism that prevents sequential infection of the same cell. Understanding this mechanism would be necessary in any development of a defective interfering particle-based therapy., (Copyright © 2020 Smither, Garcia-Dorival, Eastaugh, Findlay, O'Brien, Carruthers, Williamson, Molina-París, Hiscox and Laws.)

Objectives: D-transposition of the great arteries and l-transposition of the great arteries with ventricular septal defect and left ventricular outflow tract obstruction are complex biventricular congenital heart diseases for which decision-making regarding surgical strategy remains challenging. We investigated the intermediate-term outcomes of Fontan versus biventricular procedures in these patients., Methods: We analyzed 129 patients with d-transposition of the great arteries/ventricular septal defect/left ventricular outflow tract obstruction (n = 85) or l-transposition of the great arteries/ventricular septal defect/left ventricular outflow tract obstruction (n = 44) and 2 functional ventricles from Australia who had primary surgical management (29 Fontan, 100 biventricular repair) undertaken between 1990 and 2015., Results: Median operative age of patients was 2.9 years (range, 0.2-26.8 years). During a median follow-up of 6.2 years (range, 2 days to 25.8 years), 9 patients died after biventricular repair (3 early and 6 late deaths). One patient received a transplant 1.2 years after Fontan completion. Overall transplant-free survivals at 1, 5, 10, and 15 years were 95%, 93%, 92%, and 90%, respectively. Overall reintervention-free survivals at 1, 5, 10, and 15 years were 79%, 64%, 45%, and 29% respectively. Biventricular repair tended to be associated with a higher rate of death, transplantation, or reintervention than the Fontan pathway (hazard ratio, 1.83; 95% confidence interval, 0.90-3.71; P = .10). Some 73% of transplant-free survivors had New York Heart Association class I. Functional status was similar between the Fontan and biventricular groups., Conclusions: Intermediate-term outcomes were comparable between patients with d-transposition of the great arteries/ventricular septal defect/left ventricular outflow tract obstruction and patients with l-transposition of the great arteries/ventricular septal defect/left ventricular outflow tract obstruction. Both Fontan and biventricular pathways are associated with excellent mortality and functional outcomes. Biventricular patients have a greater risk of reintervention. The Fontan procedure is a viable option when anatomic risk factors preclude biventricular repair., (Copyright © 2019 The American Association for Thoracic Surgery. All rights reserved.)

Knowledge on haemostatic changes in humans infected with Ebola virus is limited due to safety concerns and access to patient samples. Ethical approval was obtained to collect plasma samples from patients in Sierra Leone infected with Ebola virus over time and samples were analysed for clotting time, fibrinogen, and D-dimer levels. Plasma from healthy volunteers was also collected by two methods to determine effect of centrifugation on test results as blood collected in Sierra Leone was not centrifuged. Collecting plasma without centrifugation only affected D-dimer values. Patients with Ebola virus disease had higher PT and APTT and D-dimer values than healthy humans with plasma collected in the same manner. Fibrinogen levels in patients with Ebola virus disease were normal or lower than values measured in healthy people. Clotting times and D-dimer levels were elevated during infection with Ebola virus but return to normal over time in patients that survived and therefore could be considered prognostic. Informative data can be obtained from plasma collected without centrifugation which could improve patient monitoring in hazardous environments.

Ebola virus (EBOV) in body fluids poses risk for virus transmission. However, there are limited experimental data for such matrices on the disinfectant efficacy against EBOV. We evaluated the effectiveness of disinfectants against EBOV in blood on surfaces. Only 5% peracetic acid consistently reduced EBOV titers in dried blood to the assay limit of quantification.

