scholarly journals Live-Attenuated Respiratory Syncytial Virus Vaccine With M2-2 Deletion and With Small Hydrophobic Noncoding Region Is Highly Immunogenic in Children

2020 ◽  
Vol 221 (12) ◽  
pp. 2050-2059 ◽  
Author(s):  
Elizabeth J McFarland ◽  
Ruth A Karron ◽  
Petronella Muresan ◽  
Coleen K Cunningham ◽  
Charlotte Perlowski ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Neutralizing Antibodies ◽  
Phase 1 ◽  
Regulatory Protein ◽  
Neutralizing Antibody ◽  
Respiratory Illness ◽  
Antibody Responses ◽  
Upper Respiratory Tract ◽  
Syncytial Virus ◽  
Placebo Recipients

Abstract Background Respiratory syncytial virus (RSV) is the leading viral cause of severe pediatric respiratory illness, and vaccines are needed. Live RSV vaccine D46/NS2/N/ΔM2-2-HindIII, attenuated by deletion of the RSV RNA regulatory protein M2-2, is based on previous candidate LID/ΔM2-2 but incorporates prominent differences from MEDI/ΔM2-2, which was more restricted in replication in phase 1. Methods RSV-seronegative children aged 6–24 months received 1 intranasal dose (105 plaque-forming units [PFUs] of D46/NS2/N/ΔM2-2-HindIII [n = 21] or placebo [n = 11]) and were monitored for vaccine shedding, reactogenicity, RSV-antibody responses and RSV-associated medically attended acute respiratory illness (RSV-MAARI) and antibody responses during the following RSV season. Results All 21 vaccinees were infected with vaccine; 20 (95%) shed vaccine (median peak titer, 3.5 log10 PFUs/mL with immunoplaque assay and 6.1 log10 copies/mL with polymerase chain reaction). Serum RSV-neutralizing antibodies and anti-RSV fusion immunoglobulin G increased ≥4-fold in 95% and 100% of vaccines, respectively. Mild upper respiratory tract symptoms and/or fever occurred in vaccinees (76%) and placebo recipients (18%). Over the RSV season, RSV-MAARI occurred in 2 vaccinees and 4 placebo recipients. Three vaccinees had ≥4-fold increases in serum RSV-neutralizing antibody titers after the RSV season without RSV-MAARI. Conclusions D46/NS2/N/ΔM2-2-HindIII had excellent infectivity and immunogenicity and primed vaccine recipients for anamnestic responses, encouraging further evaluation of this attenuation strategy. Clinical Trials Registration NCT03102034 and NCT03099291.

scholarly journals Live Respiratory Syncytial Virus Attenuated by M2-2 Deletion and Stabilized Temperature Sensitivity Mutation 1030s Is a Promising Vaccine Candidate in Children

2019 ◽  
Vol 221 (4) ◽  
pp. 534-543 ◽  
Author(s):  
Elizabeth J McFarland ◽  
Ruth A Karron ◽  
Petronella Muresan ◽  
Coleen K Cunningham ◽  
Jennifer Libous ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Temperature Sensitivity ◽  
Neutralizing Antibodies ◽  
Quantitative Polymerase Chain Reaction ◽  
Regulatory Protein ◽  
Serum Antibody ◽  
Respiratory Illness ◽  
Acid Synthesis ◽  
Antibody Titers ◽  
Syncytial Virus

