The kinetics of virus release from the apical chamber of HAE infected with the progeny virus of pIHBoV1 (cloned from the clinical Salvador1 isolate) was similar to that following infection with the HBoV1 Bonn1 isolate, a clinical specimen [31] . We believe that our study of HBoV1 infection of primary HAE reproduces infection of the virus from clinical specimens. In addition, we generated virus from a pIHBoV1-b clone, which contains the NSVP genes from the prototype HBoV1 st2 isolate [1] . Infection of primary B-HAE with this st2 virus resulted in a level of virus production similar to that observed here using the Salvador1 isolate (data not shown). We believe that our study with the laboratory-produced HBoV1 Salvador1 represents infection of HBoV1 of clinical specimens in HAE. The MOI used for infection in the current study was high. However, it should be noted that this titer is based on the physical numbers of virion particles as there are no practical methods for determining the infectious titer of HBoV1 preparations. It should also be taken into consideration that extensive parvovirus inactivation occurs during the purification process, i.e. during CsCl equilibrium ultracentrifugation [67] . Virus infection of HAE most likely reflects HBoV1 infection of the lung airways in patients with a high virus load in respiratory secretions [5] .