Palivizumab prophylaxis reduces hospitalization due to respiratory syncytial virus in young children with hemodynamically significant congenital heart disease

Innate Type 2 Responses to Respiratory Syncytial Virus Infection

Respiratory syncytial virus (RSV) is a common and contagious virus that results in acute respiratory tract infections in infants. In many cases, the symptoms of RSV remain mild, however, a subset of individuals develop severe RSV-associated bronchiolitis. As such, RSV is the chief cause of infant hospitalization within the United States. Typically, the immune response to RSV is a type 1 response that involves both the innate and adaptive immune systems. However, type 2 cytokines may also be produced as a result of infection of RSV and there is increasing evidence that children who develop severe RSV-associated bronchiolitis are at a greater risk of developing asthma later in life. This review summarizes the contribution of a newly described cell type, group 2 innate lymphoid cells (ILC2), and epithelial-derived alarmin proteins that activate ILC2, including IL-33, IL-25, thymic stromal lymphopoietin (TSLP), and high mobility group box 1 (HMGB1). ILC2 activation leads to the production of type 2 cytokines and the induction of a type 2 response during RSV infection. Intervening in this innate type 2 inflammatory pathway may have therapeutic implications for severe RSV-induced disease.

Infectious Diseases Society of America Guidelines on the Treatment and Management of Patients with COVID-19

BACKGROUND

There are many pharmacologic therapies that are being used or considered for treatment of COVID-19. There is a need for frequently updated practice guidelines on their use, based on critical evaluation of rapidly emerging literature.

OBJECTIVE

Develop evidence-based rapid guidelines intended to support patients, clinicians and other health-care professionals in their decisions about treatment and management of patients with COVID-19.

METHODS

IDSA formed a multidisciplinary guideline panel of infectious disease clinicians, pharmacists, and methodologists with varied areas of expertise. Process followed a rapid recommendation checklist. The panel prioritized questions and outcomes. Then a systematic review of the peer-reviewed and grey literature was conducted. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the certainty of evidence and make recommendations.

RESULTS

The IDSA guideline panel agreed on 7 treatment recommendations and provided narrative summaries of other treatments undergoing evaluations.

CONCLUSIONS

The panel expressed the overarching goal that patients be recruited into ongoing trials, which would provide much needed evidence on the efficacy and safety of various therapies for COVID-19, given that we could not make a determination whether the benefits outweigh harms for most treatments.

Neutralizing Monoclonal Antibodies against the Gn and the Gc of the Andes Virus Glycoprotein Spike Complex Protect from Virus Challenge in a Preclinical Hamster Model

Hantaviruses are the etiological agent of hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS). The latter is associated with case fatality rates ranging from 30% to 50%. HCPS cases are rare, with approximately 300 recorded annually in the Americas. Recently, an HCPS outbreak of unprecedented size has been occurring in and around Epuyén, in the southwestern Argentinian state of Chubut. Since November of 2018, at least 29 cases have been laboratory confirmed, and human-to-human transmission is suspected. Despite posing a significant threat to public health, no treatment or vaccine is available for hantaviral disease. Here, we describe an effort to identify, characterize, and develop neutralizing and protective antibodies against the glycoprotein complex (Gn and Gc) of Andes virus (ANDV), the causative agent of the Epuyén outbreak. Using murine hybridoma technology, we generated 19 distinct monoclonal antibodies (MAbs) against ANDV GnGc. When tested for neutralization against a recombinant vesicular stomatitis virus expressing the Andes glycoprotein (GP) (VSV-ANDV), 12 MAbs showed potent neutralization and 8 showed activity in an antibody-dependent cellular cytotoxicity reporter assay. Escape mutant analysis revealed that neutralizing MAbs targeted both the Gn and the Gc. Four MAbs that bound different epitopes were selected for preclinical studies and were found to be 100% protective against lethality in a Syrian hamster model of ANDV infection. These data suggest the existence of a wide array of neutralizing antibody epitopes on hantavirus GnGc with unique properties and mechanisms of action.IMPORTANCE Infections with New World hantaviruses are associated with high case fatality rates, and no specific vaccine or treatment options exist. Furthermore, the biology of the hantaviral GnGc complex, its antigenicity, and its fusion machinery are poorly understood. Protective monoclonal antibodies against GnGc have the potential to be developed into therapeutics against hantaviral disease and are also great tools to elucidate the biology of the glycoprotein complex.

Expert consensus on palivizumab use for respiratory syncytial virus in developed countries

Respiratory syncytial virus (RSV) infection is a leading cause of hospitalisation in early childhood and palivizumab is the only licensed intervention for prevention. Palivizumab guidelines should reflect the latest evidence, in addition to cost-effectiveness and healthcare budgetary considerations. RSV experts from Europe, Canada and Israel undertook a systematic review of the evidence over the last 5 years and developed recommendations regarding prophylaxis in industrialised countries. Almost 400 publications were reviewed. This group recommended palivizumab for: preterm infants (<29 and ≤31 weeks gestational age [wGA] and ≤9 and ≤6 months of age, respectively; high-risk 32-35wGA), former preterm children ≤24 months with chronic lung disease/bronchopulmonary dysplasia, children ≤24 months with significant congenital heart disease; and other high-risk populations, such as children ≤24 months with Down syndrome, pulmonary/neuromuscular disorders, immunocompromised, and cystic fibrosis. Up to 5 monthly doses should be administered over the RSV season. It is our impression that the adoption of these guidelines would help reduce the burden of RSV.

Contribution of Dendritic Cells in Protective Immunity against Respiratory Syncytial Virus Infection

Respiratory syncytial virus (RSV) is a major cause of severe respiratory disease in infants and the elderly. The socioeconomic burden of RSV infection is substantial because it leads to serious respiratory problems, subsequent hospitalization, and mortality. Despite its clinical significance, a safe and effective vaccine is not yet available to prevent RSV infection. Upon RSV infection, lung dendritic cells (DCs) detecting pathogens migrate to the lymph nodes and activate the adaptive immune response. Therefore, RSV has evolved various immunomodulatory strategies to inhibit DC function. Due to the capacity of RSV to modulate defense mechanisms in hosts, RSV infection results in inappropriate activation of immune responses resulting in immunopathology and frequent reinfection throughout life. This review discusses how DCs recognize invading RSV and induce adaptive immune responses, as well as the regulatory mechanisms mediated by RSV to disrupt DC functions and ultimately avoid host defenses.

Estimating the impact of multiple immunization products on medically-attended respiratory syncytial virus (RSV) infections in infants

BACKGROUND

Palivizumab, a monoclonal antibody and the only licensed immunization product for preventing respiratory syncytial virus (RSV) infection, is recommended for children with certain high-risk conditions. Other antibody products and maternal vaccines targeting young infants are in clinical development. Few studies have compared products closest to potential licensure and have primarily focused on the effects on hospitalizations only. Estimates of the impact of these products on medically-attended (MA) infections in a variety of healthcare settings are needed to assist with developing RSV immunization recommendations.

METHODS

We developed a tool for practicing public health officials to estimate the impact of immunization strategies on RSV-associated MA lower respiratory tract infections (LRTIs) in various healthcare settings among infants <12 months. Users input RSV burden and seasonality and examine the influence of altering product efficacy and uptake assumptions. We used the tool to evaluate candidate products' impacts among a US birth cohort.

RESULTS

We estimated without immunization, 407,360 (range: 339,650-475,980) LRTIs are attended annually in outpatient clinics, 147,240 (126,070-168,510) in emergency departments (EDs), and 33,180 (24,760-42,900) in hospitals. A passive antibody candidate targeting all infants prevented the most LRTIs: 196,470 (48% of visits without immunization) outpatient clinic visits (range: 163,810-229,650), 75,250 (51%) EDs visits (64,430-86,090), and 18,140 (55%) hospitalizations (13,770-23,160). A strategy combining maternal vaccine candidate and palivizumab prevented 58,210 (14% of visits without immunization) LRTIs in outpatient clinics (range: 48,520-67,970), 19,580 (13%) in EDs (16,760-22,400), and 8,190 (25%) hospitalizations (6,390-10,150).

CONCLUSIONS

Results underscore the potential for anticipated products to reduce serious RSV illness. Our tool (provided to readers) can be used by different jurisdictions and accept updated data. Results can aid economic evaluations and public health decision-making regarding RSV immunization products.

Cardiopulmonary Bypass and Infant Vaccination Titers

BACKGROUND

Infants with congenital heart disease remain vulnerable to potentially preventable pathogens. Although immunization can significantly reduce this risk, it is unknown how immunization status can be affected by cardiac surgery with cardiopulmonary bypass (CPB). The objective was to evaluate the effect of CPB on infant vaccination status after cardiac surgery.