Background: A strategy of rehabilitation for pulmonary atresia, ventricular septal defect, and major aortopulmonary collateral arteries (PA/VSD/MAPCAs) comprises repetitive shunting and patching procedures of the central pulmonary arteries. We wanted to determine the feasibility and limitations of a strategy of rehabilitation., Methods: The outcomes of 37 consecutive patients operated from June 2003 to December 2014 for PA/VSD/MAPCAs were reviewed. The patients were directed to a rehabilitation strategy, except when they presented in heart failure with very large collaterals., Results: Four patients with very large MAPCAs underwent a one-stage repair with unifocalization of collateral vessels at a median age of 8.6 months. There was no mortality in this group after a median follow-up of 4.6 years. Following a strategy of staged rehabilitation, 33 patients had 2.01 ± 0.9 procedures before repair. Median age at primary shunting was 3.3 weeks (0.4 to 31.9 weeks). Repair rate was 73% (22 patients), at a median age of 1.7 years. Three patients (10%) were left palliated and 3 patients (10%) died. Median follow-up in this group was 4.5 years. Complementary procedures to the rehabilitation strategy consisted in pulmonary artery reconstruction in 25 patients (76%) and MAPCAs ligation in 7 patients (21%). Pulmonary balloon angioplasty was required in 12 patients (36%) and MAPCAs coil occlusion in 8 patients (24%)., Conclusions: A strategy of rehabilitation can be implemented in almost 90% of the cases, with a low mortality rate. Following this strategy, 73% of the patients can be successfully repaired., (Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Ebola virus Makona (EBOV-Makona; from the 2013-2016 West Africa outbreak) shows decreased virulence in an immune-deficient mouse model, compared with a strain from 1976. Unlike other filoviruses tested, EBOV-Makona may be slightly more virulent by the aerosol route than by the injected route, as 2 mice died following aerosol exposure, compared with no mortality among mice that received intraperitoneal injection of equivalent or higher doses. Although most mice did not succumb to infection, the detection of an immunoglobulin G antibody response along with observed clinical signs suggest that the mice were infected but able to clear the infection and recover. We hypothesize that this may be due to the growth rates and kinetics of the virus, which appear slower than that for other filoviruses and consequently give more time for an immune response that results in clearance of the virus. In this instance, the immune-deficient mouse model is unlikely to be appropriate for testing medical countermeasures against this EBOV-Makona stock but may provide insight into pathogenesis and the immune response to virus., (© Crown copyright 2016.)

Objective: Secundum atrial septal defect (ASD) is a common congenital heart defect. There is limited data on both early and late atrioventricular (AV) block post ASD closure. The aim of this study was to determine the incidence and risk factors of AV block associated with ASD closure., Methods: A retrospective analysis of all patients who underwent ASD closure either with a device or surgical method at the Royal Children's Hospital Melbourne between 1996 and 2010 was performed. Baseline demographics, procedural details and follow-up data were collected from medical records., Results: A total of 378 patients were identified; 242 in the device group and 136 in the surgical group. Fourteen patients (3.7%) had AV block (1 with second degree and 13 with first degree) at a median follow-up of 28 months; 11/242 (4.5%) in the device group and 3/135 (2.2%) in the surgical group (p=0.39). Six patients had new-onset AV block after ASD closure. In the device subgroup, patients with AV block at follow-up had a larger indexed device size compared with those without (22 (15-31) vs 18(7-38), p=0.02). Multivariate analysis revealed the presence of AV block either pre procedure or post procedure to be the only variables associated with late AV block., Conclusions: Late AV block in patients with repaired ASD is rare and most likely independent of the technique used. In the device subgroup, the only risk factor identified to be associated with late AV block was the presence of either preprocedural or postprocedural AV block, so long-term follow-up for these patients should be provided.

The West Africa Ebola virus (EBOV) outbreak has highlighted the need for effective disinfectants capable of reducing viral load in a range of sample types, equipment and settings. Although chlorine-based products are widely used, they can also be damaging to equipment or apparatus that needs continuous use such as aircraft use for transportation of infected people. Two aircraft cleaning solutions were assessed alongside two common laboratory disinfectants in a contact kill assay with EBOV on two aircraft relevant materials representative of a porous and non-porous surface. A decimal log reduction of viral titre of 4 is required for a disinfectant to be deemed effective and two of the disinfectants fulfilled this criteria under the conditions tested. One product, Ardrox 6092, was found to perform similarly to sodium hypochlorite, but as it does not have the corrosive properties of sodium hypochlorite, it could be an alternative disinfectant solution to be used for decontamination of EBOV on sensitive apparatus.