Abstract Background The safety and immunogenicity of live respiratory syncytial virus (RSV) candidate vaccine, LID/ΔM2-2/1030s, with deletion of RSV ribonucleic acid synthesis regulatory protein M2-2 and genetically stabilized temperature-sensitivity mutation 1030s in the RSV polymerase protein was evaluated in RSV-seronegative children. Methods Respiratory syncytial virus-seronegative children ages 6–24 months received 1 intranasal dose of 105 plaque-forming units (PFU) of LID/ΔM2-2/1030s (n = 21) or placebo (n = 11). The RSV serum antibodies, vaccine shedding, and reactogenicity were assessed. During the following RSV season, medically attended acute respiratory illness (MAARI) and pre- and postsurveillance serum antibody titers were monitored. Results Eighty-five percent of vaccinees shed LID/ΔM2-2/1030s vaccine (median peak nasal wash titers: 3.1 log10 PFU/mL by immunoplaque assay; 5.1 log10 copies/mL by reverse-transcription quantitative polymerase chain reaction) and had ≥4-fold rise in serum-neutralizing antibodies. Respiratory symptoms and fever were common (60% vaccinees and 27% placebo recipients). One vaccinee had grade 2 wheezing with rhinovirus but without concurrent LID/ΔM2-2/1030s shedding. Five of 19 vaccinees had ≥4-fold increases in antibody titers postsurveillance without RSV-MAARI, indicating anamnestic responses without significant illness after infection with community-acquired RSV. Conclusions LID/ΔM2-2/1030s had excellent infectivity without evidence of genetic instability, induced durable immunity, and primed for anamnestic antibody responses, making it an attractive candidate for further evaluation.

scholarly journals Characterization of Pre-F-GCN4t, a Modified Human Respiratory Syncytial Virus Fusion Protein Stabilized in a Noncleaved Prefusion Conformation

2017 ◽  
Vol 91 (13) ◽  
Author(s):  
Normand Blais ◽  
Martin Gagné ◽  
Yoshitomo Hamuro ◽  
Patrick Rheault ◽  
Martine Boyer ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Antibody Response ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Human Respiratory Syncytial Virus ◽  
Vaccine Antigen ◽  
Significant Advance ◽  
F Protein ◽  
Syncytial Virus

ABSTRACT The human respiratory syncytial virus (hRSV) fusion (F) protein is considered a major target of the neutralizing antibody response to hRSV. This glycoprotein undergoes a major structural shift from the prefusion (pre-F) to the postfusion (post-F) state at the time of virus-host cell membrane fusion. Recent evidences suggest that the pre-F state is a superior target for neutralizing antibodies compared to the post-F state. Therefore, for vaccine purposes, we have designed and characterized a recombinant hRSV F protein, called Pre-F-GCN4t, stabilized in a pre-F conformation. To show that Pre-F-GCN4t does not switch to a post-F conformation, it was compared with a recombinant post-F molecule, called Post-F-XC. Pre-F-GCN4t was glycosylated and trimeric and displayed a conformational stability different from that of Post-F-XC, as shown by chemical denaturation. Electron microscopy analysis suggested that Pre-F-GCN4t adopts a lollipop-like structure. In contrast, Post-F-XC had a typical elongated conical shape. Hydrogen/deuterium exchange mass spectrometry demonstrated that the two molecules had common rigid folding core and dynamic regions and provided structural insight for their biophysical and biochemical properties and reactivity. Pre-F-GCN4t was shown to deplete hRSV-neutralizing antibodies from human serum more efficiently than Post-F-XC. Importantly, Pre-F-GCN4t was also shown to bind D25, a highly potent monoclonal antibody specific for the pre-F conformation. In conclusion, this construct presents several pre-F characteristics, does not switch to the post-F conformation, and presents antigenic features required for a protective neutralizing antibody response. Therefore, Pre-F-GCN4t can be considered a promising candidate vaccine antigen. IMPORTANCE Human respiratory syncytial virus (RSV) is a global leading cause of infant mortality and adult morbidity. The development of a safe and efficacious RSV vaccine remains an important goal. The RSV class I fusion (F) glycoprotein is considered one of the most promising vaccine candidates, and recent evidences suggest that the prefusion (pre-F) state is a superior target for neutralizing antibodies. Our study presents the physicochemical characterization of Pre-F-GCN4t, a molecule designed to be stabilized in the pre-F conformation. To confirm its pre-F conformation, Pre-F-GCN4t was analyzed in parallel with Post-F-XC, a molecule in the post-F conformation. Our results show that Pre-F-GCN4t presents characteristics of a stabilized pre-F conformation and support its use as an RSV vaccine antigen. Such an antigen may represent a significant advance in the development of an RSV vaccine.