METHODS

We conducted a prospective observational study of patients between 2 and 14 months of age who had received at least their first round of infant vaccinations and who required cardiac surgery with CPB. Antibody titers were measured before CPB and again the following morning. Demographic and surgical variables were assessed via regression methods for their effects on the change in titers.

RESULTS

Among the 98 patients followed, there was no demonstrated difference between the pre- and postoperative values in regard to diphtheria, tetanus, polio 1, polio 3, or Haemophilus influenzae titers. Bordetella (1.03 vs 0.84, P < .001), and hepatitis B (log 2.10 vs 1.89, P = .001) titers did reduce after CPB but did not fall below the immunized threshold. Changes in antibody titers were not associated with time between immunization and surgery, age or weight at surgery, blood products administered, number of previous doses, time on CPB, or heterotaxy diagnosis for most of the vaccines.

CONCLUSIONS

Infant vaccine antibody titers were minimally affected by CPB and not associated with any easily modifiable surgical variables. Although antibody titers are only 1 marker of immunity, deviation from the recommended vaccination schedule may be unnecessary for children requiring congenital heart surgery.

Successful Vaccines

Vaccines are considered one of the most important advances in modern medicine and have greatly improved our quality of life by reducing or eliminating many serious infectious diseases. Successful vaccines have been developed against many of the most common human pathogens, and this success has not been dependent upon any one specific class of vaccine since subunit vaccines, non-replicating whole-virus or whole-bacteria vaccines, and attenuated live vaccines have all been effective for particular vaccine targets. After completing the initial immunization series, one common aspect of successful vaccines is that they induce long-term protective immunity. In contrast, several partially successful vaccines appear to induce protection that is relatively short-lived and it is likely that long-term protective immunity will be critical for making effective vaccines against our most challenging diseases such as AIDS and malaria.

Palivizumab Prophylaxis among Infants at Increased Risk of Hospitalization due to Respiratory Syncytial Virus Infection in UAE: A Hospital-Based Study

Background

Respiratory syncytial virus (RSV) represents a significant public health burden and the leading cause of lower respiratory tract infections globally, and it is the major cause of hospitalization during the winter. We aimed to evaluate the effectiveness of palivizumab prophylaxis to reduce the hospitalization in children at high risk of RSV infection.

Methods

We performed a retrospective observational single-arm hospital-based study including five RSV seasons (September to March) from 2012 to 2017. We retrospectively included premature infants born at less than 35 weeks of gestation with chronic lungs disease or hemodynamic significant congenital heart disease for palivizumab prophylaxis against RSV infection according to the criteria presented.

Results

A total of 925 children were enrolled in the study over the five RSV seasons. Of them, 410 (44.3%) infants born at <32 weeks of gestation and 515 (55.6%) infants born at 32-35 weeks of gestation with mean (±SD) birth weight of 1104.8 ± 402.85 and 1842.5 ± 377.5, respectively. The compliance with the course of palivizumab was reported in 841 (90.9%) children. Of them, about 75 (8.9%) hospitalized children were reported, and 17 (2.02%) RSV positive children were detected. Hospitalization due to RSV infection was decreased from 9.23% in the 2012-2013 season to 0.67% in the 2016-2017 season.

Conclusion

This study demonstrated that palivizumab prophylaxis in children at high risk of developing RSV infection was effective in reducing the risk of hospitalization with a high compliance rate over the five RSV seasons.

Patient equity and respiratory syncytial virus Immunoprophylaxis

An analysis of benefit and cost is critical for independent advisory groups that provide evidence-based recommendations. In many countries, the role of RSV immunoprophylaxis for infants at increased risk of hospitalization is controversial because of limited benefit and high cost. The report by Ginsberg and co-workers provides evidence, that in Israel, despite the potential benefit of palivizumab prophylaxis in reducing a small number of RSV hospitalizations but no evidence of long-term benefit, the cost is difficult to justify. Ideally, a safe and effective RSV vaccine or more effective and less expensive monoclonal antibody soon will become available.

TEMPORAL TREND OF HOSPITALIZATIONS FOR ACUTE BRONCHIOLITIS IN INFANTS UNDER ONE YEAR OF AGE IN BRAZIL BETWEEN 2008 AND 2015

OBJECTIVE

To evaluate the trend of hospitalization for acute bronchiolitis in infants under one year of age, in the past eight years and after the implementation of the palivizumab immunization program in Brazil.

METHODS

The study is a retrospective analysis of data on infants younger than one year of age, who were hospitalized with acute bronchiolitis between 2008 and 2015 in Brazil. The Brazilian National Health System database was used. The rates of hospitalization in the pre-implementation (2008-2012) and post-implementation (2014-2015) periods of the palivizumab immunization program were evaluated. The total number of admissions in the same period was used as a comparison.

RESULTS

Between January 2008 and December 2015, 263,679 hospitalizations for bronchiolitis were recorded in infants younger than one year of age, 60% represented by boys. The incidence of hospitalization for bronchiolitis increased by 49% over this period (8.5 to 12.7 per 1,000 inhabitants per year). Between 2013 and 2014, the incidence rate of hospitalization for acute bronchiolitis decreased by 8% (12.5 to 11.5 per 1,000 inhabitants per year). However, in the second year of the program, hospitalization rate increased again by 10% (12.7 per 1,000 inhabitants per years).

CONCLUSIONS

Acute bronchiolitis presented increasing rates of hospitalization over the study period. Hospitalization incidence for acute bronchiolitis declined one year after the implementation of palivizumab but increased again in the second year of the program.

Effectiveness of Palivizumab against Respiratory Syncytial Virus: Cohort and Case Series Analysis

OBJECTIVE

To measure the real-world effectiveness of palivizumab immunoprophylaxis against respiratory syncytial virus (RSV)-confirmed infection before age 2 years in a population-cohort of high-risk infants.

STUDY DESIGN

Palivizumab is funded for high-risk infants in Western Australia. We used probabilistically linked administrative data encompassing RSV laboratory-confirmed infections, hospital admissions, and palivizumab dispensing records for a cohort of 24 329 high-risk infants admitted to neonatal intensive care units, born 2002-2013 with follow-up to 2015. We used a traditional cohort method with Cox proportional hazards regression and a self-controlled case series analysis to assess effectiveness of palivizumab in reducing RSV-confirmed infection by number of doses.

RESULTS

From the cohort of 24 329 infants, 271 (1.1%) received at least 1 dose of palivizumab and 1506 (6.2%) had at least 1 RSV-confirmed infection before age 2 years. Using the traditional cohort approach, we found no protective association of palivizumab receipt with RSV detection (adjusted hazard ratio = 0.99 [95% CI 0.5, 1.9] for 1 dose). However, using a self-controlled case series to eliminate confounding by indication, a protective association was seen with a 74% lower RSV incidence (relative incidence = 0.26; 95% CI 0.11, 0.67) following any dose of palivizumab compared with control (nonexposed) periods.

CONCLUSIONS

After accounting for confounding by indication through a self-controlled analysis, palivizumab appeared effective for reducing virologically confirmed RSV in this high-risk cohort.

A potent broadly neutralizing human RSV antibody targets conserved site IV of the fusion glycoprotein

Respiratory syncytial virus (RSV) infection is the leading cause of hospitalization and infant mortality under six months of age worldwide; therefore, the prevention of RSV infection in all infants represents a significant unmet medical need. Here we report the isolation of a potent and broadly neutralizing RSV monoclonal antibody derived from a human memory B-cell. This antibody, RB1, is equipotent on RSV A and B subtypes, potently neutralizes a diverse panel of clinical isolates in vitro and demonstrates in vivo protection. It binds to a highly conserved epitope in antigenic site IV of the RSV fusion glycoprotein. RB1 is the parental antibody to MK-1654 which is currently in clinical development for the prevention of RSV infection in infants.

Respiratory syncytial virus (RSV) is a leading cause of infant hospitalization. Here, the authors isolate a human monoclonal antibody that binds to a highly conserved epitope on the RSV fusion protein, neutralizes RSV A and B subtypes equipotently and is protective in the cotton rat model.

Respiratory Syncytial Virus: Spectrum of Clinical Manifestations and Complications in Children

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infection in infants and young children. Despite its substantial disease burden, no effective vaccine is available. Clinical manifestations of RSV encompass the spectrum of acute upper and lower respiratory tract infection. Hallmarks of the virus are its propensity to progress to lower respiratory disease and to cause disproportionate disease severity at extremes of ages. Acute RSV infection may be complicated by secondary bacterial infections and respiratory failure requiring mechanical ventilation and prolonged hospitalization. In the developed world, most RSV infections are self-limited; however, globally, RSV is a significant cause of mortality in children younger than age 5 years. Severe RSV infection in infancy has also been associated with the development of childhood asthma. Thus, the extensive disease burden of RSV and its attributable mortality portend the urgency of vaccine development targeted toward populations disproportionately affected by severe disease. [Pediatr Ann. 2019;48(9):e349-e353.].

