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Frontiers in Immunology 2023Nirsevimab is an extended half-life (M252Y/S254T/T256E [YTE]-modified) monoclonal antibody to the pre-fusion conformation of the respiratory syncytial virus (RSV) Fusion...
INTRODUCTION
Nirsevimab is an extended half-life (M252Y/S254T/T256E [YTE]-modified) monoclonal antibody to the pre-fusion conformation of the respiratory syncytial virus (RSV) Fusion protein, with established efficacy in preventing RSV-associated lower respiratory tract infection in infants for the duration of a typical RSV season. Previous studies suggest that nirsevimab confers protection via direct virus neutralization. Here we use preclinical models to explore whether fragment crystallizable (Fc)-mediated effector functions contribute to nirsevimab-mediated protection.
METHODS
Nirsevimab, MEDI8897* (i.e., nirsevimab without the YTE modification), and MEDI8897*-TM (i.e., MEDI8897* without Fc effector functions) binding to Fc γ receptors (FcγRs) was evaluated using surface plasmon resonance. Antibody-dependent neutrophil phagocytosis (ADNP), antibody-dependent cellular phagocytosis (ADCP), antibody-dependent complement deposition (ADCD), and antibody-dependent cellular cytotoxicity (ADCC) were assessed through and serological analyses. A cotton rat challenge study was performed with MEDI8897* and MEDI8897*-TM to explore whether Fc effector functions contribute to protection from RSV.
RESULTS
Nirsevimab and MEDI8897* exhibited binding to a range of FcγRs, with expected reductions in FcγR binding affinities observed for MEDI8897*-TM. Nirsevimab exhibited ADNP, ADCP, ADCD, and ADCC activity above background levels, and similar ADNP, ADCP, and ADCD activity to palivizumab. Nirsevimab administration increased ADNP, ADCP, and ADCD activity in participant serum from the MELODY study (NCT03979313). However, ADCC levels remained similar between nirsevimab and placebo. MEDI8897* and MEDI8897*-TM exhibited similar dose-dependent reduction in lung and nasal turbinate RSV titers in the cotton rat model.
CONCLUSION
Nirsevimab possesses Fc effector activity comparable with the current standard of care, palivizumab. However, despite possessing the capacity for Fc effector activity, data from RSV challenge experiments illustrate that nirsevimab-mediated protection is primarily dependent on direct virus neutralization.
Topics: Infant; Humans; Animals; Palivizumab; Antibodies, Viral; Respiratory Syncytial Virus, Human; Respiratory Syncytial Virus Infections; Complement System Proteins; Sigmodontinae
PubMed: 37901217
DOI: 10.3389/fimmu.2023.1283120 -
Antibodies (Basel, Switzerland) Sep 2023Respiratory Syncytial Virus (RSV) is a significant cause of lower respiratory tract infections in the young, the elderly, and in immunodeficient patients. As such, the...
Respiratory Syncytial Virus (RSV) is a significant cause of lower respiratory tract infections in the young, the elderly, and in immunodeficient patients. As such, the virus represents an important cause of morbidity and mortality worldwide. Development of monoclonal antibodies against RSV has resulted in a commercial prophylaxis, palivizumab (Synagis), and different antibodies that have improved our understanding of the structure of the viral proteins. In this study, a different immunization technique, subtractive immunization, was evaluated for its applicability to develop RSV-specific antibodies. One hybridoma which produced antibodies with the strongest staining of RSV infected cells, ATAC-0025, was selected for further characterization. This antibody belongs to the IgG1 class, has neutralizing capacity and recognizes the envelope F-protein. The antibody has a broad reactivity against a range of RSV reference strains and clinical isolates.
PubMed: 37873859
DOI: 10.3390/antib12040062 -
Frontiers in Public Health 2023Detection of community respiratory syncytial virus (RSV) infections informs the timing of immunoprophylaxis programs and hospital preparedness for surging pediatric...
