April 24, 1985

M. Essex, D.V.M., Ph.D., Chairman
Department of Cancer Biology
tiarvard School of Public Health
665 Huntington Avenue
Boston, MA 02115

Dear Max:

Thank you for your letter concerning the nomenclature proposals
to be made by the Retrovirus Study Group of the ICTV. This is an
area of great interest and the naming of human retroviruses has
obvious significance to individuals who work in the field.
Having been associated with Joe Melnick's tenure as chairman of
tho ICTV and an active personal participant in both parvovirus
and retrovirus nomenclature and classification, I have a general
suggestion to ease problems with the full ICTV. It is very
impcrtant that a committee appear to be international in make-up
- or to be designated as American and proceed down that path. In
this context, consideration should be given to Montagnier and
Weiss as full members. I also would add 1-2 Japanese in
accordance with what wil I follow below.

--

I object to the committee being labelled for "Pathogenic"
retroviruses. If Harold's intent is to attempt resolution of the
definition of HTLV-I and HTLV-Ill viruses as his letter
indicates, then the committee should be labelled for that
purpose. Otherwise what does one do about HTLV-I I and what about
the human spumaviruses? Attempting to accomplish too much wi i I
engender problems in areas where there is far too little data.

With regard to HTLV-I, the committee in my ."pinion, shalild
proceed. There is a concensus among workers. There is
uncontested genealogy and clear historical precedent. My major
point is that Roman numerals are inappropriate, thus it should bt
ti7LV-1. I have ac,.usad Bob Gal lo of chauvinisrri in using Rorir.,n
numerals instead of the conventional Arabic. i:!rthor, I would
recommend that the committee avoid saying anything at prcsent
about HTLV-2. The issues of what constitdtes d type wi I! rlot be
defined in the immediate future. The current bias as I perceive
it is that there is an HTLV-2, however, there is too little hard
data in my opinion to warrant a separate type designation at
present. I also fail to see any compel I ing reason to proceed to
address the question of what constitutes a species. See also
Harold's letter on this point and David Kingbury's suggestions.

As to the question of the HTLV-I I I/LAV aka ARV, there are some
major problems. Without writing a book on the issues, my recom-
mendation is to defer the question of what to name the virus.The
best argument is toagreeon a name that il would improve
communication. 1 f by chance the committee could unan~mously
agree on a name, then it would make a great contribution. The
basis for that name however should be predicated on the
consideration that there are likely to be new findings in the
next 1-2 years. If the committee can not easily agree, then
workers in the field will simply continue to use whatever
designations they choose. For the record, I am convince# that
with time, the issue of what to call HTLV-III/LAV will be
resolved spontaneously and that the committee's work will then be
much ea$ i er.

I happen to agree with many of Harold's sentiments about the
classification of retroviruses. Tho inadoquacies are, ds he
suggests, high1 ighted by the putative relationship of HTLV-
I1 I/LAV with lentiviruses. The current h~herrnt? of retrovirus
classif ;cation has an interesting history dnd needs revision, btlt
at the time we developed it it was an enormous improvement. The
challenge to the Retrovirus Siudy Group will be to lcarn and
apply standard rules of noaenclaturo and clnssificafion and to
not repoat or perpetuate past mistakes or inadequacies. Good
luck.

Incidentally, if the committee does elect to address issues of
HTLV-2 speciation, reclassification of retroviruses or novel
names for HTLV-III/LAV, I would greatly appreciate another
opportunity to comment.

Sincerely,

Wads P, Parks, Ph.D., M.D.
Professor of Pediatrics,
M i c r o b i o I o g y  8  I mm u n o I o g y

CC: Harold Varmus

Robert Gal lo

WPP:pc