Immunoglobulin treatment for hospitalised infants and young children with respiratory syncytial virus infection

BACKGROUND

Millions of children are hospitalised due to respiratory syncytial virus (RSV) infection every year. Treatment is supportive, and current therapies (e.g. inhaled bronchodilators, epinephrine, nebulised hypertonic saline, and corticosteroids) are ineffective or have limited effect. Respiratory syncytial virus immunoglobulin is sometimes used prophylactically to prevent hospital admission from RSV-related illness. It may be considered for the treatment of established severe RSV infection or for treatment in an immunocompromised host, although it is not licenced for this purpose. It is unclear whether immunoglobulins improve outcomes when used as a treatment for established RSV infection in infants and young children admitted to hospital.  OBJECTIVES: To assess the effects of immunoglobulins for the treatment of RSV-proven lower respiratory tract infections in children aged up to three years, admitted to hospital.  SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Acute Respiratory Infections Group's Specialised Register, Ovid MEDLINE, Embase, CINAHL, and Web of Science (from inception to 6 November 2018) with no restrictions. We searched two trial registries for ongoing trials (to 30 March 2018) and checked the reference lists of reviews and included articles for additional studies.

SELECTION CRITERIA

Randomised controlled trials comparing immunoglobulins with placebo in hospitalised infants and children aged up to three years with laboratory-diagnosed RSV lower respiratory tract infection.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed risk of bias, and extracted data. We assessed evidence quality using GRADE.

MAIN RESULTS

We included seven trials involving 486 infants and children aged up to three years. The immunoglobulin preparations used in these trials included anti-RSV immunoglobulin and the monoclonal antibody preparations palivizumab and motavizumab. We assessed the primary outcomes of mortality, length of hospital stay, and adverse events as providing low- or very low-certainty evidence due to risk of bias and imprecision. All trials were conducted at sites in high-income countries (USA, Chile, New Zealand, Australia), with two studies including a site in a middle-income country (Panama). Five of the seven studies were "supported" or "sponsored" by the trial drug manufacturers. We found no evidence of a difference between immunoglobulins and placebo for mortality (risk ratio (RR) 0.87, 95% confidence interval (CI) 0.14 to 5.27; 3 trials; 196 children; 4 deaths; 2 deaths amongst 98 children receiving immunoglobulins, and 2 deaths amongst 98 children receiving placebo. One additional death occurred in a fourth trial, however, the study group of the child was not known and the data were not included in the analysis; very low-certainty evidence), and length of hospitalisation (mean difference -0.70, 95% CI -1.83 to 0.42; 5 trials; 324 children; low-certainty evidence). There was no evidence of a difference between immunoglobulins and placebo in adverse events of any severity or seriousness (reported in five trials) or serious adverse events (four trials) (RR for any severity 1.18, 95% CI 0.78 to 1.78; 340 children; low-certainty evidence, and for serious adverse events 1.08, 95% CI 0.65 to 1.79; 238 children; low-certainty evidence).We found no evidence of a significant difference between immunoglobulins and placebo for any of our secondary outcomes. We identified one ongoing trial.

AUTHORS' CONCLUSIONS

We found insufficient evidence of a difference between immunoglobulins and placebo for any review outcomes. We assessed the evidence for the effects of immunoglobulins when used as a treatment for RSV lower respiratory tract infection in hospitalised infants and young children as of low or very low certainty due to risk of bias and imprecision. We are uncertain of the effects of immunoglobulins on these outcomes, and the true effect may be substantially different from the effects reported in this review. All trials were conducted in high-income countries, and data from populations in which the rate of death from RSV infection is higher are lacking.

Respiratory Syncytial Virus Prophylaxis in Neurologic and Muscular Disorders in the Canadian Respiratory Syncytial Virus Evaluation Study of Palivizumab

BACKGROUND

This study aimed to examine the risk of respiratory-related hospitalization in children with neurologic and muscular disorders (NMDs) who received respiratory syncytial virus (RSV) prophylaxis in the Canadian RSV Evaluation Study of Palivizumab.

METHODS

Canadian RSV Evaluation Study of Palivizumab is a prospective registry of children who received ≥1 palivizumab injection among 32 Canadian sites. Demographic data were collected at enrollment, and respiratory events were documented monthly. Cox proportional hazard analyses were conducted to compare respiratory illness-related hospitalization (RIH) and RSV-related hospitalization (RSVH) among children with NMD and those prophylaxed for standard indications (SI) and complex medical disorders.

RESULTS

Group differences were found in enrollment age and weight, birth weight, household crowding, neonatal stay and supplemental oxygen requirement (all P < 0.05). RIH and RSVH incidences were 19.2%, 3.3% (NMD, n = 605); 6.0%, 1.5% (SI, n = 20,335), 9.4%, 1.6% (complex medical disorders, n = 4063), respectively. Children with NMD had a higher risk of RIH (hazard ratio [HR]: 1.90; 95% confidence interval (CI): 1.41-2.56; P < 0.0005) than those with SI. RSVH risk was greater in children with NMD compared with both the SI (HR: 2.26; 95% CI: 1.38-3.72; P = 0.001) and complex medical disorders groups (HR: 2.74; 95% CI: 1.55-4.84; P = 0.001). Children with more severe infantile onset NMD had a higher risk of RIH than those with general hypotonic disorders (HR: 1.69; 95% CI: 1.06-2.68; P = 0.027) but not RSVH.

CONCLUSIONS

Children with NMD who received palivizumab had a higher risk of both RIH and RSVH. Our results imply that all children with NMD, regardless of disease severity, are at risk for respiratory-related illness and RSV infection.

Respiratory Syncytial Virus and Associations With Cardiovascular Disease in Adults

Respiratory syncytial virus (RSV) is historically known for causing respiratory illness in young children, but the appreciation of its impact on older adults is growing. Studies have shown that hospitalization for respiratory illness due to RSV is complicated by cardiovascular events in 14% to 22% of adult patients, including worsening congestive heart failure, acute coronary syndrome, and arrhythmias. Additionally, underlying cardiovascular disease is associated with hospitalization in 45% to 63% of adults with confirmed RSV. In summary, patients with cardiopulmonary disease have higher rates of health care utilization for RSV-related illness and worse outcomes. Patients with cardiovascular disease likely represent an important target population for the rapidly developing field of RSV vaccines.

Pediatric intensive care unit admission due to respiratory syncytial virus: Retrospective multicenter study

BACKGROUND

We investigated the characteristics and clinical outcomes of respiratory syncytial virus (RSV)-related pediatric intensive care unit (PICU) hospitalization and assessed the palivizumab (PZ) prophylaxis eligibility according to different guidelines from Korea, EU, and USA.

METHODS

In this multicenter study, children <18 years of age hospitalized in six PICU from different hospitals due to severe RSV infection between September 2008 and March 2013 were included. A retrospective chart review was performed.

RESULTS

A total of 92 patients were identified. The median length of PICU stay was 6 days (range, 1-154 days) and median PICU care cost was USD2,741 (range, USD556-98 243). Of 62 patients who were <2 years old at the beginning of the RSV season, 33 (53.2%) were high-risk patients for severe RSV infection. Hemodynamically significant congenital heart disease (22.6%) was the most common risk factor, followed by chronic lung disease (11.3%), neuromuscular disease or congenital abnormality of the airway (NMD/CAA) (11.3%), and prematurity (8.1%). The percentage of patients eligible for PZ prophylaxis ranged from 38.7% to 48.4% based on the guidelines, but only two (2.2%) received PZ ≤30 days prior to PICU admission. The median duration of mechanical ventilation was longer in children with NDM/CAA than in those without risk factors (26 days; range, 24-139 days vs 6 days, range, 2-68 days, P = 0.033). RSV-attributable mortality was 5.4%.

CONCLUSIONS

Children <2 years old with already well-known high risks represent a significant proportion of RSV-related PICU admissions. Increasing of the compliance for PZ prophylaxis practice among physicians is needed. Further studies are needed to investigate the burden of RSV infection in patients hospitalized in PICU, including children with NMD/CAA.

Impact of Respiratory Syncytial Virus-Confirmed Hospitalizations on Caregivers of US Preterm Infants

This study assessed the impact of respiratory syncytial virus-confirmed hospitalizations (RSVH) on caregivers of high-risk preterm infants. Caregivers for infants born at 29 to 35 weeks' gestational age and hospitalized for confirmed RSV disease responded to measures of self-rated and perceived infant stress (1-7; 7 = very stressful), perceived infant health (0-100; 100 = best imaginable health), and productivity impairment. Data were collected at hospital discharge through 1 month post-discharge. Caregiver responses indicated high stress levels, poor health, and productivity loss were reported at discharge; however, steady improvements were seen through 1 month post-discharge: caregiver-rated stress (from 6 to 2), infant stress (5 to 1), caregiver-perceived infant health (64 to 84), and productivity loss (mothers: 91% to 31%; fathers: 81% to 18%). Qualitative results indicated emotional impact, family routine disruption, financial concerns, and medical concerns persisted at 1 month post-discharge. This study found the caregiver burden of RSVH persists at least 1 month beyond discharge.

