Anti-Metapneumovirus Monoclonal antibody

Human metapneumovirus (hMPV) is a common pathogen that can cause both upper and lower respiratory tract infections, particularly in children, elderly adults, and immunocompromised hosts. Since its initial identification in 2001, hMPV has been isolated from individuals with acute respiratory tract infections (ARTIs) in virtually every continent. Serological studies indicate that it has caused human infection since 1958 or earlier. The epidemiology and clinical manifestations of hMPV are similar to those of the human respiratory syncytial virus (hRSV). HMPV has a seasonal variation: it circulates in late winter to early spring in temperate climates; late spring and summer in tropical regions. In young children, symptoms range from mild upper respiratory tract infections to severe lower respiratory tract infections (eg, bronchiolitis, croup, and pneumonia). In adults, hMPV reinfection typically presents with colds and flulike clinical manifestations. The disease is more severe (sometimes lethal) in immunocompromised hosts. Reverse transcription polymerase chain reaction (RT-PCR) is the most sensitive test with which to detect hMPV infection. Direct detection of hMPV antigens with an immunofluorescent antibody test is available but is less sensitive than PCR. Antibody testing is used mainly for retrospective diagnosis (>= fourfold increase in titer or seroconversion) and for epidemiological studies. The mainstay of treatment of hMPV infections is supportive. Ribavirin has similar activity in vitro and in animal models against hRSV and hMPV, but its efficacy in vivo is unproven. Monoclonal antibodies have activity in murine models but are not available in humans. Several vaccines are promising in animal models, but their safety and efficacy have not yet been evaluated in humans.

The aim of this epidemiological study was to determine the prevalence of respiratory viruses, including new viruses, in hospitalised children in Austria. Two hundred fourteen nasopharyngeal samples from hospitalised children were tested for the presence of viruses using cell culture and PCR and/or viral antigen assays. The results revealed a parainfluenza virus 1 (PIV1) outbreak that ended right before the onset of the influenza season, with nearly no overlapping, moderate respiratory syncytial virus (RSV) activity, and only a few adenoviruses. Human metapneumovirus (hMPV) was present in 14.5% of the total samples but was detected in combination with other viruses in only five cases: with PIV1 in three cases and with RSV in two cases. There were no cases of dual infection with hMPV and flu or adenovirus. This suggests that hMPV alone is a leading cause of hospitalisation in children under 1 year of age. Interestingly, hMPV, in contrast to RSV, coincided with PIV1 but was absent during the community outbreak of the flu. Samples were also tested for Mimiviridae, a group of newly described DNA viruses that are similar to Legionella spp., replicate in water amoebae, and also have been found in alveolar cells. However, mimivirus was detected neither in respiratory samples nor in amoebaecontaining water samples, indicating that this particular type of virus is either not abundant or does not contribute to paediatric respiratory illnesses.