INTRODUCTION
Detection of community respiratory syncytial virus (RSV) infections informs the timing of immunoprophylaxis programs and hospital preparedness for surging pediatric volumes. In many jurisdictions, this relies upon RSV clinical test positivity and hospitalization (RSVH) trends, which are lagging indicators. Wastewater-based surveillance (WBS) may be a novel strategy to accurately identify the start of the RSV season and guide immunoprophylaxis administration and hospital preparedness.
METHODS
We compared citywide wastewater samples and pediatric RSVH in Ottawa and Hamilton between August 1, 2022, and March 5, 2023. 24-h composite wastewater samples were collected daily and 5 days a week at the wastewater treatment facilities in Ottawa and Hamilton, Ontario, Canada, respectively. RSV WBS samples were analyzed in real-time for RSV by RT-qPCR.
RESULTS
RSV WBS measurements in both Ottawa and Hamilton showed a lead time of 12 days when comparing the WBS data set to pediatric RSVH data set (Spearman's ρ = 0.90). WBS identify early RSV community transmission and declared the start of the RSV season 36 and 12 days in advance of the provincial RSV season start (October 31) for the city of Ottawa and Hamilton, respectively. The differing RSV start dates in the two cities is likely associated with geographical and regional variation in the incidence of RSV between the cities.
DISCUSSION
Quantifying RSV in municipal wastewater forecasted a 12-day lead time of the pediatric RSVH surge and an earlier season start date compared to the provincial start date. These findings suggest an important role for RSV WBS to inform regional health system preparedness, reduce RSV burden, and understand variations in community-related illness as novel RSV vaccines and monoclonal antibodies become available.
Topics: Humans; Child; Palivizumab; Antiviral Agents; Ontario; Wastewater-Based Epidemiological Monitoring; Seasons; Cities; Wastewater; Respiratory Syncytial Virus, Human; Respiratory Syncytial Virus Infections
PubMed: 37829087
DOI: 10.3389/fpubh.2023.1261165 -
Human Vaccines & Immunotherapeutics Aug 2023Palivizumab has been shown to decrease RSV-related hospitalization (RSVH) risk and reduce RSVH severity. American Academy of Pediatrics (AAP) guidance on administration...
Palivizumab has been shown to decrease RSV-related hospitalization (RSVH) risk and reduce RSVH severity. American Academy of Pediatrics (AAP) guidance on administration of palivizumab has changed over time; in 2014, palivizumab was no longer recommended in preterm infants born at 29 weeks gestational age (wGA) or later. This study's objective was to describe RSVH risk and severity in preterm infants (29-34 wGA) without comorbidities relative to healthy term infants and to each other by gestational age. Using the MarketScan Multi-State Medicaid and Commercial Databases, infants born from July 1, 2014 to June 30, 2019, at 29-34 wGA (preterm) and >37 wGA (term) were identified. During RSV seasons (November to March) from 2014 to 2020, claims incurred by infants while they were <6 months old were evaluated for RSVH and RSVH characteristics. This study included 63,351 preterm infants and 1,076,389 term infants without outpatient palivizumab administration. Rate of RSVH was higher in infants with lower wGA at birth and ranged 3.32-5.72 per 100 infant-seasons in Medicaid-insured infants and 3.21-4.84 in commercially insured infants. Relative risk of RSVH was 5-8 times higher in Medicaid-insured preterm infants and 3-5 times higher in commercially insured preterm infants compared to term infants. ICU admissions and mechanical ventilation were more common during RSVH in preterm infants relative to term infants. RSV-related outpatient healthcare utilization was also 2-3 times higher in preterm infants born at 31-34 wGA. Increased utilization of palivizumab among infants born at 29-34 wGA may decrease RSVH rates and result in less severe course in preterm infants with RSVH.