Infant Immune Response to Respiratory Viral Infections

Of all respiratory viruses that affect infants, respiratory syncytial virus (RSV) and rhinovirus (RV) represent the leading pathogens causing acute disease (bronchiolitis) and are associated with the development of recurrent wheezing and asthma. The immune system in infants is still developing, and several factors contribute to their increased susceptibility to viral infections. These factors include differences in pathogen detection, weaker interferon responses, lack of immunologic memory toward the invading pathogen, and T-cell responses that are balanced to promote tolerance and restrain inflammation. These aspects are reviewed here with a focus on RSV and RV infections.

Dichloro-Phenyl-Benzotriazoles: A New Selective Class of Human Respiratory Syncytial Virus Entry Inhibitors

Human Respiratory Syncytial Virus (RSV) is the primary cause of bronchopneumonia in infants and children worldwide. Clinical studies have shown that early treatments of RSV patients with ribavirin improve prognosis, even if the use of this drug is limited due to myelosuppression and toxicity effects. Furthermore, effective vaccines to prevent RSV infection are currently unavailable. Thus, the development of highly effective and specific antiviral drugs for pre-exposure prophylaxis and/or treatment of RSV infections is a compelling need. In the quest of new RSV inhibitors, in this work we evaluated the antiviral activity of a series of variously substituted 5,6-dichloro-1-phenyl-1(2)H-benzo[d][1,2,3]triazole derivatives in cell-based assays. Several 1- and 2-phenyl-benzotriazoles resulted fairly potent (μM concentrations) inhibitors of RSV infection in plaque reduction assays, accompanied by low cytotoxicity in human highly dividing T lymphoid-derived cells and primary cell lines. Contextually, no inhibitory effects were observed against other RNA or DNA viruses assayed, suggesting specific activity against RSV. Further results revealed that the lead compound 10d was active during the early phase of the RSV infection cycle. To understand whether 10d interfered with virus attachment to target cells or virus-cell fusion events, inhibitory activity tests against the RSV mutant strain B1 cp-52—expressing only the F envelope glycoprotein—and a plasmid-based reporter assay that quantifies the bioactivity of viral entry were also performed. The overall biological results, in conjunction with in silico modeling studies, supported the conclusion that the RSV fusion process could be the target of this new series of compounds.

Comparisons between ethnic groups in hospitalizations for respiratory syncytial virus bronchiolitis in Israel

BACKGROUND

Ethnic disparities have been shown in respiratory syncytial virus (RSV) bronchiolitis. However, it is unclear whether such differences are related to access to care. We compared demographic and clinical characteristics of Arab and Jewish children hospitalized for RSV bronchiolitis in Israel, a country with universal health insurance.

METHODS

We reviewed the medical records of all children (n = 309) aged less than 24 months who were hospitalized with RSV between 2008 and 2011 in one medical center in Israel. Demographic, clinical, laboratory and radiological data were collected. The RSV antigen was identified using immunochromatography.

RESULTS

The annual incidence of RSV hospitalization was 5.4/1000 and 6.8/1000 among Arab and Jewish children, respectively. Arab patients were significantly younger and had significantly younger parents; most lived in low socioeconomic status towns (93.7% vs. 13.3%; p<0.001) and had more siblings (median 2 vs. 1; p = 0.01) compared to Jewish patients. Disease severity did not differ between the two ethnic groups (p = 0.3). The main predictors of severe illness were having pneumonia (adjusted odds ratio [OR] 3.86; 95% confidence intervals [CI] 1.87-7.97) and history of respiratory diseases (adjusted OR 3.89; 95% CI 1.22-12.38).

CONCLUSIONS

The incidence of hospitalizations for RSV bronchiolitis tended to be higher among Jewish than Arab children, possibly due to differences in health care utilization patterns. Differences between the Jewish and Arab patients in demographic factors likely mirror differences between the groups in the general population. Pneumonia, and not ethnicity, affected the severity of RSV bronchiolitis.

RNA respiratory viral infections in solid organ transplant recipients: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of RNA respiratory viral infections in the pre‐ and post‐transplant period. Viruses reviewed include influenza, respiratory syncytial virus (RSV), parainfluenza, rhinovirus, human metapneumovirus (hMPV), and coronavirus. Diagnosis is by nucleic acid testing due to improved sensitivity, specificity, broad range of detection of viral pathogens, automatization, and turnaround time. Respiratory viral infections may be associated with acute rejection and chronic lung allograft dysfunction in lung transplant recipients. The cornerstone of influenza prevention is annual vaccination and in some cases antiviral prophylaxis. Treatment with neuraminidase inhibitors and other antivirals is reviewed. Prevention of RSV is limited to prophylaxis with palivizumab in select children. Therapy of RSV upper or lower tract disease is controversial but may include oral or aerosolized ribavirin in some populations. There are no approved vaccines or licensed antivirals for parainfluenza, rhinovirus, hMPV, and coronavirus. Potential management strategies for these viruses are given. Future studies should include prospective trials using contemporary molecular diagnostics to understand the true epidemiology, clinical spectrum, and long‐term consequences of respiratory viruses as well as to define preventative and therapeutic measures.

Novel genetically-modified chimpanzee adenovirus and MVA-vectored respiratory syncytial virus vaccine safely boosts humoral and cellular immunity in healthy older adults

OBJECTIVES

Respiratory syncytial virus (RSV) causes respiratory infection across the world, with infants and the elderly at particular risk of developing severe disease and death. The replication-defective chimpanzee adenovirus (PanAd3-RSV) and modified vaccinia virus Ankara (MVA-RSV) vaccines were shown to be safe and immunogenic in young healthy adults. Here we report an extension to this first-in-man vaccine trial to include healthy older adults aged 60-75 years.

METHODS

We evaluated the safety and immunogenicity of a single dose of MVA-RSV given by intra-muscular (IM) injection (n = 6), two doses of IM PanAd3-RSV given 4-weeks apart (n = 6), IM PanAd3-RSV prime and IM MVA-RSV boost 8-weeks later (n = 6), intra-nasal (IN) spray of PanAd3-RSV prime and IM MVA-RSV boost 8-weeks later (n = 6), or no vaccine (n = 6). Safety measures included all adverse events within one week of vaccination and blood monitoring. Immunogenicity measures included serum antibody responses (RSV- and PanAd3-neutralising antibody titres measured by plaque-reduction neutralisation and SEAP assays, respectively), peripheral B-cell immune responses (frequencies of F-specific IgG and IgA antibody secreting cells and memory B-cells by ex vivo and cultured dual-colour ELISpot assays respectively), and peripheral RSV-specific T-cell immune responses (frequencies of IFNγ-producing T-cells by ex vivo ELISpot and CD4+/CD8+/Tfh-like cell frequencies by ICS/FACS assay).

RESULTS

The vaccines were safe and well tolerated. Compared with each individual baseline immunity the mean fold-changes in serum RSV-neutralising antibody, appearance and magnitude of F-specific IgG and IgA ASCs and expansion of CD4+/CD8+ IFNγ-producing T-cells in peripheral circulation were comparable to the results seen from younger healthy adults who received the same vaccine combination and dose. There were little/no IgA memory B-cell responses in younger and older adults. Expansion of IFNγ-producing T-cells was most marked in older adults following IM prime, with balanced CD4+ and CD8+ T cell responses. The RSV-specific immune responses to vaccination did not appear to be attenuated in the presence of PanAd3 (vector) neutralising antibody.

CONCLUSIONS

PanAd3-RSV and MVA-RSV was safe and immunogenic in older adults and the parallel induction of RSV-specific humoral and cellular immunity merits further assessment in providing protection from severe disease.

Outcomes related to respiratory syncytial virus with an abbreviated palivizumab regimen in children with congenital heart disease: a descriptive analysis

BACKGROUND

It has been hypothesized that 4 doses of palivizumab, a neutralizing monoclonal antibody against respiratory syncytial virus (RSV), administered during a fixed-date RSV season may reduce hospital admissions comparably to the standard 5-dose schedule. We report outcomes in children with congenital heart disease approved to receive this 4-dose palivizumab schedule in British Columbia.

METHODS

We performed a population-based descriptive cohort analysis of all 406 approved palivizumab courses over 4 seasons (2012/13 to 2015/16) in 325 children with hemodynamically significant congenital heart disease enrolled in the British Columbia RSV Immunoprophylaxis Program. The primary outcome was in-season hospital admission for potential RSV-related lower respiratory tract infection (LRTI). Secondary outcomes include timing of admission in relation to dosing. Analysis was by intention-to-treat.

