Current interest in poxviruses centers around their possible use as vaccine vectors. The entire particle is enclosed in an envelope derived from the host cell membranes.
Most poxviruses are host-species specific, but vaccinia is a remarkable exception.
True pox viruses are antigenically rather similar, so that infection by one elicits immune protection against the others. Laboratory diagnosis of pox viruses may be undertaken by electron microscopy of negatively stained vesicle fluid or lesion material. In man it causes a localised pustule with scar formation. In immunocompromised persons or eczematous persons it sometimes caused a severe generalised vaccinia infection. Routine immunisation of all children in RSA stopped in about mid 1980's .