Newcastle disease virus: is an updated attenuated vaccine needed?

Newcastle disease virus (NDV) is a major cause of infectious mortality and morbidity in poultry worldwide. It is an enveloped virus with two outer-membrane proteins-haemagglutinin-neuraminidase (HN) and fusion protein (F)-that induce neutralizing antibodies. All NDV strains belong to one serotype.

Pair-epitopes vaccination: enabling offspring vaccination in the presence of maternal antibodies.

Maternally derived antibodies (MDAs) are critical for offspring protection during the first days of life. However, due to their short half-life (3-5 days), MDA levels decline rapidly and by 8-15 days post-hatch drop to below protective levels. In addition, MDAs against a specific pathogen often impede the efficient protective immune response to that pathogen by the new-born following vaccination.