‘ 
The Joseph and Rose Kennedy 
Georgetown University 
Institute of Ethics 
Washington, D.C. 20057 
Center for Bioethics 
202/625-2371 
December 21, 1979 
Donald S. Fredrickson, M.D. 
Director 
National Institutes of Health 
Building One, Room 137 
Bethesda, MD 20014 
Dear Dr. Fredrickson: 
As a member of the NIH Recombinant DNA Advisory Committee, I am 
writing to express my strong support for the decision regarding research 
with coli K-12 host-vector systems which you announced in the Federal 
Register on November 30, 1979. 
In my view the decision which you reached is an entirely appropriate 
one. You clarified the recommendation of the Recombinant DNA Advisory 
Committee on one important point, namely, that the requirement of prior 
notification of local biosafety committees and of P-1 physical containment 
is different from an exemption. Second, the only area in which some 
members of the Recombinant Advisory Committee expressed any concern about 
research being conducted in Eh_ coli K-12 was that in some cases expression 
of biologically active hormones is sought. Your proposal would require 
prior review by the institutional biosafety committee before any such 
expression would in fact be undertaken. 
In addition, I think that it is worth noting that what looks like 
EK-1 biological containment is in fact now more than EK-1 containment in 
most cases involving E. coli K-12 hosts and vectors. Virtually all 
researchers use non-mobilizeable plasmas or lambda phage as vectors in 
their work with Eh_ coli K-12. These vectors provide a level of biological 
containment higher than that envisioned for EK-1 host-vector systems in 
the original 1976 guidelines. 
I strongly support your decision because I think that it will allow 
institutional biosafety committees to concentrate their primary emphasis 
on other areas of recombinant DNA research in which we as yet do not have 
the strong risk-assessment data which we now possess on research in 
E. coli K-12. 
Sincerely yours, 
LeRoy Walters, Ph.D. 
Director, Center for Bioethics 
Kennedy Institute 
LW:cwn 
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