Rapid inactivation of Ebola virus (EBOV) is crucial for high-throughput testing of clinical samples in low-resource, outbreak scenarios. The EBOV inactivation efficacy of Buffer AVL (Qiagen) was tested against marmoset serum (EBOV concentration of 1 × 10(8) 50% tissue culture infective dose per milliliter [TCID50 · ml(-1)]) and murine blood (EBOV concentration of 1 × 10(7) TCID50 · ml(-1)) at 4:1 vol/vol buffer/sample ratios. Posttreatment cell culture and enzyme-linked immunosorbent assay (ELISA) analysis indicated that treatment with Buffer AVL did not inactivate EBOV in 67% of samples, indicating that Buffer AVL, which is designed for RNA extraction and not virus inactivation, cannot be guaranteed to inactivate EBOV in diagnostic samples. Murine blood samples treated with ethanol (4:1 [vol/vol] ethanol/sample) or heat (60°C for 15 min) also showed no viral inactivation in 67% or 100% of samples, respectively. However, combined Buffer AVL and ethanol or Buffer AVL and heat treatments showed total viral inactivation in 100% of samples tested. The Buffer AVL plus ethanol and Buffer AVL plus heat treatments were also shown not to affect the extraction of PCR quality RNA from EBOV-spiked murine blood samples., (© Crown copyright 2015.)

Ebola virus (EBOV) causes a highly infectious and lethal hemorrhagic fever in primates with high fatality rates during outbreaks and EBOV may be exploited as a potential biothreat pathogen. There is therefore a need to develop and license appropriate medical countermeasures against this virus. To determine whether the common marmoset (Callithrix jacchus) would be an appropriate model to assess vaccines or therapies against EBOV disease (EVD), initial susceptibility, lethality and pathogenesis studies were performed. Low doses of EBOV-Kikwit, between 4 and 27 times the 50% tissue culture infectious dose, were sufficient to cause a lethal, reproducible infection. Animals became febrile between days 5 and 6, maintaining a high fever before succumbing to EVD between 6 and 8 days after challenge. Typical signs of EVD were observed. Pathogenesis studies revealed that virus was isolated from the lungs of animals beginning on day 3 after challenge and from the liver, spleen and blood beginning on day 5. The most striking features were observed in animals that succumbed to infection, including high viral titers in all organs, increased levels of liver function enzymes and blood clotting times, decreased levels of platelets, multifocal moderate to severe hepatitis, and perivascular edema., (© Crown copyright 2015.)

Vascular access for catheterization of a pediatric patient on extracorporeal membrane oxygenation (ECMO) was facilitated by adding an accessory limb to the ECMO circuit. This limb was terminated with a hemostatic valve allowing insertion of a catheter. Changes in support parameters compensated for the change in the effective diameter of the ECMO cannula on insertion of the catheter. This method can overcome difficulties in obtaining vascular access for patients on ECMO., (© The Author(s) 2014.)

Marburg virus causes a highly infectious and lethal haemorrhagic fever in primates and may be exploited as a potential biothreat pathogen. To combat the infection and threat of Marburg haemorrhagic fever, there is a need to develop and license appropriate medical countermeasures. To determine whether the common marmoset (Callithrix jacchus) would be an appropriate model to assess therapies against Marburg haemorrhagic fever, initial susceptibility, lethality and pathogenesis studies were performed. Low doses of virus, between 4 and 28 TCID50 , were sufficient to cause a lethal, reproducible infection. Animals became febrile between days 5 and 6, maintaining a high fever before succumbing to disease between 8 and 11 days postchallenge. Typical signs of Marburg virus infection were observed including haemorrhaging and a transient rash. In pathogenesis studies, virus was isolated from the animals' lungs from day 3 postchallenge and from the liver, spleen and blood from day 5 postchallenge. Early signs of histopathology were apparent in the kidney and liver from day 3. The most striking features were observed in animals exhibiting severe clinical signs, which included high viral titres in all organs, with the highest levels in the blood, increased levels in liver function enzymes and blood clotting times, decreased levels in platelets, multifocal moderate-to-severe hepatitis and perivascular oedema., (© 2013 Crown copyright. International Journal of Experimental Pathology © 2013 International Journal of Experimental Pathology.)

