A Quality Improvement Project on Pain Management at a Tertiary Pediatric Hospital.

To assess and improve pain management practices for hospitalized children in an urban tertiary pediatric teaching hospital. METHODS: Health Quality Ontario Quality Improvement (QI) framework informed this study. A pre (T1) - post (T2) intervention assessment included chart reviews and children/caregiver surveys to ascertain pain management practices. Information on self-reported pain intensity, painful procedures, pain treatment and satisfaction were obtained from children/caregivers. Documented pain assessment, pain scores, and pharmacological/non-pharmacological pain treatments were collected by chart review. T1 data was fed back to pediatric units to inform their decisions and pain management targets. RESULTS: At T1, 51 (58% of eligible participants) children/caregivers participated. At T2, 86 (97%) chart reviews and 51 (54%) children/caregivers surveys were completed. Most children/caregivers at T1 (78%) and T2 (80%) reported moderate to severe pain during their hospitalization. A mean of 2.6 painful procedures were documented in the previous 24 h, with the most common being needle-related procedures at both T1 and T2. Pain management strategies were infrequently used during needle-related procedures at both time points. CONCLUSION: No improvements in pain management as measured by the T1 and T2 data occurred. Findings informed further pain management initiatives in the participating hospital.

Comparison of two measures of behavior change in children after day surgery.

BACKGROUND: A contemporary, well-validated instrument for the measurement of behavior change in children after general anesthesia is lacking. The Post Hospitalization Behavior Questionnaire for Ambulatory Surgery (PHBQ-AS) has been developed as an updated version of the original Post Hospitalization Behavior Questionnaire (PHBQ) to better reflect the current patient population and modern anesthetic practices. AIMS: To assess the reliability of the PHBQ-AS and determine concurrent validity with another measure of child behavior, the Strength and Difficulties Questionnaire (SDQ). METHODS: We compared the PHBQ-AS with the SDQ in 248 children presenting for day-case surgery. A baseline SDQ measurement was taken prior to surgery, and then, both scales were administered on days 3, 14, and 28 postsurgery. RESULTS: The PHBQ-AS demonstrated good reliability in terms of internal consistency with a Cronbach's alpha of 0.79 and split-half correlation with Spearman Brown adjustment of 0.85. There was weak correlation with the SDQ on day 3 postoperatively (Pearson's r = 0.201), moderate correlation on day 14 (Pearson's r = 0.421), and weak-to-moderate correlation on day 28 (Pearson's r = 0.340). A cut-off score of 3.2 on the PHBQ-AS for the diagnosis of negative behavior demonstrated equivalence with the SDQ results; however, the SDQ results remained relatively constant throughout the study period and reflected the expected rate of increased risk of problem behavior in children. CONCLUSIONS: The PHBQ-AS showed good reliability but only had weak-to-moderate correlation with another measure of child behavior, the SDQ. Further validation is required before the PHBQ-AS is used for the routine measurement of behavior change in children after anesthesia, or alternatively, a new instrument needs to be developed in order for research to advance in this area.

Long-Term Functional Outcomes After Sepsis for Adult and Pediatric Critical Care Patients-Protocol for a Systematic Review.

Objective: Sepsis is responsible for a massive burden of disease, with a global estimate of 48.9 million cases resulting in approximately 11 million deaths annually. Survivors of sepsis may also experience long-term impairments that can persist for years after hospital discharge. These cognitive, physical and/or psychosocial deficits may contribute to a lower health related quality of life and represent a significant ongoing burden to the individual, the community and the health care system. We aim to systematically review the available evidence on long-term functional and quality of life outcomes after sepsis in children and adults. Data Sources: Medline, EMBASE, and CINAHL will be searched for eligible studies. Study Selection: Studies of adult and pediatric survivors of sepsis who had required admission to intensive care will be included. A minimum 6 month prospective follow up will be required. Accepted outcomes will be any validated measure of health-related quality of life (HRQoL) or functional deficits, using the Post-Intensive Care Syndrome (PICS) framework of cognitive, physical or psychosocial outcomes. Data Extraction: Data extraction will include information related to study characteristics, population characteristics, clinical criteria and outcomes. Data Synthesis: Studies meeting the inclusion criteria will be presented descriptively separated for pediatric and adult age groups. Meta-analysis will be attempted if sufficient primary data from several studies applying the same tests and outcomes are available. The primary outcome is HRQoL after sepsis; secondary outcomes include the functional status at follow-up. Conclusions: This systematic review will define the long-term impact of sepsis survivorship. The data will contribute to informing patient, clinician and stakeholder decisions and guide further research and resource management.

