PROPOsEs THAT IT WOULD BE MORE REASONABLE EITHER TO CONSIDER 
EXPERIMENTS WITH VIRAL DNA ON A CASE BY CASE BASIS OR TO PRODUCE 
A DETAILED ss.T OF RECOMMENDED CATEGORIES FOR EXPERIMENTS WITH 
SPECIFIC VIRAL DNAs • SINCE THE LATTER IS BEYOND ITS COMPETENCE 
THE EMBO COMMITTEE HOPES IN THE NEAR FUTURE TO ESTABLISH AN 
AD HOC INTERNATIONAL GROUP OF VIROLOGISTS TO DRAW UP SUCH PROQOSALS. 
ViRUsc.s As VECTORS 
IN EXPERIMENTS INVOLVING THE INTRODUCTION OF FOREIGN DNA INTO 
CULTURED Cc.LLs OF ANIMALS USING DNA VIRUSES AS VECTORS* 
BIOLOGICAL CONTAINMENT IS ASSURED BY THE VERY RESTRICTED PERMISSIVE 
CONDITIONS FOR THE HOsT CELLS* THE ONLY ROUTES BY WHICH THE 
RECOMBINANT MOLECULE MIGHT ESCAPE ARE BY CHANCE INFECTION OF A 
CONTAMINATING MICROORGANISM OR WITHIN A VIRAL CAPSID AND THE SIZE 
OF THE RECOMBINANT MOLECULE MAY WELL PRECLUDE ITS ENCAPsI DATI ON. 
THE r,MBO COMMITTEE BELIEVEs THAT THE CATEGORIES OF PHYSICAL 
CONTAINMENT REQUIRED SHOULD DEPEND PRINCIPALLY UPON THE TAXONOMIC 
RELATIONSHIP BETWEEN THE DONOR OF THE DNA BEING CLONED AND THE 
NATURAL HOST SPECIES OF THE VECTOR VIRUS. 
A DETAILED SET OF CATEGORIES BASED UPON THE FOLLOWING PRINCIPLES 
Is CALLED FOR? 
DONOR DNA FROM A SPECIES THAT IS 
A HOsT FOR THE VECTOR - LOW LEVEL PHYSICAL CONTAINMENT 
[Appendix A — 94] 
