The vaccine is being developed as a precaution, so it could be deployed quickly if the threat increases.
Trials are already under way, with volunteers receiving the experimental H5N1 vaccine at centres including a clinic in Southampton.
The UK Health Security Agency said the risk to the public remains low, with almost all human cases linked to close contact with infected animals.
Moore said there had been about 116 human cases worldwide in recent years.
He sought to reassure volunteers about safety, saying the vaccine had already been tested in earlier stages and that participants would be closely monitored throughout the study, with researchers collecting detailed data on their experiences.
