HARVARD MEDICAL SCHOOL 
PETER BENT BRIGHAM HOSPITAL 
Bernard N. Fields, M.D. 
Professor of Microbiology 
and Molecular Genetics 
Harvard Medical School 
25 Shattuc\ Street 
Boston, Massachusetts 02115 
(617) 734-7061 
Physician 
Chief, Infectious Disease Division 
Peter Bent Brigham Hospital 
December 13, 1979 
Dr. Don Fredrickson 
Director 
NIH 
Bethesda, Maryland 20205 
Dear Dr. Fredrickson: 
I would like to strongly support the revised guidelines 
as published in the Federal Register on November 30, 1979. 
In particular I specifically endorse the revision of the 
guidelines concerning the K-12 containment (section III-O). 
The proposals are a reasonable way of matching the realistic 
risks with the clear benefit of removing unnecessary ad- 
ministrative work. I hope you will support the new clas- 
sification. 
Sincerely, 
Bernard N. Fields, M.'D. 
BNF/lm 
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