scholarly journals 2855. Respiratory Syncytial Virus Neutralizing Antibodies in Cord Blood and Serum from Infants up to 2 Years of Age in a Multinational Prospective Study

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S74-S75
Author(s):  
Joseph B Domachowske ◽  
Veronique Bianco ◽  
Ana Ceballos ◽  
Luis Cousin ◽  
Ulises D’Andrea ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Cord Blood ◽  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Entire Cohort ◽  
Syncytial Virus ◽  
Tract Infections

Abstract Background Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infections (LRTI) during infancy worldwide. High cord blood (CB) concentrations of anti-RSV neutralizing antibody (nAb) may attenuate, delay, or prevent infant infection. We report RSV A and B nAb concentrations in CB and serum from a birth cohort at different time points through 2 years of age. Methods Between 2013 and 2017, newborns from 8 countries were studied prospectively from birth to 2 years of age (NCT01995175). CB was collected at birth for the entire cohort. A subcohort of children was randomly assigned to have one blood sample collected again at either 2, 4, 6, 12, 18, or 24 months of age. Sera were analyzed for RSV A and B nAb concentrations by serum neutralization assay. Active surveillance was used to identify LRTIs during the 2-year follow-up as previously reported. Results In total, 2,401 newborns were enrolled and followed up. >99% of infants had detectable CB RSV A and B nAb. Geometric mean antibody titers (GMTs) varied by country, but were overall higher for RSV B than for RSV A (327 vs. 251; Figure 1). The lowest GMTs were seen from CB sera collected from South African newborns (197 RSV A, 255 RSV B); Canadian newborns had the highest RSV A GMT (383), while Hondurans had the highest RSV B GMT (460). 1380 infants provided follow-up serum nAb results as part of the subcohort (Figure 2). Dramatic waning of GMTs was evident, with a ~3-fold drop in GMTs at 2 months of age, and an additional ~2-fold drop between 2 and 4 months of age. At 6 and 12 months of age, 71% and 50% of infants had RSV A nAb and GMTs were at a nadir of 14. At 6, 12, and 18 months of age, RSV B nAb was detected in 98%, 69%, and 63% of infants, respectively. The RSV B nAb nadir GMT of 20 was observed at 12 months of age, while the 6- and 18-month RSV B nAb GMTs were 30 and 31, respectively. A total of 1,017 LRTIs were identified during the 2-year study period; of which, 94 (9%) were caused by RSV A and 132 (13%) by RSV B. Associations between CB nAb levels and RSV infection will be presented. Conclusion Neutralizing Ab to RSV A and B was present at birth in infants from 8 countries, and waned over time. GMTs were at a nadir at 6 to 12 months of age. Funding. GlaxoSmithKline Biologicals SA. Disclosures All Authors: No reported Disclosures.

scholarly journals Immunogenicity and Safety of 3 Formulations of a Respiratory Syncytial Virus Candidate Vaccine in Nonpregnant Women: A Phase 2, Randomized Trial

2019 ◽  
Vol 220 (11) ◽  
pp. 1816-1825 ◽  
Author(s):  
Tino F Schwarz ◽  
Roderick A McPhee ◽  
Odile Launay ◽  
Geert Leroux-Roels ◽  
Jaak Talli ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Neutralizing Antibody ◽  
Candidate Vaccine ◽  
Phase 2 ◽  
Serious Adverse Events ◽  
Intramuscular Dose ◽  
Syncytial Virus ◽  
Neonates And Infants