Be Sweet to Hospitalized Toddlers During Venipuncture: A Randomized Controlled Trial of Sucrose Compared With Water.

OBJECTIVES: High-quality evidence demonstrates analgesic effects of sweet-tasting solutions for infants during painful procedures. However, evidence of the analgesic effects of sucrose beyond 12 months of age is less certain. The aim of this study was to ascertain the efficacy of oral sucrose in hospitalized toddlers (ages 12 to 36 mo) compared with placebo (water) during venipuncture. MATERIALS AND METHODS: Blinded, 2-armed randomized controlled trial including hospitalized toddlers aged 12 to 36 months. Toddlers were randomized to either 25% sucrose or water before venipuncture, stratified by age (12 to 24 mo and more than 24 to 36 mo). Standard of care included topical anesthetics for both groups. Pain assessment included cry duration and FLACC (Face, Legs, Activity, Cry, Consolability) scores. Descriptive statistics and linear models were used to report the percentage of time crying and mean differences in FLACC scores. Data analysis was performed using R, version 3.6.3. RESULTS: A total of 95 toddlers were randomized and 85 subsequently studied. The median percentage of time spent crying between insertion of the first needle and 30 seconds after the end of procedure in both groups was 81% (interquartile range=66%). There was no significant difference in crying time and FLACC scores between groups (P>0.05). When examining effects of sucrose for the younger toddlers (less than 24 mo of age) there was a reduction in crying time of 10% and a 1.2-point reduction in mean FLACC scores compared with the toddlers older than 24 months. DISCUSSION: Findings highlight that toddlers become highly distressed during venipuncture, despite the standard care of topical anesthetics. In addition, sucrose does not effectively reduce distress especially in the older group of toddlers.

An observational study of hypoactive delirium in the post-anesthesia recovery unit of a pediatric hospital.

BACKGROUND: Hypoactive delirium is present when an awake child is unaware of his or her surroundings, is unable to focus attention, and appears quiet and withdrawn. This condition has been well-described in the intensive care setting but has not been extensively studied in the immediate post-anesthetic period. AIM: To determine if hypoactive emergence delirium occurs in the recovery unit of a pediatric hospital, and if so, what proportion of emergence delirium is hypoactive in nature. METHODS: We conducted an observational study using the Cornell Assessment of Pediatric Delirium in a cohort of 4424 children recovered at a tertiary pediatric hospital. The incidence of emergence delirium detected using the Pediatric Anesthetic Emergence Delirium (PAED) scale was also recorded for comparison. RESULTS: There were 74 cases of emergence delirium detected during the study period using the Cornell Assessment of Pediatric Delirium (1.7%). Only 57 cases were detected using the Pediatric Anesthetic Emergence Delirium scale. The additional 17 cases detected using the Cornell Assessment of Pediatric Dlirium represent cases of hypoactive delirium. In this cohort of pediatric patients, 23% of all cases of emergence delirium were hypoactive in nature. CONCLUSION: The significance of hypoactive delirium in this population is unknown; however, previous studies have shown that emergence delirium can result in post-operative behavior changes and may affect compliance with future episodes of care. However, hypoactive delirium is often missed without active screening. The prevalence detected in this study therefore suggests hypoactive delirium warrants further investigation.

Cognitive/affective factors are associated with children's acute posttraumatic stress following pediatric intensive care.

This study aimed to explore children's experiences and memories of the pediatric intensive care unit (PICU) and identify the relative importance of premorbid, trauma, and cognitive/affective variables associated with acute posttraumatic stress symptoms (PTSS). Participants were 95 children aged 6-16 years admitted to the PICU and their parents. Children completed questionnaires and an interview assessing PTSS, peritrauma affect, and their memory of the admission 3 weeks following discharge. Medical data were extracted from patient charts. Premorbid and demographic data were provided by parent questionnaire. Most children remembered some aspects of their admission. Younger age, admission for traumatic injury (rather than non-injury-related reasons), and cognitive/affective factors including confusion, peritrauma panic, and sensory memory quality were associated with acute PTSS. Age and traumatic injury accounted for 18% of the variance in PTSS (p < .01). The addition of cognitive/affective variables increased the explained variance to 38% (p < .001). Child age did not moderate the effect of cognitive/affective variables on PTSS. This study demonstrates that objective indicators of disease severity do not adequately explain the high prevalence of PTSS in children following PICU admission. It also suggests that subjective, cognitive factors such as the way children process and remember a PICU admission are very important in the onset of PTSS. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

A trivalent gC2/gD2/gE2 vaccine for herpes simplex virus generates antibody responses that block immune evasion domains on gC2 better than natural infection.