RESULTS

Of the 406 approved palivizumab courses, 391 were administered. In 33 cases (8.4%), an additional dose was given immediately after cardiac bypass surgery. There were 17 RSV-confirmed hospital admissions (median age of children 5.9 mo [interquartile range 4-10 mo]) and 8 admissions in which the child was not tested for RSV, for a maximum of 25 potential RSV-related admissions (6.2 per 100 approvals [95% confidence interval 4.0-9.0]). Twenty-four (96%) of the 25 admissions occurred within the 4-dose palivizumab dosing period, and the remaining admission occurred 52 days after the fourth dose. Sixty-four (72%) of 89 admissions were RSV-negative; the baseline clinical characteristics of these children were not different from those of children with RSV-confirmed admissions.

INTERPRETATION

In infants with hemodynamically significant congenital heart disease, a 4-dose fixed-date palivizumab schedule over a 6-month season provided seasonal protection comparable to that in a clinical trial involving a standard 5-dose schedule. Because RSV was responsible for only 19% of admissions for LRTI in our cohort, it is critical to continue to emphasize other preventive measures, including family education toward proper hand hygiene, breast-feeding and limiting infectious exposures in children at high risk.

Should we use Palivizumab immunoprophylaxis for infants against respiratory syncytial virus? - a cost-utility analysis

BACKGROUND

Passive immunization against RSV (Respiratory Syncytial Virus) is given in most western countries (including Israel) to infants of high risk groups such as premature babies, and infants with Congenital Heart Disease or Congenital Lung Disease. However, immunoprophylaxis costs are extremely high ($2800-$4200 per infant). Using cost-utility analysis criteria, we evaluate whether it is justified to expand, continue or restrict nationwide immunoprophylaxis using palivizumab of high risk infants against RSV.

METHODS

Epidemiological, demographic, health service utilisation and economic data were integrated from primary (National Hospitalization Data, etc.) and secondary data sources (ie: from published articles) into a spread-sheet to calculate the cost per averted disability-adjusted life year (DALY) of vaccinating various infant risk groups. Costs of intervention included antibody plus administration costs. Treatment savings and DALYs averted were estimated from applying vaccine efficacy data to relative risks of being hospitalised and treated for RSV, including possible long-term sequelae like asthma and wheezing.

RESULTS

For all the groups RSV immunoprophylaxis is clearly not cost effective as its cost per averted DALY exceeds the $105,986 guideline representing thrice the per capita Gross Domestic Product. Vaccine price would have to fall by 48.1% in order to justify vaccinating Congenital Heart Disease or Congenital Lung Disease risk groups respectively on pure cost-effectiveness grounds. For premature babies of < 29 weeks, 29-32 and 33-36 weeks gestation, decreases of 36.8%, 54.5% and 83.3% respectively in vaccine price are required.

CONCLUSIONS

Based solely on cost-utility analysis, at current price levels it is difficult to justify the current indications for passive vaccination with Palivizumab against RSV. However, if the manufacturers would reduce the price by 54.5% then it would be cost-effective to vaccinate the Congenital Heart Disease or Congenital Lung Disease risk groups as well as premature babies born before the 33rd week of gestation.

War against respiratory syncytial virus. An 8-year experience at a tertiary hospital

Objectives:

To assess the respiratory syncytial virus (RSV) infection incidence rate through the analysis of data collected before and after implementation of a new palivizumab dosing regimen customized for a high-risk Saudi population.

Methods:

This was a retrospective cohort study performed at Prince Sultan Military Medical City, Riyadh, Saudi Arabia between November 2009 and

April 2017 on 1704 high risk Saudi young children and comparing 3 palivizumab regimens: a 4-week interval dosing regimen starting in either November or mid-September and a 3-week interval dosing regimen starting in mid-September.

Results:

Despite a decrease in the incidence rate of RSV infection with the three-week interval regimen (3.9% versus 5.9% in seasons 1 and 9.1% in seasons 2), we did not find significant differences among the 3 groups.

Conclusion:

Expanded use of palivizumab in newborn children could improve outcomes, but further investigation and a careful cost analysis are required.

Respiratory Syncytial Virus Hospitalizations among U.S. Preterm Infants Compared with Term Infants Before and After the 2014 American Academy of Pediatrics Guidance on Immunoprophylaxis: 2012-2016

OBJECTIVE

The objective of this study was to compare risk for respiratory syncytial virus (RSV) hospitalizations (RSVH) for preterm infants 29 to 34 weeks gestational age (wGA) versus term infants before and after 2014 guidance changes for immunoprophylaxis (IP), using data from the 2012 to 2016 RSV seasons.

STUDY DESIGN

Using commercial and Medicaid claims databases, infants born between July 1, 2011 and June 30, 2016 were categorized as preterm or term. RSVH during the RSV season (November-March) were identified for infants aged <6 months and rate ratios (RRs) for hospitalization comparing preterm and term infants were calculated. Difference-in-difference models were fit to evaluate the changes in hospitalization risks in preterm versus term infants from 2012 to 2014 seasons to 2014 to 2016 seasons.

RESULTS

In all seasons, preterm infants had higher RSVH rates than term infants. Seasonal RRs prior to the guidance change for preterm wGA categories versus term infants ranged from 1.6 to 3.4. After the guidance change, the seasonal RRs ranged from 2.6 to 5.6. In 2014 to 2016, the risk associated with prematurity of 29 to 34 wGA versus term was significantly higher than in 2012 to 2014 (P<0.0001 for commercial and Medicaid samples).

CONCLUSION

In infants aged <6 months, the risk for RSVH for infants 29 to 34 wGA compared with term infants increased significantly after the RSV IP recommendations became more restrictive.

Improving the prescribing of palivizumab

AIM

Palivizumab prevents respiratory syncytial virus (RSV) in children at high risk of severe disease. This paper reviews the use and effectiveness of palivizumab at two tertiary paediatric hospitals (hospitals A and B) in New South Wales, Australia.

METHODS

Children prescribed palivizumab during the pre-intervention period, 1 January 2013 until 31 December 2014, were compared with children under 2 years of age who were admitted to paediatric intensive care units (PICUs) with an RSV infection. Eligibility for palivizumab was determined. To improve evidence-based utilisation of palivizumab, a 'streamlined palivizumab individual patient use' (IPU) pro forma was introduced at hospital A during 2015, and its applicability was reviewed.

RESULTS

In the 2 years prior to implementing the streamlined IPU, 47 children received palivizumab, with 87% at hospital A. Of the children at hospital A, 32% did not meet the guidelines, and 32% did not complete the course. While 13% of children admitted to PICU for RSV infection were eligible for palivizumab, none received it prior to admission. In 2015, 16 streamlined IPUs were submitted, and 11 patients received palivizumab. Of these patients, 27% did not meet the guidelines, and 63% did not complete the course. Of the children who received palivizumab during the three RSV seasons, one developed an RSV infection, and none were admitted to PICU.

CONCLUSIONS

Palivizumab is often prescribed without meeting recognised best practice guidelines, and patients eligible are frequently not prescribed palivizumab. The streamlined IPU, implemented in hospital A, excluded patients who did not meet guidelines. The pro forma needs further refinement, and complementary strategies introduced to improve compliance.

Respiratory syncytial virus hospitalization and incurred morbidities the season after prophylaxis

OBJECTIVES

The primary objective of this study was to determine the incidence and incurred morbidities of Respiratory syncytial virus (RSV)-related hospitalization (RSVH), the season following completion of prophylaxis.

METHODS

A retrospective study was conducted of all infants enrolled in a prophylaxis clinic in one institution during the 2009 to 2014 RSV seasons. RSV infection was identified by Diseases codes and confirmed by RSV-positivity. Data were classified into five groups based on indications for prophylaxis. The incidence of RSVH was calculated. For each subgroup, differences in characteristics between children with and without RSVH were analyzed by independent t test or chi-square test.

RESULTS

During five RSV seasons, 827 infants were enrolled. RSVH incidence the season following prophylaxis was 2.1% (n=17/827). Children with chronic lung disease (CLD) had the highest RSVH incidence (7.7%; n=4/52) followed by preterms 33 to 35 weeks gestation (2.5%; n=4/162), those with complex medical disorders (2.2%; n=3/135), those with congenital heart disease (1.5%; n=1/66) and preterms less than or equal to 32 weeks gestation (1.2%; n=5/412). There was no statistically significant association between indications for prophylaxis and RSVH (Fisher exact test, P=0.060). The odds of RSVH were 4.9 times greater (odds ratio [OR]=4.9; 95% CI: 1.53, 15.55; P=0.007) in CLD compared to those without CLD. The median length of RSVH stay was 4 days; 58.8% (n=10/17) required oxygen (median 1 day); 29.4% (n=5/17) required intensive care.