Abstract Background Respiratory syncytial virus (RSV) is a common cause of respiratory tract illness and hospitalization in neonates and infants. RSV vaccination during pregnancy may protect offspring in their first months of life. Methods This randomized, observer-blind, multicenter, phase 2 study evaluated the immunogenicity and safety of an RSV candidate vaccine in healthy nonpregnant women aged 18–45 years. Four hundred participants were randomized (1:1:1:1) to receive a single intramuscular dose of vaccine containing 30 µg, 60 µg, or 120 µg of RSV fusion protein engineered to preferentially maintain a prefusion conformation (RSV-PreF vaccine) or placebo. Results Thirty days postvaccination, RSV-A neutralizing antibody geometric mean titers (GMTs) increased 3.75-, 4.42- and 4.36-fold; RSV-B neutralizing antibody GMTs 2.36-, 2.54- and 2.76-fold; and palivizumab competing antibody (PCA) concentrations 11.69-, 14.38- and 14.24-fold compared with baseline levels in the 30 µg, 60 µg, and 120 µg RSV-PreF groups, respectively. Antibody titers and PCA concentrations at day 30 were significantly higher with the 120 µg compared to the 30 µg RSV-PreF vaccine. All RSV-PreF vaccine formulations and the placebo had similar reactogenicity profiles. No serious adverse events were considered to be related to the RSV-PreF vaccine. Conclusions The 3 formulations of the investigational RSV-PreF vaccine were well-tolerated and induced RSV-A and RSV-B neutralizing antibodies and PCAs in healthy, nonpregnant women. Clinical Trials Registration NCT02956837.

scholarly journals Structure of a Major Antigenic Site on the Respiratory Syncytial Virus Fusion Glycoprotein in Complex with Neutralizing Antibody 101F

2010 ◽  
Vol 84 (23) ◽  
pp. 12236-12244 ◽  
Author(s):  
Jason S. McLellan ◽  
Man Chen ◽  
Jung-San Chang ◽  
Yongping Yang ◽  
Albert Kim ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Neutralizing Antibodies ◽  
Antigenic Site ◽  
Neutralizing Antibody ◽  
Structural Basis ◽  
Effective Vaccine ◽  
Linear Epitope ◽  
Peptide Epitope ◽  
Fusion Glycoprotein ◽  
Syncytial Virus

ABSTRACT Respiratory syncytial virus (RSV) is a major cause of pneumonia and bronchiolitis in infants and elderly people. Currently there is no effective vaccine against RSV, but passive prophylaxis with neutralizing antibodies reduces hospitalizations. To investigate the mechanism of antibody-mediated RSV neutralization, we undertook structure-function studies of monoclonal antibody 101F, which binds a linear epitope in the RSV fusion glycoprotein. Crystal structures of the 101F antigen-binding fragment in complex with peptides from the fusion glycoprotein defined both the extent of the linear epitope and the interactions of residues that are mutated in antibody escape variants. The structure allowed for modeling of 101F in complex with trimers of the fusion glycoprotein, and the resulting models suggested that 101F may contact additional surfaces located outside the linear epitope. This hypothesis was supported by surface plasmon resonance experiments that demonstrated 101F bound the peptide epitope ∼16,000-fold more weakly than the fusion glycoprotein. The modeling also showed no substantial clashes between 101F and the fusion glycoprotein in either the pre- or postfusion state, and cell-based assays indicated that 101F neutralization was not associated with blocking virus attachment. Collectively, these results provide a structural basis for RSV neutralization by antibodies that target a major antigenic site on the fusion glycoprotein.

scholarly journals Removal of the N-Glycosylation Sequon at Position N116 Located in p27 of the Respiratory Syncytial Virus Fusion Protein Elicits Enhanced Antibody Responses after DNA Immunization

Viruses ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 426 ◽  
Author(s):  
Annelies Leemans ◽  
Marlies Boeren ◽  
Winke Van der Gucht ◽  
Isabel Pintelon ◽  
Kenny Roose ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Natural Infection ◽  
Antibody Responses ◽  
F Protein ◽  
Glycosylation Sites ◽  
Potential Vaccine ◽  
Syncytial Virus ◽  
Tract Infections