Vaccines for prevention and treatment of genital herpes are high public health priorities. Our approach towards vaccine development is to focus on blocking virus entry mediated by herpes simplex virus type 2 (HSV-2) glycoprotein D (gD2) and to prevent the virus from evading complement and antibody attack by blocking the immune evasion domains on HSV-2 glycoproteins C (gC2) and E (gE2), respectively. HSV-2 gC2 and gE2 are expressed on the virion envelope and infected cell surface where they are potential targets of antibodies that bind and block their immune evasion activities. We demonstrate that antibodies produced during natural infection in humans or intravaginal inoculation in guinea pigs bind to gC2 but generally fail to block the immune evasion domains on this glycoprotein. In contrast, immunization of naïve or previously HSV-2-infected guinea pigs with gC2 subunit antigen administered with CpG and alum as adjuvants produces antibodies that block domains involved in immune evasion. These results indicate that immune evasion domains on gC2 are weak antigens during infection, yet when used as vaccine immunogens with adjuvants the antigens produce antibodies that block immune evasion domains.

Does dexmedetomidine given as a premedication or intraoperatively reduce post-hospitalisation behaviour change in children? A study protocol for a randomised controlled trial in a tertiary paediatric hospital.

INTRODUCTION: It has been reported that post-hospitalisation behaviour change (PHBC) occurs in over 50% of children undergoing a general anaesthetic and manifests as behaviours such as sleep and eating disorders, defiance of authority, nightmares, enuresis and temper tantrums. The effect is usually short-lived (2-4 weeks); however, in 5-10% of children, these behaviours can last up to 12 months. The risk factors for developing PHBC include underlying anxiety in the child or parent, a previous bad hospital experience, emergence delirium and preschool age. A recent meta-analysis of alpha-2 agonists (including dexmedetomidine) found that they effectively reduce the incidence of emergence delirium but none of the studies looked at longer term outcomes, such as PHBC. METHODS AND ANALYSIS: Two-year-old to seven-year-old children requiring general anaesthesia for common day-case procedures will be randomly assigned to one of three groups: a dexmedetomidine pre medication group, an intraoperative dexmedetomidine group and a control group. Baseline anxiety levels of the parent will be recorded and the anxiety of the child during induction of anaesthesia will also be recorded using validated tools. The primary outcome will be negative behaviours after hospitalisation and these will be measured using the Post Hospitalisation Behaviour Questionnaire for Ambulatory Surgery and the Strengths and Difficulties Questionnaire. These questionnaires will be administered by a blinded researcher at days 3, 14 and 28 post surgery. ETHICS AND DISSEMINATION: Ethics approval has been granted by the Children's Health Queensland human research ethics committee (HREC/15/QRCH/248) and the University of Queensland human research ethics office (#2016001715). Any amendments to this protocol will be submitted to the ethics committees for approval. TRIAL REGISTRATION NUMBER: ANZCTR:12616000096459; Pre-results.

Severe viral respiratory infections in children with IFIH1 loss-of-function mutations.

Viral respiratory infections are usually mild and self-limiting; still they exceptionally result in life-threatening infections in previously healthy children. To investigate a potential genetic cause, we recruited 120 previously healthy children requiring support in intensive care because of a severe illness caused by a respiratory virus. Using exome and transcriptome sequencing, we identified and characterized three rare loss-of-function variants in IFIH1, which encodes an RIG-I-like receptor involved in the sensing of viral RNA. Functional testing of the variants IFIH1 alleles demonstrated that the resulting proteins are unable to induce IFN-ß, are intrinsically less stable than wild-type IFIH1, and lack ATPase activity. In vitro assays showed that IFIH1 effectively restricts replication of human respiratory syncytial virus and rhinoviruses. We conclude that IFIH1 deficiency causes a primary immunodeficiency manifested in extreme susceptibility to common respiratory RNA viruses.

Immune responses elicited by the GEN-003 candidate HSV-2 therapeutic vaccine in a randomized controlled dose-ranging phase 1/2a trial.