CONCLUSIONS

Infants with CLD are at highest risk for RSVH in the season postprophylaxis and may merit palivizumab for more than two seasons dependent on disease severity. However, larger prospective studies are necessary to confirm the findings before embarking on a strategy of providing prophylaxis for a third RSV season.

Respiratory syncytial virus (RSV) infection in children with medical complexity

Children with medical complexity (CMC) are vulnerable to respiratory illness hospitalization (RIH) and respiratory syncytial virus (RSV)-related hospitalization (RSVH) due to multisystem disorders and compromised airways. It is unknown whether RSV prophylaxis is effective, or if RSVH is associated with significant morbidities in CMC. The study objectives were to (1) determine the incidence of RSV-related infection in prophylaxed CMC during the first 3 years of life and (2) assess the burden of illness following RSVH. A single tertiary center, retrospective study, was conducted of CMC who received palivizumab during the 2012-2016 RSV seasons. Fifty-four subjects were enrolled; most received one (38.9%, n = 21) or two (57.4%, n = 31) seasons of prophylaxis (mean = 4.2 [SD = 1.24], palivizumab doses per season). The cohort comprised children with multiple medical conditions (n = 22, 40.8%), tracheostomy (n = 18, 33.3%), and invasive (n = 10, 18.5%) or non-invasive (n = 4, 7.4%) ventilation. Of the CMC, 24 were hospitalized 47 times for a viral-related respiratory illness. RSV incidence in the first 3 years of life was 7.4%. Viral-related RIH and RSVH rates were 44.4% (n = 24/54) and 1.9% (n = 1/54), respectively. Of the four RSV-positive children, one was ventilated for 9 days, two acquired nosocomial RSV that was managed on the ward, and one was discharged home under close complex care supervision. All four RSV-positive cases required additional oxygen during their illness. CMC experience a high viral-related RIH rate and palivizumab likely minimizes RSV-related events and associated morbidities. The efficacy of palivizumab in CMC, especially in those ≤ 3 years, should be prospectively evaluated.

Bispecific antibodies: Potential immunotherapies for HIV treatment

Bispecific (bs) antibodies (Abs, bsAbs) are engineered immunoglobulins that contain two different antigen-binding sites in one molecule. bsAbs can be divided in two molecular formats; the IgG-like and non-IgG like. The structural elements of each format have implications for engaging the immune system. Elimination of HIV will need sophisticated approaches with immunotherapies being one of the strategies under investigation. Furthermore, HIV genetic variability and functional compromise of the adaptive CTL response complicate the potential usefulness of some immunotherapeutic strategies. Inclusion of novel HIV neutralizing Abs with high potency and breadth as components of bsAbs could represent alternative strategies for virus elimination by harnessing the adaptive immune response in vivo.

Respiratory syncytial virus prophylaxis and the "special population"

Bronchiolitis is the most frequent airway infection in the first 2 years of life, and the respiratory syncytial virus (RSV) is the most frequently responsible virus. In selected high-risk groups, RSV may cause severe respiratory disease leading to hospitalization, need for mechanical ventilation, and even death. These high-risk groups include children with congenital heart disease, infants with neuromuscular impairment, cystic fibrosis, Down Syndrome, immunodeficiency syndromes and others specific conditions. In these high-risk populations defined in literature as "special population", a 3- to 10-fold increase in the rate of RSV hospitalization has been observed, justifying RSV specific prophylaxis with palivizumab, a monoclonal antibody that binds a viral glycoprotein epitope and blocks the link between RSV and target cell. Evidence of safety and efficacy of RSV prophylaxis in these populations is lacking. Given the low incidence of these conditions, randomized clinical trials are not feasible. The purpose of this paper is to give an update from the literature of various conditions at higher risk to develop severe RSV infection, and to offer an overview of the efficacy of palivizumab in preventing RSV infection in these specific populations.

RSV prophylaxis in premature infants

Infants born prematurely before 37 weeks of gestational age (GA) have particular anatomical, immunological and metabolic characteristics that predispose them, even in the absence of diseases at birth, to severe morbidity. Respiratory syncytial virus (RSV) is the leading cause of hospitalization for lower respiratory tract infections (LRTI) in the first year of life, as well as an important cause of respiratory outcomes as recurrent wheezing in industrialized countries or mortality in developing countries. Prematurity is an important risk factor for hospitalization for severe RSV disease, but epidemiological, environmental and demographic risk factors also play a role in RSV infection. Currently, there is no effective antiviral therapy for the treatment of RSV infection, nor the possibility of using maternal immunization or vaccination of children to prevent infection, although numerous preclinical and clinical studies are still ongoing. Passive immunization with palivizumab has been shown to be safe and effective in preventing RSV hospitalization in children at greater risk of contracting a serious infection. Costs associated with palivizumab prophylaxis and its monthly intramuscularly administration has prompted many health institutions of different countries to implement specific recommendations, with the aim of protecting at risk infants for whom RSV infection is likely to cause serious illness or death. The cost-effectiveness ratio of prophylaxis, related to reduce hospitalization costs and the impact of the burden of RSV disease worldwide, greatly affects the drafting and the adoption of specific recommendations and the adherence to them, concerning the passive immunization with palivizumab.

Risk Factors and Main Indications for Palivizumab Prophylaxis in a Second Season Population: Results From the German Synagis Registry 2009-2016

BACKGROUND

After national recommendations, palivizumab is administered in Germany to high-risk infants to prevent hospitalizations related to respiratory syncytial virus (RSV) infection. Limited data are available to characterize those children who receive palivizumab in 2 consecutive RSV seasons.

METHODS

This was a comparative analysis of data from a postmarketing observational study (German SYNAGIS Registry, AbbVie Germany GmbH & Co.KG, Wiesbaden) detailing RSV-related risk factors and main indications for palivizumab in 920 children who received at ≥1 palivizumab injection in a second season between 2010 and 2016 [second season population (SSP)].

RESULTS

Median birth weight and gestational age at birth as well as the proportion of children with hemodynamically significant congenital heart disease, with any form of chronic lung disease of prematurity or with any form of neuromuscular impairment, were significantly higher in the SSP. Accordingly, hemodynamically significant congenital heart disease, chronic lung disease and other reasons (including neuromuscular impairment) and not prematurity were the main indications for palivizumab in the SSP. The RSV-related hospitalization rate confirmed by viral testing in the SSP (receiving palivizumab prophylaxis) was 0.9%. No deaths due to RSV were reported.

CONCLUSIONS

Second season recipients of palivizumab differ from one season recipients of palivizumab in terms of risk factors and main indications for prophylaxis. Keeping in mind the limitations of an uncontrolled prospective observational study, these results support the effectiveness of palivizumab (concerning the RSV rehospitalization rate) and do not reveal new safety alerts in a large SSP.

Down Syndrome and the Risk of Severe RSV Infection: A Meta-analysis

CONTEXT

Down syndrome (DS) is the most common chromosomal condition in live-born infants worldwide, and lower respiratory infection caused by respiratory syncytial virus (RSV) is a leading cause of hospital admissions.

OBJECTIVE

To evaluate RSV-associated morbidity among children with DS compared with a population without DS.

DATA SOURCES

Four electronic databases were searched.

STUDY SELECTION

All cohorts or case-control studies of DS with an assessment of RSV infection and the associated morbidity or mortality were included without language restriction.

DATA EXTRACTION

Two reviewers independently reviewed all studies. The primary outcomes were hospital admission and mortality. Secondary outcomes included length of hospital stay, oxygen requirement, ICU admission, need for respiratory support, and additional medication use.

RESULTS

Twelve studies (n = 1 149 171) from 10 different countries met the inclusion criteria; 10 studies were cohort studies, 1 study was retrospective, and 1 study had both designs. DS was associated with a higher risk of hospitalization (odds ratio [OR]: 8.69; 95% confidence interval [CI]: 7.33-10.30; I² = 11%) and mortality (OR: 9.4; 95% CI: 2.26-39.15; I² = 38%) compared with what was seen in controls. Children with DS had an increased length of hospital stay (mean difference: 4.73 days; 95% CI: 2.12-7.33; I² = 0%), oxygen requirement (OR: 6.53; 95% CI: 2.22-19.19; I² = 0%), ICU admission (OR: 2.56; 95% CI: 1.17-5.59; I² = 0%), need for mechanical ventilation (OR: 2.56; 95% CI: 1.17-5.59; I² = 0%), and additional medication use (OR: 2.65 [95% CI: 1.38-5.08; I² = 0%] for systemic corticosteroids and OR: 5.82 [95% CI: 2.66-12.69; I² = 0%] for antibiotics) than controls.

