The man that got it right

Published 14, Nov, 2017
Author // Bob Leahy - Publisher publisher Bob Leahy in conversation with Dr. Pietro Vernazza, famous author of the once-scorned Swiss Statement which predated U=U by ten years.

The man that got it right

Dr. Pietro Vernazza being interviewed  in the studio with Bruce Richman in Paris at !AS2017

About the Swiss Statement: Source aidsmap

There is evidence of some groups of gay men knowing, from the late 1990s onwards, that people with an undetectable HIV viral load were much less infectious, and were using this knowledge in sexual decision-making. Public discussion of this became much more high profile after a paper was issued by the Swiss Federal Commission for HIV/AIDS in January 2008.

The statement caused widespread concern amongst some prevention and public health advocates who felt it was based on weak evidence in some areas and risked undermining people’s efforts to maintain and promote condom-based safer sex.

The statement said that people with HIV are not sexually infectious (“ne transmettent pas le VIH par voie sexuelle”), as long as the following conditions are met:

.The HIV-positive individual takes antiretroviral therapy consistently and as prescribed and is regularly followed by his/her doctor.

. Viral load is 'undetectable' and has been so for at least six months.

. The HIV-positive individual does not have any STIs.”

Bob Leahy: Pietro, thank you for talking to I’m going to begin by asking you a question which I have heard posed to you before, I think in Paris, and I know your response. But it’s an important commentary on our history and Swiss Statement history. That question, of course, is “do you feel vindicated?”

Dr. Pietro Vernazza: Yes and no. In 2008, there were some people saying we got this wrong. For that part of the criticism I feel vindicated. However, the big criticism at the time was “you don’t have the data to say this” and the critics would still say this today “you didn’t have the data at the time, so it wasn’t correct to do the statement”. This criticism does not take into account the experience we had at the time, and more importantly, they still don’t consider our key argument: we had absolutely no evidence of the opposite, the risk of passing the virus under these circumstances.

I think I heard you say “yes” in Paris. (laughs). But you raise the question … since your statement we have had HPTN052, PARTNER and Opposites Attract. But it was still really the community and the U=U campaign, I think, that really got the word out and weighed in with the “news” that people who are undetectable can’t transmit the virus sexually?

I would agree for the United States, Canada and many other countries. I cannot agree with regard to Switzerland, because it was in Switzerland that health care professionals came together with this statement, and this is what we were telling our patients; no question that we all gave the same information. So that’s completely different.

So what is your reaction to the U=U campaign in at least bringing the message to large parts of the world?

I congratulate all these people who are working on the campaign and made it possible. I have a hard time accepting that such an effort was necessary. There was a community that at the time was against publication of this message; they were suppressing it, always with different arguments. We had a hard time. That is one part. But that the same people insisted their stubborn position even five years after the HPTN052 Data was presented in Rome is just incomprehensible to me.

Yes, I want to ask you about that Pietro, because in 2008 when the Swiss Statement came out and again in Mexico City - I was there when you had a special session at the International AIDS Conference – some people thought it was a dangerous message to put out, that there might be risk compensation, that it threatened condom campaigns. What did you think when you heard that kind of reaction, that we shouldn’t be saying this because of the consequences?

We already had data to support that none of that is the case. We had data from California that observed an obvious increase in condomless sex and an increase in STI’s in a population that was very well treated but without an increase in HIV incidence. The impact was in fact much bigger because as a result of the Statement, many more patients were motivated to get treatment. Those patients that weren’t motivated in the past and whose CD4 counts were OK had a new argument to get treatment. Not to be infectious means a lot to an HIV-positive patient. That effect which was much bigger than we anticipated was clearly helping to reduce the incidence of HIV. So these theoretical fears that people, had – the arguments were just very weak.

The suggestion then that we should NOT release factual information about HIV risk because of the potential or perceived consequences raises ethical questions, does it not?

The whole statement had a strong ethical basis. If we know that we don’t see any cases of transmission, patients have a right to know; it’s not ethically correct to tell the patient you could still transmit (if they are durably virally suppressed.) There is a strong ethical principle; when you have strong evidence of risk to a patient in your care, you have an obligation to tell the patient of that risk. That’s correct medical management. Now, if you have no evidence of risk, the same is true; it’s not the obligation of the physician to select which information to present to the patient. It becomes a little bit more clear with a related issue we are following at the moment: breast-feeding by HIV-positive. mothers under therapy. We are preparing a publication now which says the risk of breastfeeding (when the mother is undetectable) is minimal or negligible. We have never seen a case of transmission. We have to tell this to HIV-positive mothers under treatment, because the risk of not breast-feeding is also relevant. You have to tell the patient that there might be a risk of transmission, but we have not seen a true documented case. We also have to balance this with information about the advantages of breast-feeding, which are numerous. In such a situation we shouldn’t tell the mother “don’t breast-feed”. We are obliged to tell them that breast-feeding is an option and have to support a shared decision making process.

