Human parvovirus, genus Bocavirus, associated with respiratory tract infections in children. Nucleic acid and polypeptide sequences of the virus. Methods and products for diagnosing presence of bocavirus in a sample using nucleic acid probes or primers, or specific binding members such as antibodies. Methods and products for diagnosing past or present infection of bocavirus in an individual e.g. by serology testing. Viral nucleic acid, polypeptide and/or viral particles for generating immune response in an individual, including vaccine compositions.