LIMITATIONS

DS subgroups with and without other additional risk factors were not reported in all of the included studies.

CONCLUSIONS

Children with DS had a significantly higher risk of severe RSV infection than children without DS.

[Assessment of the program for use of the monoclonal antibody palivizumab in São Paulo State, Brazil]

This study aimed to assess the program for use of the monoclonal antibody palivizumab in São Paulo State, Brazil. The evaluation adopted the frame of reference proposed by Donabedian, and the data were discussed on the basis of the guidelines from the Ruling on the use of palivizumab in the national network and in the Manual on Standards and Procedures for Vaccination. Sixteen application services in the state were included, with 693 children/mothers enrolled in the program in 2014 (85.1% of the eligible population). For the structure and process evaluation, scores were created that allowed classifying the application services as adequate, partially adequate, and inadequate (non-compliance rates were ≤ 10%, 11-20%, and > 20%, respectively). Results were evaluated according to the association between failure to administer palivizumab and need for hospitalization due to respiratory disease/symptoms, based on the point and interval odds ratios, with 95% confidence interval and critical p-value < 0.05. Of the 11 application services whose structure was classified as adequate, only two showed adequate process, four showed inadequate process, and five partially adequate process. Risk of ICU admission due to respiratory disease/symptoms increased on average by 30% for each failure (p = 0.003; OR = 1.30; 95%CI: 1.09-1.55). In conclusion, having a favorable structure for the program for use of palivizumab in São Paulo State did not necessarily result in an adequate process. In general, the situation with the structure was better than the process. All doses of the monoclonal antibody need to be administered in order to prevent hospitalization from respiratory disease/symptoms.

Bronchiolitis in children: The Saudi initiative of bronchiolitis diagnosis, management, and prevention (SIBRO)

Bronchiolitis is the leading cause of admissions in children less than two years of age. It has been recognized as highly debated for many decades. Despite the abundance of literature and the well-recognized importance of palivizumab in the high risk groups, and despite the existence of numerous, high-quality, recent guidelines on bronchiolitis, the number of admissions continues to increase. Only supportive therapy and few therapeutic interventions are evidence based and proved to be effective. Since Respiratory Syncytial Virus (RSV) is the major cause of bronchiolitis, we will focus on this virus mostly in high risk groups like the premature babies and children with chronic lung disease and cardiac abnormalities. Further, the prevention of RSV with palivizumab in the high risk groups is effective and well known since 1998; we will discuss the updated criteria for allocating infants to this treatment, as this medication is expensive and should be utilized in the best condition. Usually, diagnosis of bronchiolitis is not challenging, however there has been historically no universally accepted and validated scoring system to assess the severity of the condition. Severe RSV, especially in high risk children, is unique because it can cause serious respiratory sequelae. Currently there is no effective curative treatment for bronchiolitis. The utility of different therapeutic interventions is worth a discussion.

Respiratory virus prophylaxis in congenital heart disease

Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infections and causes up to 200,000 infant deaths a year worldwide. The average rate of hospitalization for severe RSV infection is 5 per 1000 children, and the rate is three-times higher in those with congenital heart disease (CHD). Palivizumab, a monoclonal antibody, reduces hospitalization rates and intensive care admissions. It is used prophylactically and is administered as monthly doses during the RSV season. Hemodynamically unstable CHD is the most susceptible CHD to a severe episode of RSV infection. This review explores current evidence surrounding therapies, patterns of infection and identifies groups which may still be vulnerable to severe RSV infection.

Palivizumab use in infants with Down syndrome-report from the German Synagis™ Registry 2009-2016

Infants with Down syndrome (DS) face an increased risk of respiratory tract infections. Recent studies describe DS as independent risk factor for a complicated clinical course in infants with respiratory syncytial virus (RSV) infection. The prospective observational German Synagis™ Registry comprises data from 249 children below 25 months of age with DS and palivizumab prophylaxis 2009-2016 (1191 administrations; mean 4.8 per patient and season). The median gestational age and the birth weight in patients without and with DS were 31 versus 37 weeks (P < 0.001) and 1590 versus 2750 g, respectively (P < 0.001). Patients with DS significantly more often had congenital heart disease (CHD), siblings in kindergarten or school, treatment with oxygen at home, immunodeficiency, and neuromuscular impairment. The RSV-related hospitalization rate in patients with DS was 1.20%; the hospitalization rate in patients without DS was 0.71%.

CONCLUSION

Data from 249 children with DS receiving palivizumab prophylaxis in seven consecutive RSV seasons (2009-2016) in Germany reveal important differences between patients with and without DS concerning the main indication for palivizumab use and additional risk factors. Bearing in mind the limitations of an uncontrolled postmarketing observational study, the results confirm the field effectiveness of palivizumab prophylaxis in this special population. What is Known: • Recent studies describe the Down syndrome as independent risk factor for a complicated clinical course in infants with RSV infection. What is New: • Compared with other infants receiving palivizumab prophylaxis, patients with Down syndrome significantly more often had congenital heart disease, siblings in kindergarten or school, treatment with oxygen at home, immunodeficiency, and neuromuscular impairment. • In infants with palivizumab prophylaxis breakthrough, RSV-related hospitalization rates were not significantly higher in those with Down syndrome.

Respiratory syncytial virus prophylaxis in cystic fibrosis: the Canadian registry of palivizumab data (2005-2016)

Respiratory syncytial virus (RSV) may cause severe illness in cystic fibrosis (CF) children, but recommendations vary on prophylaxis. CARESS is a prospective registry of children who received palivizumab in 32 Canadian sites from 2005 to 2016. Demographic data were collected at enrollment and respiratory illness-related events recorded monthly. We reviewed respiratory illness hospitalization (RIH) and RSV hospitalization (RSVH) in CF children aged < 24 months versus those prophylaxed for standard indications (SI; prematurity, chronic lung disease [CLD] and congenital heart disease [CHD]), and complex medical disorders (CM). Of 23,228 children analyzed, 19,452 (83.8%) were SI, 3349 (14.4%) were CM, and 427 (1.8%) were CF. CF children were more likely to be Caucasian, heavier at birth and enrollment, and less likely to have a sibling or live in crowded conditions. CF children were similar to the other groups in daycare attendance, history of atopy, and exposure to smoking. RIH incidences were 4.3% (premature), 13.8% CLD, 11.5% CHD, 11.7% CM, and 6.8% CF. RSVH incidence in CF children was similar to that in the SI and CM groups: 1.1, 1.5, and 2.0% groups respectively. Cox regression analyses showed that compared to CF children, the HRs for RSVH in SI (HR 2.0 95% CI 0.5-8.3, p = 0.3) and CM (HR 2.4, 95% CI 0.6-9.8, p = 0.2) did not differ. CF children are equally at risk for RSVH relative to those prophylaxed for other indications. Pending robust evidence from prospective trials, palivizumab could perhaps be considered in the interim, for young CF patients born early during the RSV season with evidence of serious lung disease.

Therapeutic antibodies: A new era in the treatment of respiratory diseases?

Respiratory diseases affect millions of people worldwide, and account for significant levels of disability and mortality. The treatment of lung cancer and asthma with therapeutic antibodies (Abs) is a breakthrough that opens up new paradigms for the management of respiratory diseases. Antibodies are becoming increasingly important in respiratory medicine; dozens of Abs have received marketing approval, and many more are currently in clinical development. Most of these Abs target asthma, lung cancer and respiratory infections, while very few target chronic obstructive pulmonary disease - one of the most common non-communicable causes of death - and idiopathic pulmonary fibrosis. Here, we review Abs approved for or in clinical development for the treatment of respiratory diseases. We notably highlight their molecular mechanisms, strengths, and likely future trends.

Risk scoring tool to predict respiratory syncytial virus hospitalisation in premature infants

BACKGROUND

The objective was to develop a risk scoring tool which predicts respiratory syncytial virus hospitalisation (RSVH) in moderate-late preterm infants (32-35 weeks' gestational age) in the Northern Hemisphere.

METHODS

Risk factors for RSVH were pooled from six observational studies of infants born 32 weeks and 0 days to 35 weeks and 6 days without comorbidity from 2000 to 2014. Of 13 475 infants, 484 had RSVH in the first year of life. Logistic regression was used to identify the most predictive risk factors, based on area under the receiver operating characteristic curve (AUROC). The model was validated internally by 100-fold bootstrapping and externally with data from a seventh observational study. The model coefficients were converted into rounded multipliers, stratified into risk groups, and number needed to treat (NNT) calculated.

