MINUTES OF MEETING - March 6-7 
13 
The motion as passed by the RAC amends the Guidelines as follows: 
"III-C-1-e. All Viral Vectors. 
Ill-C-l-e-(l) . Other experiments involving eukaryotic viral 
vectors can be done as follows: 
III-C-l-e-(l)-(a) . Recombinant DNA molecules containing 
no mere than two- thirds of the gencme of any eukaryotic 
virus (all viruses from a single Family being considered 
identical) may be propagated and maintained in cells in 
tissue culture using PI containment. For such experiments, 
it must be shown that the cells lack helper virus for the 
specific Families of defective viruses being used. The DNA 
may contain fragments of the genomes of viruses from more 
than one Family but each fragment must be less than two- 
thirds of a gencme." 
During the discussion it was also suggested that in Section III-C-1-e- 
(l)-(a), after the word "Family," reference to footnote 36 be added, and 
that footnote 36 be revised to make reference to the third report of the 
International Committee on Taxonomy of Viruses. 
Dr. Gottesman began the discussion of parts two [preposed section III-C-1- 
e-(l)-(b)] and three [proposed section III-C-l-e-(l)-(c) ] of the proposal. 
They read as follows: 
"III-C-l-e-(l)-(b) . Recombinants with less than two-thirds 
of the genome of any eukaryotic virus may be rescued with 
helper virus using P2 containment if wild type strains 
of the helper virus are not able to grow in human cells. 
III-C-l-e-(l)-(c) . Recombinants with less than two-thirds 
of the genome of any eukaryotic virus may be rescued with 
helper virus using P3 containment if wild type strains of 
the helper virus are able to grow in human cells." 
Dr. Gottesman said that these sections pertain to experiments in which 
helper virus is added to cells in culture. She thought limited possibil- 
ity for transfer exists in these cases: If there were escape into environ- 
ment the helper and the recombinant defective virus would probably be 
diluted away from each other leading to a dead end for replication of 
the recombinant ENA. She noted that this proposal permits a generalized 
use of viral vectors beyond that which currently exist in the Guidelines. 
Dr. Baltimore noted that viruses of CDC Class 3, 4 or 5 could not be used 
as vectors because of Section I-D-l of the Guidelines. Dr. Gottesman said 
that a change in the status of Class 3 organisms will soon be considered 
by the RAC. Dr. Gottesman questioned whether this proposal should be 
restricted to CDC Class 1 etiological agents. 
[ 48 ] 