Topics: Infant; Infant, Newborn; Humans; Child; United States; Palivizumab; Gestational Age; Infant, Premature; Antiviral Agents; Outpatients; Respiratory Syncytial Virus Infections; Hospitalization
PubMed: 37828711
DOI: 10.1080/21645515.2023.2252289 -
The Journal of Allergy and Clinical... Nov 2023Infants with respiratory-syncytial virus bronchiolitis hospitalization are more likely to develop wheezing and subsequent asthma. Reportedly, palivizumab prophylaxis...
BACKGROUND
Infants with respiratory-syncytial virus bronchiolitis hospitalization are more likely to develop wheezing and subsequent asthma. Reportedly, palivizumab prophylaxis effectively prevents respiratory-syncytial virus hospitalization in high-risk children-such as premature infants or infants with bronchopulmonary dysplasia (BPD).
OBJECTIVE
We sought to explore the effect of respiratory-syncytial virus immunoprophylaxis on the risk of asthma development in premature infants with BPD in subtropical areas.
METHODS
This case-control study included preterm children with BPD born at Mackay Memorial Hospital, Taipei, Taiwan, from 1999 to 2015. Overall, medical records of 616 eligible participants were retrospectively collected from their birth to the time they attained an age of 5 to 20 years. The primary outcome was onset of active asthma.
RESULTS
Overall, 576 consecutive cases met the inclusion criteria. Of these, 306 (53.2%) patients had palivizumab exposure and 191 (33.2%) were diagnosed with asthma. Patients with history of respiratory-syncytial virus bronchiolitis hospitalization had a higher risk of developing asthma in the future (adjusted odds ratio, 3.77; 95% CI, 2.30-6.20, < .001; hazard ratio, 2.56; 95% CI, 1.81-3.62, < .001). Palivizumab prophylaxis reduced future asthma development through the inhibition of respiratory-syncytial virus bronchiolitis hospitalization (coefficient, -0.021; 95% CI, -0.031 to -0.011, = .027). Asthmatic children who received palivizumab immunoprophylaxis had a lesser active asthma duration than those who did not ( = .005).
CONCLUSIONS
Children with BPD with hospitalization for respiratory-syncytial virus bronchiolitis had higher risk of developing asthma compared with those without respiratory-syncytial virus infection. Prophylactic palivizumab might reduce later asthma development through inhibition of respiratory-syncytial virus bronchiolitis hospitalization. For those already developing asthma, palivizumab could reduce active asthma duration.
PubMed: 37781666
DOI: 10.1016/j.jacig.2023.100161 -
Pediatrics and Neonatology Mar 2024Respiratory syncytial virus (RSV) hospitalizations have increased since the 2014 guideline update recommended against the use of palivizumab for preterm infants born...
BACKGROUND
Respiratory syncytial virus (RSV) hospitalizations have increased since the 2014 guideline update recommended against the use of palivizumab for preterm infants born ≥29 0/7 weeks' gestational age (GA) without additional risk factors. A novel drug candidate, nirsevimab, has been developed for this population. We analyzed the cost-effectiveness of palivizumab/nirsevimab vs. no prophylaxis in this population.
METHODS
A hybrid-Markov model predicted the RSV clinical course in the first year of life and sequelae in the subsequent four years for preterm infants from the healthcare and societal perspectives. Model parameters were derived from the literature. We calculated costs and quality-adjusted life-years (QALYs) to produce an incremental cost-effectiveness ratio (ICER) evaluated at a willingness-to-pay threshold of $150,000/QALY. Sensitivity analyses assessed model robustness. A threshold analysis examined nirsevimab pricing uncertainty.
RESULTS
Compared to no prophylaxis, palivizumab costs $9572 and $9584 more from the healthcare and societal perspectives, respectively, with 0.0019 QALYs gained per patient over five years, resulting in ICERs >$5 million per QALY from each perspective. Results were robust to parameter uncertainties; probabilistic sensitivity analysis revealed that no prophylaxis had a 100% probability of being cost-effective. The threshold analysis suggested that nirsevimab is not cost-effective when compared to no prophylaxis if the price exceeds $1962 from a societal perspective.