Objective: To analyze safety and efficiency of a subcutaneous figure of eight suture for hemostasis after large caliber venous sheath access in children., Background: Vascular complications remain a significant cause of morbidity after pediatric cardiac catheterization. In an attempt to reduce such complications and yet improve lab efficiency and decrease length of stay, various techniques have been applied to improve time to hemostasis., Methods: Prospectively recorded were vascular complications and hemostasis times in children where hemostasis was attempted using a figure of eight subcutaneous suture following large caliber venous cannulation. These were compared to a matched group achieving hemostasis using standard manual pressure techniques. Vascular ultrasound assessments were performed within 24 hr of hemostasis in both groups., Results: Thirty-two subcutaneous sutures were placed in 26 children, mean weights 31.9 kg [median (range): 29.4 (8.4 to 96) kg], with a mean sheath French size of 9.2 [8; (6 to 22)], 11 >10 French, compared to 33 sheaths in 30 cases using manual compression, mean sheath French size 9.1 (9; (6 to 13), with 10 cases ≥10 French. The mean and median times to hemostasis were shorter in the suture group: 13.6 min (P < 0.05) and 10 min (P < 0.05), respectively. Vascular complication rate was also lower in the suture group (n = 0) compared with the control group (n = 2) but did not achieve statistical significance., Conclusions: A subcutaneous figure of eight suture hemostasis strategy can provide a safe and efficient method for large caliber venous hemostasis in a pediatric practice with improved hemostasis times and no additional morbidity., (Copyright © 2012 Wiley Periodicals, Inc.)

Normal immunocompetent mice are not susceptible to non-adapted filoviruses. There are therefore two strategies available to establish a murine model of filovirus infection: adaptation of the virus to the host or the use of genetically modified mice that are susceptible to the virus. A number of knockout (KO) strains of mice with defects in either their adaptive or innate immunity are susceptible to non-adapted filoviruses. In this study, A129 α/β -/- interferon receptor-deficient KO mice, strain A129 IFN-α/β -/-, were used to determine the lethality of a range of filoviruses, including Lake Victoria marburgvirus (MARV), Zaire ebolavirus (ZEBOV), Sudan ebolavirus (SEBOV), Reston ebolavirus (REBOV) and Côte d'Ivoire ebolavirus (CIEBOV), administered by using intraperitoneal (IP) or aerosol routes of infection. One hundred percent mortality was observed in all groups of KO mice that were administered with a range of challenge doses of MARV and ZEBOV by either IP or aerosol routes. Mean time to death for both routes was dose-dependent and ranged from 5.4 to 7.4 days in the IP injection challenge, and from 10.2 to 13 days in the aerosol challenge. The lethal dose (50 % tissue culture infective dose, TCID(50)) of ZEBOV for KO mice was <1 TCID(50) ml(-1) when administered by either the IP or aerosol route of infection; for MARV the lethal dose was <1 TCID(50) ml(-1) by the IP route of infection and <10 TCID(50) ml(-1) by the aerosol route. In contrast, there was no mortality after infection with SEBOV or REBOV by either IP or aerosol routes of infection; all the mice lost weight (~15 % loss of group mean body weight with SEBOV and ~7 % with REBOV) but recovered to their original weights by day 14 post-challenge. There was no mortality in mice administered with CIEBOV via the IP route of infection and no clinical signs of infection were observed. The progression of disease was faster following infection with ZEBOV than with MARV but ultimately both viruses caused widespread infection with high titres of the infectious viruses in multiple organs. Histopathological observations were consistent with other animal models and showed widespread organ damage. This study suggests that MARV and ZEBOV are more virulent when administered via the IP route rather than by aerosol infection, although both are highly virulent by either route. The KO mouse may provide a useful model to test potential antiviral therapeutics against wild-type filoviruses.