PURPOSE: GEN-003 is a candidate therapeutic HSV-2 vaccine containing a fragment of infected cell protein 4 (ICP4.2), a deletion mutant of glycoprotein D2 (gD2ΔTMR), and Matrix-M2 adjuvant. In a dose-ranging phase 1/2a clinical trial, immunization with GEN-003 reduced viral shedding and the percentage of reported herpetic lesion days. Here we examine the immune responses in the same trial, to characterize vaccine-related changes in antibody and cell-mediated immunity. METHODS: Participants with genital HSV-2 infection were randomized to 1 of 3 doses of GEN-003, antigens without adjuvant, or placebo. Subjects received 3 intramuscular doses, three weeks apart, and were monitored for viral shedding, lesions and immunogenicity. Antibody titers were measured by ELISA and neutralization assay in serum samples collected at baseline and 3weeks post each dose. T cell responses were assessed pre-immunization and 1week post each dose by IFN-γ ELISpot and intracellular cytokine staining. Blood was also collected at 6 and 12months to monitor durability of immune responses. RESULTS: Antibody and T cell responses increased with vaccination and were potentiated by adjuvant. Among the doses tested, the rank order of reduction in viral shedding follows the ranking of fold change from baseline in T cell responses. Some immune responses persisted up to 12months. CONCLUSION: All measures of immunity are increased by vaccination with GEN-003; however, a correlate of protection is yet to be defined.

Development of a high-throughput ß-Gal-based neutralization assay for quantitation of herpes simplex virus-neutralizing antibodies in human samples.

Measurement of neutralizing antibodies against herpes simplex virus (HSV) is important for evaluation of candidate vaccines. The established plaque-reduction neutralization assay is time consuming, labor intensive, and difficult to validate and transfer. Here, we describe the characterization of a HSV-neutralization assay based on the expression of a reporter gene, ß-galactosidase (ß-Gal). Using previously constructed HSV-ß-Gal recombinant viruses, HSV-2/Gal and HSV-1/tk12, we developed a colorimetric ß-Gal-based neutralization assay that is sensitive and highly reproducible, and performed in less than 48h. HSV-1 and HSV-2 neutralizing titers measured by the ß-Gal-based neutralization assay were equivalent to those obtained by a plaque reduction neutralization assay. Intra- and inter-assay precision studies demonstrated that the ß-Gal-based assay was repeatable and yielded low and acceptable variation. In addition, comparison of HSV-2 neutralizing antibody (NAb) titers measured in two independent laboratories by two unique ß-Gal-based assays showed a highly significant correlation (r=0.9499, p<0.0001) between the two assays. The new assay will serve as an important tool both for preclinical and clinical trials of new HSV vaccines.

A comparison of the performance of the Braden Q and the Glamorgan paediatric pressure ulcer risk assessment scales in general and intensive care paediatric and neonatal units.

AIMS: To compare the predictive ability of two risk assessment scales used in children. BACKGROUND: There are several risk assessment scales (RASs) employed in paediatric settings but most have been modified from adult scales such as the Braden Q whereas the Glamorgan was an example of a scale designed for children. METHODS: Using incidence data from 513 paediatric hospital admissions, receiver operating characteristic (ROC) was employed to compare the two scales. The area under the curve (AUC) was the outcome of interest. RESULTS: The two scales were similar in this population in terms of area under the curve. Neonatal and paediatric intensive care were similar in terms of AUC for both scales but in general paediatric wards the Braden Q may be superior in predicting risk. CONCLUSION: Either scale could be used if the predictive ability was the outcome of interest. The scales appear to work well with neonatal, paediatric intensive care and general children's wards. However the Glamorgan scale is probably preferred by childrens' nurses as it is easy to use and designed for use in children. There is some suggestion that while the two scales are similar in intensive care, for general paediatrics the Braden Q may be the better scale.

'True Blood' The Critical Care Story: An audit of blood sampling practice across three adult, paediatric and neonatal intensive care settings.