Prevention of severe lower respiratory tract infections in infants caused by the human respiratory syncytial virus (hRSV) remains a major public health priority. Currently, the major focus of vaccine development relies on the RSV fusion (F) protein since it is the main target protein for neutralizing antibodies induced by natural infection. The protein conserves 5 N-glycosylation sites, two of which are located in the F2 subunit (N27 and N70), one in the F1 subunit (N500) and two in the p27 peptide (N116 and N126). To study the influence of the loss of one or more N-glycosylation sites on RSV F immunogenicity, BALB/c mice were immunized with plasmids encoding RSV F glycomutants. In comparison with F WT DNA immunized mice, higher neutralizing titres were observed following immunization with F N116Q. Moreover, RSV A2-K-line19F challenge of mice that had been immunized with mutant F N116Q DNA was associated with lower RSV RNA levels compared with those in challenged WT F DNA immunized animals. Since p27 is assumed to be post-translationally released after cleavage and thus not present on the mature RSV F protein, it remains to be elucidated how deletion of this glycan can contribute to enhanced antibody responses and protection upon challenge. These findings provide new insights to improve the immunogenicity of RSV F in potential vaccine candidates.

scholarly journals Induction of Potent Neutralizing Antibody Responses by a Designed Protein Nanoparticle Vaccine for Respiratory Syncytial Virus

Cell ◽  
2019 ◽  
Vol 176 (6) ◽  
pp. 1420-1431.e17 ◽  
Author(s):  
Jessica Marcandalli ◽  
Brooke Fiala ◽  
Sebastian Ols ◽  
Michela Perotti ◽  
Willem de van der Schueren ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Syncytial Virus

scholarly journals Mucosal Immunization with Live Recombinant Bovine Respiratory Syncytial Virus (BRSV) and Recombinant BRSV Lacking the Envelope Glycoprotein G Protects against Challenge with Wild-Type BRSV

2002 ◽  
Vol 76 (23) ◽  
pp. 12355-12359 ◽  
Author(s):  
Ulrike Schmidt ◽  
Jörg Beyer ◽  
Ulf Polster ◽  
Laurel J. Gershwin ◽  
Ursula J. Buchholz
Keyword(s):  
Respiratory Syncytial Virus ◽  
Neutralizing Antibodies ◽  
Protective Efficacy ◽  
Bovine Respiratory Syncytial Virus ◽  
Upper Respiratory Tract ◽  
Mucosal Immunization ◽  
Recombinant Viruses ◽  
Glycoprotein G ◽  
Upper Respiratory ◽  
Syncytial Virus

ABSTRACT Recombinant bovine respiratory syncytial virus (rBRSV) and an rBRSV deletion mutant lacking the G gene (rBRSVΔG) were characterized in calves with respect to replication competence, attenuation, and protective efficacy as live-attenuated BRSV vaccines. Both recombinant viruses were safe and induced protection against a BRSV challenge infection. rBRSV replicated efficiently in the upper respiratory tract. Intranasal immunization with rBRSVΔG led to infection but not to mucosal virus replication. Neutralizing antibodies were induced by rBRSV and rBRSVΔG. Thus, the BRSV attachment glycoprotein G seems to be dispensable in vaccinating calves against BRSV.

scholarly journals Murine Immune Responses to Virus-Like Particle-Associated Pre- and Postfusion Forms of the Respiratory Syncytial Virus F Protein

2015 ◽  
Vol 89 (13) ◽  
pp. 6835-6847 ◽  
Author(s):  
Lori McGinnes Cullen ◽  
Madelyn R. Schmidt ◽  
Sarah A. Kenward ◽  
Robert T. Woodland ◽  
Trudy G. Morrison
Keyword(s):  
Respiratory Syncytial Virus ◽  
Neutralizing Antibodies ◽  
Vaccine Candidate ◽  
Neutralizing Antibody ◽  
Enzyme Linked Immunosorbent Assay ◽  
Chimeric Proteins ◽  
Wild Type ◽  
F Protein ◽  
Core Proteins ◽  
Syncytial Virus

