Respiratory Syncytial Virus Genotypes, Host Immune Profiles, and Disease Severity in Young Children Hospitalized With Bronchiolitis.

Background: Data on how respiratory syncytial virus (RSV) genotypes influence disease severity and host immune responses is limited. Here, we characterized the genetic variability of RSV during 5 seasons, and evaluated the role of RSV subtypes, genotypes, and viral loads in disease severity and host transcriptional profiles.

Methods: A prospective, observational study was carried out, including a convenience sample of healthy infants hospitalized with RSV bronchiolitis.

Safety and immunogenicity of a live attenuated RSV vaccine in healthy RSV-seronegative children 5 to 24 months of age.

Unlabelled: Despite substantial morbidity associated with respiratory syncytial virus (RSV) infection, there is no licensed vaccine. MEDI-559 is a live attenuated intranasal vaccine candidate being developed for prevention of lower respiratory illness due to RSV in young children. This randomized, placebo-controlled study evaluated safety of MEDI-559 in healthy, RSV-seronegative children.

Implication of respiratory syncytial virus (RSV) F transgene sequence heterogeneity observed in Phase 1 evaluation of MEDI-534, a live attenuated parainfluenza type 3 vectored RSV vaccine.

MEDI-534 is the first live vectored RSV vaccine candidate to be evaluated in seronegative children. It consists of the bovine parainfluenza virus type 3 (PIV3) genome with substituted human PIV3 F and HN glycoproteins engineered to express RSV F protein. A Phase 1 study of 49 healthy RSV and PIV3 seronegative children 6 to <24 months of age demonstrated an acceptable safety profile at the following doses: 10(4), 10(5) and 10(6)TCID50.

Human metapneumovirus G protein is highly conserved within but not between genetic lineages.

Human metapneumovirus (HMPV) is an important cause of acute respiratory illnesses in children. HMPV encodes two major surface glycoproteins, fusion (F) and glycoprotein (G). The function of G has not been fully established, though it is dispensable for in vitro and in vivo replication.

Molecular and cellular response profiles induced by the TLR4 agonist-based adjuvant Glucopyranosyl Lipid A.

Background: Toll-like receptor (TLR)4 agonists are known potent immunostimulatory compounds. These compounds can be formulated as part of novel adjuvants to enhance vaccine medicated immune responses. However, the contribution of the formulation to the innate in vivo activity of TLR4 agonist compounds is not well understood.

Analysis of respiratory syncytial virus preclinical and clinical variants resistant to neutralization by monoclonal antibodies palivizumab and/or motavizumab.

Background: Palivizumab is a US Food and Drug Administration-approved monoclonal antibody for the prevention of respiratory syncytial virus (RSV) lower respiratory disease in high-risk infants. Motavizumab, derived from palivizumab with enhanced antiviral activity, has recently been tested in humans. Although palivizumab escape mutants have been generated in the laboratory, the development of resistant RSV in patients receiving palivizumab has not been reported previously.

The hemagglutinin protein of influenza A/Vietnam/1203/2004 (H5N1) contributes to hyperinduction of proinflammatory cytokines in human epithelial cells.

Live attenuated influenza A/Vietnam/1203/04 (H5N1) (VN04 cold adapted [ca]) and A/Hong Kong/213/03 (H5N1) (HK03 ca) vaccine viruses were compared with the A/New Caledonia/20/99 (H1N1) (NC99 ca) seasonal vaccine virus for induction of host gene expression in infected human epithelial cells. Levels of proinflammatory cytokines and interferon-related genes were significantly upregulated in VN04 ca virus-infected A549 cells compared to cells infected with the HK03 ca and NC99 ca viruses as examined by microarray analysis and confirmed by quantitative RT-PCR and ELISA assays. Further mapping studies demonstrated that the hemagglutinin (HA) protein of the VN04 ca virus contributed to the hyperinduction of cytokines.

Evaluation of replication and cross-reactive antibody responses of H2 subtype influenza viruses in mice and ferrets.

