HAS DUESBERG A RIGHT OF REPLY?
By John Maddox
Nature 13 May 1993
Dr Peter Duesberg, the virologistturnedcampaigner, is wrongly
using tendentious arguments to confuse understanding of AIDS and those
in danger of contracting the disease. He should stop.
What is to be thought of a science journal that publishes attacks on
the opinions of a scientist, but which never (or hardly ever) publishes
his replies? On the face of things, this is a serious breach of journalistic
ethics and it would be legally prevented by the legislation on the
press perpetually being considered by the British House of Commons. Yet
that is how Nature has behaved to Dr Peter Duesberg, the virologist
from Berkeley who is identified with the view that HIV does not cause AIDS.
How can such intolerance be justified?
What follows is an explanation. But first, an essential part of the
tale is that Duesberg is a molecular virologist of distinction; His last
major publication in Nature (304, 2 1 9; 1983) was a classic of
its kind. He is also a person of intelligence and good humour. Moreover,
there are elements in his position on the causation of AIDS that are not
nearly as perverse as they are often represented.
Early on, Duesberg raised some cogent questions. For example, why, if
HIV is an infectious agent and also the cause of AIDS is it so difficult
to recover virus from the particular T cells (CD4 cells) that are supposedly
its targets? And why do morbidity and mortality among those with haemophilia
infected by contaminated blood products appear to be so much less than
among those who have acquired HIV by, say, homosexual sexual intercourse?
These questions were proper questions, if not the only ones that may
legitimately be asked about AIDS as a disease. Why, for example, is otherwise
rare Kaposi's sarcoma so commonly one of the consequences of infection
by HIV (and why is it uncommon among infected haemophiliacs)? Why is diarrhea
often one of the first symptoms of overt AIDS, and what can be done to
prevent its debilitating effects? Why is the "incubation period"
so long and variable? A full understanding of the pathogenesis of AIDS
would answer all these questions.
So why scorn Duesberg's demand of the research community for answers
to his proper questions? Part of the explanation is that Duesberg has not
been asking questions, or raising questions he believes should be answered,
but has been making demands and implying (but sometimes saying outright)
to colleagues, "Unless you can answer this, and right now, your belief
that HIV causes AIDS is wrong". It is as if a person were to have
told Schrödinger in 1926 "Unless you can calculate the spectrum
of lithium hydride, quantum mechanics is a pack of lies". (Interestingly,
that deceptively simple question is only now being answered.)
Unanswerable rhetorical questions are the stockintrade of
undergraduate debating societies. In the grownup world, the obligation
to answer even wellposed questions is a function of circumstances.
True, good theories (pace Popper) are falsifiable theories, and
a single falsification will bring a good theory crashing down. But unanswered
questions are not falsifications; rather, they should be the stimulants
of further research. Whether researchers divert effort from current preoccupations
to answer other people's questions properly depends on their personal judgment
of the cogency and relevance of the questions and even on the motives of
Duesberg has forfeited the right to expect answers by his rhetorical
technique. Questions left unanswered for more than about ten minutes he
takes as further proof that HIV is not the cause of AIDS. Evidence that
contradicts his alternative drug hypothesis is on the other hand brushed
aside. Thus Duesberg's reply to A. J. Pinching's question why, if transfusions
of Factor VIII are the true cause of AIDS among haemophiliacs, do patients
uninfected by HIV never contract AIDS, is tantamount to an assertion that
the patients must have been selected with bias or that the data must be
false (see Nature 350, 10; 1991).
For what it is worth, Duesberg's remark about the difficulty of recovering
virus from T cells is linked with the question of the incubation period;
both will probably be answered by studies provoked by the recent discovery
of large amounts of virus in the lymph nodes of infected people quite early
in the incubation period (see Nature 362, 355359; 1993). The
difference between the incidence of AIDS among haemophiliacs and homosexual
men is more apparent than real (see, for example, C. Lee et al. Br.
Med. J. 303, 1093; 1991) and is accounted for by the difference of
age distribution between the two groups. (The younger a person, the slower
the progression to AIDS.) The rhetorical question why infected haemophiliacs
rarely develop Kaposi's sarcoma is logically no more disconcerting than
the question why this rare condition is so common among homosexual men
Rhetorical techniques such as these are only barely forgivable
among otherwise friendly colleagues; people's patience with travesties
of science is understandably thin. Duesberg has made his debating technique
thoroughly intolerable by advertising his position to the AIDS community,
thus giving many infected people the belief that HIV infection is not in
itself the calamity it is likely to prove.
Nature's most recent refusal of an intended publication by Duesberg
was of his response to an article on the "drug hypothesis" by
M. Ascher et al. (362, 103; 1993), which used data on a group
of more than 1,000 men recruited in 1984 in San Francisco to show no correlation
between the incidence of AIDS and previous drugtaking. The likelihood
of developing AIDS was found to be 1.56 times as great among heavy drugusers
as among those using them more moderately or not at all, while the chance
of HIV infection was 1.43 times as great in the first group as in the second.
Duesberg's unpublished reply, on the basis of what is most charitably
called a misreading of the text, asserts that the authors must have fabricated
some of their data. He goes on to claim that the authors' argument supports
his view, not theirs. He quarrels with an imagined failure to collect data
on drug use after recruitment and claims that a twoyear study cannot
test the hypothesis of drug toxicity requiring ten years for its effects
to become overt. (Readers seeking further information will find the essence
of Duesberg's reply, provoked by a report by Ascher et al., in The
Lancet 341, 958; 1993).
Interestingly, as a referee of his unpublished letter to Nature has
pointed out, some of the most telling evidence against Duesberg's position
arises from the recent AngloFrench study of the use of AZT as a prophylactic
of AIDS in people infected by HIV (The Lancet 341, 889990;
1993). The negative finding of that study is also, incidentally, evidence
that AZT is not the dangerdrug that Duesberg has claimed. There is
no mention of that awkward circumstance in his intended reply to Ascher
The truth is that a person's "right of reply" may conflict
with a journal's obligations to its readers to provide them with authentic
information. Whatever Duesberg's friends say, the right of reply must be
modulated by its content.
Duesberg will not be alone in protesting that this is merely a recipe
for suppressing challenges to received wisdom. So it can be. But Nature
will not so use it. Instead, what Duesberg continues to say about the
causation of AIDS will be reported in the general interest. When he offers
a text for publication that can be authenticated, it will if possible be
published not least in the hope and expectation that his next offering
will be an admission of recent error. *