ABSTRACTVirus-like particles (VLPs) built on the Newcastle disease virus (NDV) core proteins, NP and M, and containing two chimeric proteins, F/F and H/G, composed of respiratory syncytial virus (RSV) fusion protein (F) and glycoprotein (G) ectodomains fused to the transmembrane and cytoplasmic domains of the NDV F and HN proteins, respectively, stimulate durable, protective RSV neutralizing antibodies in mice. Here, we report the properties of VLPs constructed to contain mutant RSV F protein ectodomains stabilized in prefusion (pre-F/F) or postfusion (post-F/F) configurations. The structures of the chimeric proteins assembled into VLPs were verified immunologically by their reactivities with a conformationally restricted anti-F protein monoclonal antibody. Following immunization of mice, without adjuvant, pre-F/F-containing VLPs induced significantly higher neutralizing antibody titers than the post-F/F-containing VLPs or the wild-type F/F-containing VLPs after a single immunization but not after prime and boost immunization. The specificities of anti-F IgG induced by the two mutant VLPs were assessed by enzyme-linked immunosorbent assay (ELISA) using soluble forms of the prefusion and postfusion forms of the F protein as targets. While both types of VLPs stimulated similar levels of IgG specific for the soluble postfusion F protein, titers of IgG specific for prefusion F induced by the pre-F/F-containing VLPs were higher than those induced by post-F/F-containing VLPs. Thus, VLPs containing a stabilized prefusion form of the RSV F protein represent a promising RSV vaccine candidate.IMPORTANCEThe development of vaccines for respiratory syncytial virus has been hampered by a lack of understanding of the requirements for eliciting high titers of neutralizing antibodies. The results of this study suggest that particle-associated RSV F protein containing mutations that stabilize the structure in a prefusion conformation may stimulate higher titers of protective antibodies than particles containing F protein in a wild-type or postfusion conformation. These findings indicate that the prefusion F protein assembled into VLPs has the potential to produce a successful RSV vaccine candidate.

scholarly journals Review on bovine respiratory syncytial virus and bovine parainfluenza – usual suspects in bovine respiratory disease – a narrative review

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Birgit Makoschey ◽  
Anna Catharina Berge
Keyword(s):  
Respiratory Syncytial Virus ◽  
Respiratory Disease ◽  
Neutralizing Antibodies ◽  
Acute Infection ◽  
Bovine Respiratory Disease ◽  
Bovine Respiratory Syncytial Virus ◽  
Economic Losses ◽  
Cell Mediated Immunity ◽  
Upper Respiratory Tract ◽  
Syncytial Virus

AbstractBovine Respiratory Syncytial virus (BRSV) and Bovine Parainfluenza 3 virus (BPIV3) are closely related viruses involved in and both important pathogens within bovine respiratory disease (BRD), a major cause of morbidity with economic losses in cattle populations around the world. The two viruses share characteristics such as morphology and replication strategy with each other and with their counterparts in humans, HRSV and HPIV3. Therefore, BRSV and BPIV3 infections in cattle are considered useful animal models for HRSV and HPIV3 infections in humans.The interaction between the viruses and the different branches of the host’s immune system is rather complex. Neutralizing antibodies seem to be a correlate of protection against severe disease, and cell-mediated immunity is thought to be essential for virus clearance following acute infection. On the other hand, the host’s immune response considerably contributes to the tissue damage in the upper respiratory tract.BRSV and BPIV3 also have similar pathobiological and epidemiological features. Therefore, combination vaccines against both viruses are very common and a variety of traditional live attenuated and inactivated BRSV and BPIV3 vaccines are commercially available.

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