The present invention relates to novel immunogenic polypeptides and their use in vaccine compositions. The invention also relates to nucleic acids, vectors and cells which express the polypeptides and the uses thereof. The polypeptides of the invention more specifically comprise an immunogenic domain and a cell membrane addressing domain which is derived from a B5R gene. The invention is particularly suited to produce vaccines for non-human animals, particularly for vaccinating swine against PCV2 infection.