BACKGROUND: Anaemia is common in critically ill patients, and has a significant negative impact on patients' recovery. Blood conservation strategies have been developed to reduce the incidence of iatrogenic anaemic caused by sampling for diagnostic testing. OBJECTIVES: Describe practice and local guidelines in adult, paediatric and neonatal Australian intensive care units (ICUs) regarding blood sampling and conservation strategies. METHODS: Cross-sectional descriptive study, conducted July 2013 over one week in single adult, paediatric and neonatal ICUs in Brisbane. Data were collected on diagnostic blood samples obtained during the study period, including demographic and acuity data of patients. Institutional blood conservation practice and guidelines were compared against seven evidence-based recommendations. RESULTS: A total of 940 blood sampling episodes from 96 patients were examined across three sites. Arterial blood gas was the predominant reason for blood sampling in each unit, accounting for 82% of adult, 80% of paediatric and 47% of neonatal samples taken (p<0.001). Adult patients had significantly more median [IQR] samples per day in comparison to paediatrics and neonates (adults 5.0 [2.4]; paediatrics 2.3 [2.9]; neonatal 0.7 [2.7]), which significantly increased median [IQR] blood sampling costs per day (adults AUD$101.11 [54.71]; paediatrics AUD$41.55 [56.74]; neonatal AUD$8.13 [14.95]; p<0.001). The total volume of samples per day (median [IQR]) was also highest in adults (adults 22.3mL [16.8]; paediatrics 5.0mL [1.0]; neonates 0.16mL [0.4]). There was little information about blood conservation strategies in the local clinical practice guidelines, with the adult and neonatal sites including none of the seven recommendations. CONCLUSIONS: There was significant variation in blood sampling practice and conservation strategies between critical care settings. This has implications not only for anaemia but also infection control and healthcare costs.

Identification of novel virus-specific antigens by CD4⁺ and CD8⁺ T cells from asymptomatic HSV-2 seropositive and seronegative donors.

Reactivation of latent herpes simplex virus 2 (HSV-2) infections can be characterized by episodic recurrent genital lesions and/or viral shedding. We hypothesize that infected (HSV-2(pos)) asymptomatic individuals have acquired T cell responses to specific HSV-2 antigen(s) that may be an important factor in controlling their recurrent disease symptoms. Our proteomic screening technology, ATLAS, was used to characterize the antigenic repertoire of T cell responses in infected (HSV-2(pos)) and virus-exposed seronegative (HSV-2(neg)) subjects. T cell responses, determined by IFN-γ secretion, were generated to gL, UL2, UL11, UL21, ICP4, ICP0, ICP47 and UL40 with greater magnitude and/or frequency among cohorts of exposed HSV-2(neg) or asymptomatic HSV-2(pos) individuals, compared to symptomatic recurrent HSV-2(pos) subjects. T cell antigens recognized preferentially among individuals who are resistant to infection or who are infected and have mild or no clinical disease may provide new targets for the design of vaccines aimed at treating and/or preventing HSV-2 infection.

The diagnosis of posttraumatic stress disorder in school-aged children and adolescents following pediatric intensive care unit admission.

OBJECTIVES: This study explored the diagnosis of posttraumatic stress disorder (PTSD) in children and adolescents following pediatric intensive care unit (PICU) admission. Specifically, the study aimed to describe the presentation and prevalence of PTSD symptoms 6 months postdischarge, explore the validity of the DSM-IV PTSD algorithm and alternative PTSD algorithm (PTSD-AA) in school-aged children and adolescents, and examine the diagnostic utility of Criterion C3 (inability to recall aspects of a trauma) in this cohort. METHODS: Participants were 59 children aged 6-16, admitted to PICU for at least 8 hours. PTSD was assessed via diagnostic interview (Children's PTSD Inventory) 6 months following PICU discharge. RESULTS: The PTSD-AA was found to provide the most valid measure of PTSD at 6 months. Removing Criterion C3 improved the validity of Criterion C. CONCLUSIONS: This study supports the use of the PTSD-AA excluding Criterion C3 for identifying highly traumatized children and adolescents following PICU admission.

An adjuvanted herpes simplex virus 2 subunit vaccine elicits a T cell response in mice and is an effective therapeutic vaccine in Guinea pigs.