H2 influenza viruses have not circulated in humans since 1968, and therefore a large segment of the population would likely be susceptible to infection should H2 influenza viruses reemerge. The development of an H2 pandemic influenza virus vaccine candidate should therefore be considered a priority in pandemic influenza preparedness planning. We selected a group of geographically and temporally diverse wild-type H2 influenza viruses and evaluated the kinetics of replication and compared the ability of these viruses to induce a broadly cross-reactive antibody response in mice and ferrets.

Genetic sequence analysis of influenza viruses and illness severity in ill children previously vaccinated with live attenuated or inactivated influenza vaccine.

In a large comparative study in 2004-2005, children aged 6-59 months vaccinated with live attenuated influenza vaccine (LAIV) experienced 55% fewer cases of culture-confirmed influenza illness compared with trivalent inactivated influenza vaccine (TIV) recipients. To better understand the characteristics of the breakthrough influenza illnesses, we analyzed the HA1 genetic sequence for all available samples and examined disease severity by strain and treatment group. All 48 A/H1N1 viruses were well-matched to the vaccine, whereas all 276 A/H3N2 viruses and 349 (96%) influenza B viruses were mismatched to the vaccine.

Population-based incidence of human metapneumovirus infection among hospitalized children.

Background: Human metapneumovirus (HMPV) is a leading cause of acute respiratory illness (ARI) in children. Population-based incidence rates and comprehensive clinical characterizations of disease have not been established.

Methods: We conducted population-based prospective surveillance for 2 years in 2 US counties of HMPV infection among children <5 years old who were hospitalized with ARI or fever.

Genetic diversity and evolution of human metapneumovirus fusion protein over twenty years.

Background: Human metapneumovirus (HMPV) is an important cause of acute respiratory illness in children. We examined the diversity and molecular evolution of HMPV using 85 full-length F (fusion) gene sequences collected over a 20-year period.

Results: The F gene sequences fell into two major groups, each with two subgroups, which exhibited a mean of 96% identity by predicted amino acid sequences.

Avian influenza h6 viruses productively infect and cause illness in mice and ferrets.

Influenza pandemic preparedness has focused on influenza virus H5 and H7 subtypes. However, it is not possible to predict with certainty which subtype of avian influenza virus will cause the next pandemic, and it is prudent to include other avian influenza virus subtypes in pandemic preparedness efforts. An H6 influenza virus was identified as a potential progenitor of the H5N1 viruses that emerged in Hong Kong in 1997.

Cell type specificity of lung cancer associated with air pollution.

The aim of this study is to explore whether lung cancer associated with air pollution has cell type specificity. The air quality data (SO(2), CO, O(3), NOx) from the Taiwan EPA's air quality monitoring stations were collected between 1995 and 1998. Patients with lung cancer were identified through the National Cancer Registration Program operated by the Taiwanese government.

Genetic stability of live, cold-adapted influenza virus components of the FluMist/CAIV-T vaccine throughout the manufacturing process.

FluMist is a live-attenuated, trivalent influenza vaccine (LAIV) recently approved for intranasal administration. To demonstrate genetic stability during manufacture of the vaccine viruses in LAIV and a similar vaccine in development (CAIV-T), full genome consensus sequences were determined at multiple manufacturing stages for four influenza type A and five type B strains. The critical cold-adapted (ca), temperature-sensitive (ts) and attenuated (att) mutations were preserved in the virus manufacturing intermediates.

The role of human metapneumovirus in upper respiratory tract infections in children: a 20-year experience.

Background: The role that human metapneumovirus (hMPV) plays in the etiology of upper respiratory tract infections (URIs) in children over a period of many years has not been evaluated previously.

Methods: By use of real-time reverse-transcriptase polymerase chain reaction, we retrospectively tested nasal wash (NW) specimens for hMPV that had been obtained from a cohort of 1532 infants and children with URIs who were prospectively followed for an average of 2.4 years during the period from 1982 to 2001.

Chaperonin GroEL and its mutant D87K protect from ischemia in vivo and in vitro.

Protein aggregation and misfolding are central mechanisms of both acute and chronic neurodegeneration. Overexpression of chaperone Hsp70 protects from stroke in animal and cell culture models. Although it is accepted that chaperones protect cells, the mechanism of protection by chaperones in ischemic injury is poorly understood.

