Background: Illness associated with Respiratory Syncytial Virus (RSV) remains an unmet medical need in both full-term infants and older adults. The fusion glycoprotein (F) of RSV, which plays a key role in RSV infection and is a target of neutralizing antibodies, is an attractive vaccine target for inducing RSV-specific immunity.
Methodology And Principal Findings: BALB/c mice and cotton rats, two well-characterized rodent models of RSV infection, were used to evaluate the immunogenicity of intramuscularly administered RSV vaccine candidates consisting of purified soluble F (sF) protein formulated with TLR4 agonist glucopyranosyl lipid A (GLA), stable emulsion (SE), GLA-SE, or alum adjuvants.
MEDI-534 is a bivalent live attenuated vaccine candidate against human respiratory syncytial virus (hRSV) and human parainfluenza virus type 3 (hPIV3) that was previously shown to be immunogenic and to protect rodents and African green monkeys from wild-type (wt) hRSV challenge. We performed further preclinical evaluations to address the safety of MEDI-534 prior to human testing. MEDI-534 did not predispose rodents to enhanced RSV disease following wt-RSV challenge, and the tissue tropism of the chimeric virus was confined to the respiratory tract.
View Article and Find Full Text PDFBackground: Human metapneumovirus (hMPV) infection can cause acute lower respiratory tract illness in infants, the immunocompromised, and the elderly. Currently there are no licensed preventative measures for hMPV infections. Using a variant of hMPV/NL/1/00 that does not require trypsin supplementation for growth in tissue culture, we deleted the M2-2 gene and evaluated the replication of rhMPV/DeltaM2-2 virus in vitro and in vivo.
View Article and Find Full Text PDFHuman metapneumovirus (hMPV) is a recently described member of the Paramyxoviridae family/Pneumovirinae subfamily and shares many common features with respiratory syncytial virus (RSV), another member of the same subfamily. hMPV causes respiratory tract illnesses that, similar to human RSV, occur predominantly during the winter months and have symptoms that range from mild to severe cough, bronchiolitis, and pneumonia. Like RSV, the hMPV virus can be subdivided into two genetic subgroups, A and B.
View Article and Find Full Text PDFHuman metapneumovirus (hMPV) infection causes respiratory tract disease similar to that observed during human respiratory syncytial virus infection (hRSV). hMPV infections have been reported across the entire age spectrum although the most severe disease occurs in young children. No vaccines, chemotherapeutics or antibodies are presently available for preventing or treating hMPV infections.
View Article and Find Full Text PDFRespiratory syncytial virus (RSV) causes respiratory disease in young children, the elderly, and immunocompromised individuals, often resulting in hospitalization and/or death. After more than 40 years of research, a Food and Drug Administration-approved vaccine for RSV is still not available. In this study, a chimeric bovine/human (b/h) parainfluenza virus type 3 (PIV3) expressing the human PIV3 (hPIV3) fusion (F) and hemagglutinin-neuraminidase (HN) proteins from an otherwise bovine PIV3 (bPIV3) genome was employed as a vector for RSV antigen expression with the aim of generating novel RSV vaccines.
View Article and Find Full Text PDFHuman metapneumovirus (hMPV), a recently identified paramyxovirus, is the causative agent of respiratory tract disease in young children. Epidemiological studies have established the presence of hMPV in retrospective as well as current clinical samples in Europe, USA, Canada, Hong Kong and Australia. The hMPV disease incidence rate varied from 7 to 12 %.
View Article and Find Full Text PDFRestricted replication in the respiratory tract of rhesus monkeys is an intrinsic property of bovine parainfluenza virus type 3 (bPIV-3) strains. This host range phenotype of bPIV-3 has been utilized as a marker to evaluate the attenuation of bPIV-3 vaccines for human use. Two safety, immunogenicity and efficacy studies in primates evaluated and compared three human parainfluenza virus type 3 (hPIV-3) vaccine candidates: biologically derived bPIV-3, a plasmid-derived bPIV-3 (r-bPIV-3) and a chimeric bovine/human PIV-3 (b/hPIV-3).
View Article and Find Full Text PDFA live attenuated bovine parainfluenza virus type 3 (PIV3), harboring the fusion (F) and hemagglutinin-neuraminidase (HN) genes of human PIV3, was used as a virus vector to express surface glycoproteins derived from two human pathogens, human metapneumovirus (hMPV) and respiratory syncytial virus (RSV). RSV and hMPV are both paramyxoviruses that cause respiratory disease in young children, the elderly, and immunocompromised individuals. RSV has been known for decades to cause acute lower respiratory tract infections in young children, which often result in hospitalization, while hMPV has only been recently identified as a novel human respiratory pathogen.
View Article and Find Full Text PDFParainfluenza virus type 3 (PIV3) and respiratory syncytial virus (RSV) are the main causes of ubiquitous acute respiratory diseases of infancy and early childhood, causing 20-25 % of pneumonia and 45-50 % of bronchiolitis in hospitalized children. The primary goal of this study was to create an effective and safe RSV vaccine based on utilizing attenuated bovine PIV3 (bPIV3) as a virus vector backbone. bPIV3 had been evaluated in human clinical trials and was shown to be attenuated and immunogenic in children as young as 2 months of age.
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