Immunotherapeutic herpes simplex virus 2 (HSV-2) vaccine efficacy depends upon the promotion of antigen-specific immune responses that inhibit reactivation or reactivated virus, thus controlling both recurrent lesions and viral shedding. In the present study, a candidate subunit vaccine, GEN-003/MM-2, was evaluated for its ability to induce a broad-spectrum immune response in mice and therapeutic efficacy in HSV-2-infected guinea pigs. GEN-003 is comprised of HSV-2 glycoprotein D2 (gD2ΔTMR340-363) and a truncated form of infected cell polypeptide 4 (ICP4383-766), formulated with Matrix M-2 (MM-2) adjuvant (GEN-003/MM-2). In addition to eliciting humoral immune responses, CD4(+) and CD8(+) T cells characterized by the secretion of multiple cytokines and cytolytic antigen-specific T cell responses that were able to be recalled at least 44 days after the last immunization were induced in immunized mice. Furthermore, vaccination with either GEN-003 or GEN-003/MM-2 led to significant reductions in both the prevalence and severity of lesions in HSV-2-infected guinea pigs compared to those of phosphate-buffered saline (PBS) control-vaccinated animals. While vaccination with MM-2 adjuvant alone decreased recurrent disease symptoms compared to the PBS control group, the difference was not statistically significant. Importantly, the frequency of recurrent viral shedding was considerably reduced in GEN-003/MM-2-vaccinated animals but not in GEN-003- or MM-2-vaccinated animals. These findings suggest a possible role for immunotherapeutic GEN-003/MM-2 vaccination as a viable alternative to chronic antiviral drugs in the treatment and control of genital herpes disease.

The utility of the Children's Revised Impact of Event Scale in screening for concurrent PTSD following admission to intensive care.

Although there is some information available regarding the utility of the Children's Revised Impact of Event Scale (CRIES) in screening for posttraumatic stress disorder (PTSD), data are scarce and limited to studies sampling children predominantly injured in road traffic accidents. This study investigated the utility of 2 versions, the CRIES-8 and CRIES-13, in identifying those children meeting criteria for PTSD following admission to a pediatric intensive care unit (PICU). The Children's PTSD Inventory (CPTSDI), a diagnostic interview, and the CRIES-13 were administered to 55 children, aged 6-16 years, 6 months following admission to the PICU. Of the 55, 14 (25%) met criteria on the CPTSDI. Cutoff scores of 14.5 on the CRIES-8 and 22.5 on the CRIES-13 maximized sensitivity and specificity and correctly classified 78%-86% of children. Both cutoff scores were lower than those reported in other samples. The CRIES-13 appeared to offer greater utility than the CRIES-8, also in contrast to previous findings. Methodological or sampling differences may account for the discrepancy with prior studies. The proposed cutoffs are recommended specifically for use with PICU patients and replication and further validation of the CRIES with other samples is warranted.

Alphavirus replicon particles encoding the fusion or attachment glycoproteins of respiratory syncytial virus elicit protective immune responses in BALB/c mice and functional serum antibodies in rhesus macaques.

Respiratory syncytial virus (RSV) is a major cause of acute respiratory tract disease in humans. Towards development of a prophylactic vaccine, we genetically engineered Venezuelan equine encephalitis virus (VEEV) replicons encoding the fusion (Fa) or attachment (Ga or Gb) proteins of the A or B subgroups of RSV. Intramuscular immunization with a formulation composed of equal amounts of each replicon particle (3vRSV replicon vaccine) generated serum neutralizing antibodies against A and B strains of RSV in BALB/c mice and rhesus macaques. When contrasted with purified natural protein or formalin-inactivated RSV formulated with alum, the 3vRSV replicon vaccine induced balanced Th1/Th2 T cell responses in mice. This was evident in the increased number of RSV-specific IFN-gamma(+) splenocytes following F or G peptide stimulation, diminished quantity of eosinophils and type 2 T cell cytokines in the lungs after challenge, and increased in vivo lysis of RSV peptide-loaded target cells. The immune responses in mice were also protective against intranasal challenge with RSV. Thus, the replicon-based platform represents a promising new strategy for vaccines against RSV.

Evaluation of neurovirulence and biodistribution of Venezuelan equine encephalitis replicon particles expressing herpes simplex virus type 2 glycoprotein D.

The safety of a propagation-defective Venezuelan equine encephalitis virus (VEEV) replicon particle vaccine was examined in mice. After intracranial inoculation we observed approximately 5% body weight loss, modest inflammatory changes in the brain, genome replication, and foreign gene expression. These changes were transient and significantly less severe than those caused by TC-83, a live-attenuated vaccinal strain of VEEV that has been safely used to immunize military personnel and laboratory workers. Replicon particles injected intramuscularly or intravenously were detected at limited sites 3 days post-administration, and were undetectable by day 22. There was no evidence of dissemination to spinal cord or brain after systemic administration. These results demonstrate that propagation-defective VEEV replicon particles are minimally neurovirulent and lack neuroinvasive potential.