Multiple gene segments control the temperature sensitivity and attenuation phenotypes of ca B/Ann Arbor/1/66.

Cold-adapted (ca) B/Ann Arbor/1/66 is the influenza B virus strain master donor virus for FluMist, a live, attenuated, influenza virus vaccine licensed in 2003 in the United States. Each FluMist vaccine strain contains six gene segments of the master donor virus; these master donor gene segments control the vaccine's replication and attenuation. These gene segments also express characteristic biological traits in model systems.

Sensitivity of diagnostic tests for influenza varies with the circulating strains.

Background: Effective strategies to combat the spread of influenza viruses rely on accurate diagnosis of the infection, which is greatly affected by the sensitivity of the assays used.

Objectives: To determine if the sensitivity of assays used to detect influenza varies with the viral strains.

Study Design: This prospective study used 142 respiratory specimens submitted to the clinical virology laboratory during the 2003/2004 influenza season, when the H3N2 Fujian strain was first detected in our community, to assess sensitivities of rapid immunoassay (RIA), shell-vial (SV), hemadsorption (HA)-, and fluorescent antibody (FA)-based conventional tissue culture (TC).

Recovery of human metapneumovirus genetic lineages a and B from cloned cDNA.

Human metapneumovirus (hMPV) is a newly discovered pathogen associated with respiratory tract illness, primarily in young children, immunocompromised individuals, and the elderly. The genomic sequence of the prototype hMPV isolate NL/1/00 without the terminal leader and trailer sequences has been reported previously. Here we describe the leader and trailer sequences of two hMPV isolates, NL/1/00 and NL/1/99, representing the two main genetic lineages of hMPV.

Cross-reactive H1N1 antibody responses to a live attenuated influenza vaccine in children: implication for selection of vaccine strains.

Cross-reactive antibody responses of 3 trivalent, live attenuated intranasal influenza vaccine (FluMist) formulations containing 3 different H1N1 strains (A/Texas/36/91, A/Shenzhen/227/95, and A/Beijing/262/95) were evaluated in initially seronegative children. FluMist containing A/Shenzhen/227/95 was more likely to induce cross-reactive hemagglutination inhibition (HAI) antibody against A/Texas/36/91 than against A/Beijing/262/95, and FluMist containing A/Beijing/262/95 induced low levels of cross-reactive HAI antibody against A/Shenzhen/227/95 and A/New Caledonia/20/99. The observed differences in HAI cross-reactivity seem to be partly related to the number of amino acid (aa) differences on the hemagglutinin 1 domain (328 aa residues) rather than the hemagglutinin protein (550 aa residues).

Multiple amino acid residues confer temperature sensitivity to human influenza virus vaccine strains (FluMist) derived from cold-adapted A/Ann Arbor/6/60.

FluMist influenza A vaccine strains contain the PB1, PB2, PA, NP, M, and NS gene segments of ca A/AA/6/60, the master donor virus-A strain. These gene segments impart the characteristic cold-adapted (ca), attenuated (att), and temperature-sensitive (ts) phenotypes to the vaccine strains. A plasmid-based reverse genetics system was used to create a series of recombinant hybrids between the isogenic non-ts wt A/Ann Arbor/6/60 and MDV-A strains to characterize the genetic basis of the ts phenotype, a critical, genetically stable, biological trait that contributes to the attenuation and safety of FluMist vaccines.

Rescue of influenza B virus from eight plasmids.

Influenza B virus causes a significant amount of morbidity and mortality, yet the systems to produce high yield inactivated vaccines for these viruses have lagged behind the development of those for influenza A virus. We have established a plasmid-only reverse genetics system for the generation of recombinant influenza B virus that facilitates the generation of vaccine viruses without the need for time consuming coinfection and selection procedures currently required to produce reassortants. We cloned the eight viral cDNAs of influenza B/Yamanashi/166/98, which yields relatively high titers in embryonated chicken eggs, between RNA polymerase I and RNA polymerase II transcription units.