December 20, 1979 
Dr. Donald S. Fredrickson 
Director 
National Institutes of Health 
Bethesda, Maryland 20205 
Dear Dr. Fredrickson, 
As you know, I am a member of the Recombinant Advisory Committee 
who voted against the proposal to lower required containment for _E. 
coli K12 recombinant DNA experiments. During this additional comment 
period, questions have been raised about the procedures used by our 
committee when this proposal was approved. I would like to register 
my opinion on this matter. 
In my opinion, the RAC discussion was extensive and relevant. 
There was ample opportunity for expression of a variety of opinions, 
both at the September meeting and during the previous discussion at the 
May meeting. The voting procedures used by the committee were 
appropriate and i n accordance with HEW regulations. The vote as 
registered almost certainly reflects the judgement of the committee as 
a whole even though several members were absent. In the end, what we 
really differed about were the conclusions that we drew from the data; 
I suspect that no amount of future data, discussion or experience 
would make the committee unanimous on this issue. 
I voted against the proposal because I felt that the data on 
possible consequences of expression of a harmful product by an _E. coli 
containing recombinant DNA had not been fully explored, and that therefore 
P1-EK1 containment might not be assumed to be adequate in all cases. 
Members of our committee, each with access to the same data, came to 
different conclusions. The problem is not what the data shows but 
what the overall risk of Ji. coli experiments might be and how much 
risk is acceptable. The split vote of the RAC at least partially 
reflects this range of possible conclusions from the same data, and 
expresses the complexity of the problem more than anything else. This 
is as it should be: we are making our best guesses about unknown and 
speculative hazards, and we need the differences of opinion to insure 
that we think about everything. I do not think that such a split vote 
should be overinterpreted; the committee will become either totally 
unable to act at all or forced to a false unanimity if decisions are 
held up simply on the basis of split votes. 
I hope these comments will be helpful. 
Sincerely 
Susan Gottesman 
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