CONCLUSION
Palivizumab is dominated by no prophylaxis for preterm infants 29 0/7-34 6/7 weeks' GA with no additional risk factors. Relevant stakeholders should consider alternatives to palivizumab for this population that are both effective and economical.
Topics: Infant; Infant, Newborn; Humans; United States; Pregnancy; Female; Palivizumab; Infant, Premature; Cost-Benefit Analysis; Gestational Age; Antiviral Agents; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; Hospitalization; Antibodies, Monoclonal, Humanized
PubMed: 37758594
DOI: 10.1016/j.pedneo.2023.04.015 -
Anales de Pediatria Oct 2023Nirsevimab, a monoclonal antibody for the prevention of disease caused by respiratory syncytial virus (RSV), has recently been approved for use in Europe and Spain. (Review)
Review
INTRODUCTION
Nirsevimab, a monoclonal antibody for the prevention of disease caused by respiratory syncytial virus (RSV), has recently been approved for use in Europe and Spain.
OBJECTIVES
To provide recommendations for the administration of nirsevimab for prevention of RSV disease.
METHODS
The approach chosen to develop these recommendations involved a critical review of the literature and the use of the Delphi and GRADE methods. An expert group was formed. The group engaged in three rounds to define the questions, express support or opposition, grade recommendations and establish the agreement or disagreement with the conclusions.
RESULTS
In the general neonatal population, routine administration of nirsevimab is recommended to reduce the frequency of illness and hospitalisation for bronchiolitis and RSV lower respiratory tract infection. Nirsevimab is recommended for all infants born in high-incidence RSV season and infants aged less than 6 months at the season onset. In infants born preterm between 29 and 35 weeks of gestation, with haemodynamically significant heart disease or with chronic lung disease, routine administration of nirsevimab is recommended to reduce the incidence of disease and hospitalisation due to bronchiolitis and RSV lower respiratory tract infection. In patients in whom palivizumab is currently indicated, its substitution by nirsevimab is recommended to reduce the burden of bronchiolitis.
CONCLUSIONS
Routine administration of nirsevimab to all infants aged less than 6 months born during the RSV season or aged less than 6 months at the start of the winter season is recommended to reduce the burden of disease and the frequency of hospitalization due to bronchiolitis.
Topics: Infant, Newborn; Infant; Humans; Child; Antiviral Agents; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus, Human; Communicable Diseases; Respiratory Tract Infections; Bronchiolitis
PubMed: 37743207
DOI: 10.1016/j.anpede.2023.09.006 -
The Journal of Biological Chemistry Nov 2023Synthetic cytokine receptors can modulate cellular functions based on an artificial ligand to avoid off-target and/or unspecific effects. However, ligands that can...
Synthetic cytokine receptors can modulate cellular functions based on an artificial ligand to avoid off-target and/or unspecific effects. However, ligands that can modulate receptor activity so far have not been used clinically because of unknown toxicity and immunity against the ligands. Here, we developed a fully synthetic cytokine/cytokine receptor pair based on the antigen-binding domain of the respiratory syncytial virus-approved mAb Palivizumab as a synthetic cytokine and a set of anti-idiotype nanobodies (AIP) as synthetic receptors. Importantly, Palivizumab is neither cross-reactive with human proteins nor immunogenic. For the synthetic receptors, AIP were fused to the activating interleukin-6 cytokine receptor gp130 and the apoptosis-inducing receptor Fas. We found that the synthetic cytokine receptor AIPgp130 was efficiently activated by dimeric Palivizumab single-chain variable fragments. In summary, we created an in vitro nonimmunogenic full-synthetic cytokine/cytokine receptor pair as a proof of concept for future in vivo therapeutic strategies utilizing nonphysiological targets during immunotherapy.
Topics: Humans; Palivizumab; Receptors, Artificial; Receptors, Cytokine; Cytokines; Respiratory Syncytial Virus Infections; Ligands; Respiratory Syncytial Virus, Human; Antiviral Agents
PubMed: 37734558
DOI: 10.1016/j.jbc.2023.105270