Newcastle disease virus as a vaccine vector for humans.

Emerging and re-emerging infectious diseases pose a threat to individuals worldwide and necessitate the development of new vaccines and vaccine platforms. Newcastle disease virus (NDV) is an enveloped cytoplasmic RNA virus of avian origin that is highly attenuated in humans and other primates because of a strong host-range restriction. NDV infects the respiratory tract of non-human primates and appears to remain restricted to that site. As a vaccine vector, NDV induced substantial local and systemic responses against a protein expressed by a foreign gene insert and was protective against pathogen challenge. NDV is antigenically distinct from common human viruses, accommodates foreign sequences with a good degree of stability, can be readily produced in a cell line acceptable for human product development, and exhibits a low incidence of recombination. Because of its natural tropism for the respiratory tract, NDV may be particularly effective for the development of vectored vaccines against respiratory infections as well as infections that can be transmitted through the respiratory tract.