Deposition of Bacillus anthracis endospores within either the lungs or nasal passages of A/J mice after aerosol exposure was influenced by different particle sized aerosols and resulted in different infection kinetics. The infection resulting from the inhalation of endospores within a 12 μm particle aerosol was prolonged compared to that from a 1 μm particle aerosol with a mean time-to-death of 161 ± 16.1 h and 101.6 ± 10.4 h, respectively. Inhalation of endospores within 1 μm or 12 μm particle aerosols resulted in a median lethal dose of 2432 and 7656 c.f.u., respectively. Initial involvement of the upper respiratory tract lymph nodes was observed in 75-83% of mice exposed to either the 1 μm or 12 μm particle inhalational infections. Lung deposition was significantly greater after inhalation of the 1 μm particle aerosol with pronounced involvement of the mediastinal lymph node. Gastrointestinal involvement was observed only in mice exposed to 12 μm particle aerosols where bacteriological and histopathological analysis indicated primary gastritis (17%), activation of the Peyer's patches (72%) and colonization and necrosis of the mesenteric lymph nodes (67%). Terminal disease was characterized by bacteraemia in both inhalational infections with preferential dissemination to spleen, liver, kidneys and thymus. Immunization with 1 μg recombinant protective antigen vaccine was equally efficacious against B. anthracis infections arising from the inhalation of 1 and 12 μm particle aerosols, providing 73-80% survival under a suboptimum immunization schedule.

There are no widely available vaccines or antiviral drugs capable of protecting against infection with Venezuelan equine encephalitis virus (VEEV), although an adenovirus vector expressing VEEV structural proteins protects mice from challenge with VEEV and is potentially a vaccine suitable for human use. This work examines whether alpha interferon (IFN-alpha) could act as an adjuvant for the adenovirus-based vaccine. IFN-alpha was either expressed by a plasmid linked to the adenovirus vaccine or encoded by a separate adenovirus vector administered as a mixture with the vaccine. In contrast to previous reports with other vaccines, the presence of IFN-alpha reduced the antibody response to VEEV. When IFN-alpha was encoded by adenovirus, the lack of a VEEV-specific response was accompanied by an increase in the immune response to the adenovirus vector. IFN-alpha also plays a direct role in defence against virus infection, inducing the expression of a large number of antiviral proteins. Adenovirus-delivered IFN-alpha protected mice from VEEV disease when administered 24 h prior to challenge, but not when administered 6 h post-challenge, suggesting that up to 24 h is required for the development of the IFN-mediated antiviral response.

CpG-DNA has been described as a potent activator of the innate immune system, with potential to protect against infection caused by a range of pathogens in a non-specific manner. Here two classes of CpG-DNA (CpG-A and CpG-B) have been investigated for their abilities to protect mice from infection with an orthopoxvirus (vaccinia virus). Dosing with either CpG-A or B by the intraperitonal or intranasal route protected mice against a subsequent intranasal challenge with vaccinia virus. To our knowledge, this is the first time CpG-mediated protection has been demonstrated at the lung surface. The level of protection was greater when CpG-DNA was administered intranasally demonstrating a clear relationship between the route of CpG dosing and infection route. Treatment with CpG-B reduced viral titer in the lung by 10,000-fold at day 3 post-infection. The CC chemokines RANTES and MIP-1beta were elevated in the broncho-alveolar lavage from animals treated intranasally with CpG-B compared to untreated and intraperitoneally dosed controls, and it is possible that these chemokines play a role in the clearance of intranasally delivered vaccinia virus.