RESULTS

The risk factors identified in the model included (i) proximity of birth to the RSV season; (ii) second-hand smoke exposure; and (iii) siblings and/or daycare. The AUROC was 0.773 (sensitivity: 68.9%; specificity: 73.0%). The mean AUROC from internal bootstrapping was 0.773. For external validation with data from Ireland, the AUROC was 0.707 using Irish coefficients and 0.681 using source model coefficients. Cut-off scores for RSVH were ≤19 for low- (1.0%), 20-45 for moderate- (3.3%), and 50-56 (9.5%) for high-risk infants. The high-risk group captured 62.0% of RSVHs within 23.6% of the total population (NNT 15.3).

CONCLUSIONS

This risk scoring tool has good predictive accuracy and can improve targeting for RSVH prevention in moderate-late preterm infants.

Efficacy of a Novel Palivizumab Prophylaxis Protocol for Respiratory Syncytial Virus Infection in Congenital Heart Disease: A Multicenter Study

OBJECTIVE

To analyze the efficacy of a novel palivizumab protocol for hemodynamically significant congenital heart disease (hsCHD) in subtropical areas without clear respiratory syncytial virus seasonality.

STUDY DESIGN

Since July 2013, the National Health Insurance program has provided reimbursement for palivizumab prophylaxis with a novel monthly protocol in selected patients with hsCHD under 1 year of age. We performed a multicenter study to assess the trend of respiratory syncytial virus hospitalizations in patients with hsCHD from 2010 to 2016 during the prepalivizumab, transition, and postpalivizumab periods, and compared treatment and propensity-matched control groups.

RESULTS

A total of 747 patients were enrolled in the study group and 809 in the control group. The male:female was 836:720. Cyanotic CHD was observed in 42.9% of patients. The mean age at diagnosis of CHD was 32.9 days. After 516 685 patient-days of follow-up and a mean of 3.9 doses of palivizumab in the treatment group, respiratory syncytial virus hospitalization rates decreased by 53% and 49% before and after match compared with the control group (P = .009 and .029, respectively). Hospitalization days and intensive care unit admission rate also decreased similarly in the treatment group. The efficacy of this protocol was more prominent in patients with cyanotic hsCHD. The annual respiratory syncytial virus-associated hospitalization rates also decreased significantly from the prepalivizumab to the palivizumab period (from 4.8% to 2.0%; P = .038).

CONCLUSION

Palivizumab prophylaxis through the novel monthly protocol for patients with hsCHD is effective in reducing respiratory syncytial virus-related hospitalizations.

Reformatting palivizumab and motavizumab from IgG to human IgA impairs their efficacy against RSV infection in vitro and in vivo

Respiratory syncytial virus (RSV) infection is a leading cause of hospitalization and mortality in young children. Protective therapy options are limited. Currently, palivizumab, a monoclonal IgG1 antibody, is the only licensed drug for RSV prophylaxis, although other IgG antibody candidates are being evaluated. However, at the respiratory mucosa, IgA antibodies are most abundant and act as the first line of defense against invading pathogens. Therefore, it would be logical to explore the potential of recombinant human IgA antibodies to protect against viral respiratory infection, but very little research on the topic has been published. Moreover, it is unknown whether human antibodies of the IgA isotype are better suited than those of the IgG isotype as antiviral drugs to combat respiratory infections. To address this, we generated various human IgA antibody formats of palivizumab and motavizumab, two well-characterized human IgG1 anti-RSV antibodies. We evaluated their efficacy to prevent RSV infection in vitro and in vivo and found similar, but somewhat decreased efficacy for different IgA subclasses and formats. Thus, reformatting palivizumab or motavizumab into IgA reduces the antiviral potency of either antibody. Moreover, our results indicate that the efficacy of intranasal IgA prophylaxis against RSV infection in human FcαRI transgenic mice is independent of Fc receptor expression.

Hospital Readmissions in Children with Pulmonary Hypertension: A Multi-Institutional Analysis

OBJECTIVE

To assess the rate of and risk factors for 30-day hospital readmission in children with pulmonary hypertension.

STUDY DESIGN

The Pediatric Health Information System database was analyzed for patients ≤18 years old with pulmonary hypertension (International Classification of Diseases, Ninth Revision, diagnosis codes of 416.0, 416.1, 416.8, or 416.9) admitted from 2005 through 2014. A generalized hierarchical regression model was used to determine significant ORs and 95% CIs associated with 30-day readmission.

RESULTS

A total of 13580 patients met inclusion criteria (median age 1.7 years [IQR 0.3-8.7], 45.3% with congenital heart disease). Admissions increased 4-fold throughout the study period. Associated hospital charges increased from $119 million in 2004 to $929 million in 2014. During initial admission, 57.4% of patients required admission to the intensive care unit, and 48.2% required mechanical ventilation. The 30-day readmission rate was 26.3%. Mortality during readmission was 4.2%. Factors increasing odds of readmission included a lower hospital volume of pulmonary hypertension admissions (1.41 [1.23-1.57], P < .001) and having public insurance (1.26 [1.16-1.38], P < .001). Decreased odds of readmission were associated with older age and the presence of congenital heart disease (0.86 [0.79-0.93], P < .001).

CONCLUSIONS

The pediatric pulmonary hypertension population carries significant morbidity, as reflected by a high use of intensive care unit resources and a high 30-day readmission rate. Younger patients and those with public insurance represent particularly at-risk groups.

Palivizumab prophylaxis for respiratory syncytial virus in infants with cystic fibrosis: is there a need?

Respiratory syncytial virus (RSV) infection in cystic fibrosis (CF) infants is associated with significant morbidities. This study's objective is to evaluate the effectiveness and adverse events related to palivizumab (PVZ) in CF infants. Data on respiratory-related illness (RIH) and RSV hospitalizations (RSVH) were collected retrospectively in CF infants aged < 2 years in Alberta, Canada, from 2000 to 2017. Logistic regression models were used to compare the odds of RSVH or RIH in PVZ infants from the Canadian registry of palivizumab (CARESS) versus untreated (UPVZ) infants from Alberta, after adjusting for potential confounders. Illness severity was compared between cohorts using χ² and t tests. A total of 267 CF infants were included: 183 (PVZ) and 84 (UPVZ). A total of 53.3% were tested for RSV. Fifty-five infants experienced a RIH and 10 had a RSVH. The PVZ cohort experienced similar odds of RSVH but decreased odds of RIH versus UPVZ, adjusting for gestational age, birth weight, birth during RSV peak months, and presence of siblings (Exp(B) = 0.23 [0.11-0.49], p < 0.0005). In RSVH-related subjects, PVZ subjects experienced shorter length of overall stay (LOS; t = 2.39 [df = 7], p = 0.048). In those with a RIH, the PVZ group had shorter overall intensive care unit (t = 3.52 [df = 15], p = 0.003) and hospital LOS (t = 2.11 [df = 52], p = 0.04). No serious adverse events were related to PVZ. The odds of RSVH were similar between groups, but PVZ subjects had decreased odds of RIH. The low number of RSV tests performed may explain the similarity in RSVH rates. Significant differences in LOS may indicate decreased RSVH and RIH illness severity in the PVZ versus UPVZ groups.

Past, Present and Future Approaches to the Prevention and Treatment of Respiratory Syncytial Virus Infection in Children

INTRODUCTION

The REGAL (RSV Evidence - A Geographical Archive of the Literature) series has provided a comprehensive review of the published evidence in the field of respiratory syncytial virus (RSV) in Western countries over the last 20 years. This seventh and final publication covers the past, present and future approaches to the prevention and treatment of RSV infection among infants and children.

METHODS

A systematic review was undertaken of publications between January 1, 1995 and December 31, 2017 across PubMed, Embase and The Cochrane Library. Studies reporting data on the effectiveness and tolerability of prophylactic and therapeutic agents for RSV infection were included. Study quality and strength of evidence (SOE) were graded using recognized criteria. A further nonsystematic search of the published literature and Clinicaltrials.gov on antiviral therapies and RSV vaccines currently in development was also undertaken.

RESULTS

The systematic review identified 1441 studies of which 161 were included. Management of RSV remains centered around prophylaxis with the monoclonal antibody palivizumab, which has proven effective in reducing RSV hospitalization (RSVH) in preterm infants < 36 weeks' gestational age (72% reduction), children with bronchopulmonary dysplasia (65% reduction), and infants with hemodynamically significant congenital heart disease (53% reduction) (high SOE). Palivizumab has also shown to be effective in reducing recurrent wheezing following RSVH (high SOE). Treatment of RSV with ribavirin has conflicting success (moderate SOE). Antibodies with increased potency and extended half-life are currently entering phase 3 trials. There are approximately 15 RSV vaccines in clinical development targeting the infant directly or indirectly via the mother.

CONCLUSION

Palivizumab remains the only product licensed for RSV prophylaxis, and only available for high-risk infants. For the general population, there are several promising vaccines and monoclonal antibodies in various stages of clinical development, with the aim to significantly reduce the global healthcare impact of this common viral infection.

FUNDING

AbbVie.