It’s interesting, Pietro that we are talking a lot about ethics now, and ethics don’t always come in to discussions about HIV. I actually welcome this kind of discussion. And on this topic (U=U campaign leader) Bruce Richman has suggested we have been selective in the past whom we tell U=U-related science to in that the medical profession makes judgements on who is equipped to hear it, based on the patient’s behavior, their socio-economic status, etc. What do you think about that?

Bruce, of course, is correct. It is not on us to decide who may hear a true fact. Medical knowledge that is needed to influence your health behavior must be made available to everybody.

I want to ask you something else. I was at the Paris Press Conference on the topic of U=U. You came to the microphone and said something that really impressed me. I’ll paraphrase . .”the onus now is on people to prove that people with HIV who are durably undetectable CAN transmit the virus sexually.” Tell me why you said that.

I would love to. That was a position I suggested in 2008. It was never accepted by many opposing colleagues. In order to disprove a hypothesis (that HIV can’t be transmitted), I have to have a case that shows HIV WAS transmitted. That is the way how science works. It’s a fundamental concept and it’s based on mathematical fundamentals. We have discussed this so many times and I have never received a good response from the opposite side. Let’s put it vice-versa: I make the statement that HIV is not transmitted. They say “you have to prove it’s not transmittable”. However, to disprove a hypothesis you must disprove the opposite. Mathematically you can only prove that something DOES occur; you can never prove it WON’T occur. You can observe 10 cases, 20,000, or one million cases … the one million and first could still transmit. It is impossible to prove a negative. You can only prove the positive. That’s why I said in the very beginning: the scientific way of looking at this is to prove the positive (that transmission can occur.) Now every physician until 2008 told their patient (who was on HIV treatment) they were infectious. But I would ask “what is the evidence to support this statement of infectiousness for that situation?” That was my point; there was zero evidence and ten years after publication of the Swiss Statement there is still no published, documented case.

Dr. Pietro Vernazza at the U=U press conference in Paris at IAS 2017

I would add Pietro as a community member we hear variations on undocumented cases somewhat frequently. People say things like “a friend of mine was infected with HIV by someone with an undetectable viral load.” As a result of that they don’t believe U=U. What would be your response to that?

It’s difficult. But it is a repeating pattern we see with many other examples of misinformation. The common pattern is always With regard to this specific topic I would still say that every doctor in an HIV practice who observes such a case and proves it would publish it. Such as paper is a citation booster and can readily be published in any prestigious medical journal.

Right. Let me ask you another question. Some in the community of people living with HIV latched on to the power of antiretrovirals as a prevention tool way before U=U, way before AIDS Service Organizations acknowledged it. Why?

I think in this situation of rejection of the Swiss Statement by professional organizations, this was the only alternative for a person with HIV to free themselves. When we issued this statement I was very well aware of the responsibility I had. I knew if my statement was wrong I was putting people at risk. I wouldn’t have done it without researching and arguing about it for a long time.

So you had done your homework and you were convinced it was the right thing to do. Talk more about your reaction when so many organizations, including here in Canada, essentially rejected the message and said “don’t pay any attention to the Swiss Statement, it’s business as usual.” Disappointment? Anger?

Not really, I anticipated some backlash. But in Switzerland we had prepared this very well and involved a large group of professionals working in the field. But when such a strong reaction comes from outside, for a group this strengthens the position. We stuck together. In 2008 I was invited to give presentations around the world and after every presentation I left with my head up, I felt I defeated every argument. Really, there was never an argument against the statement that held true after rigorous discussions.

So you felt you won then and you must feel you doubly won ten years later. I have to say, Pietro, you are one of the heroes of our movement. You deserve the Nobel Prize. It’s been great to reconnect with you. Do you have a final message you want to share?

My job was only to stick to the expertise we had and to talk openly about it. I want to say - perhaps I haven’t stressed it enough – the U=U campaign to me is like something I have been expecting for a long time. I was expecting the CDC and physicians, etc. to openly speak about the consequences of our evidence such as HPTN 052. But no, it took the community to finally communicate the truth. I have to congratulate everyone who helped in this movement. I have been approached over the years by many individuals who have a fear of transmitting HIV, it is time, to end the fears! I have talked to many individuals in jail sentenced for not having caused any risk to anybody; still in these days. It is about time that this terror comes to an end. I really think these community members who were active on U=U did a great job.

That seems like a great place to end. Thank you, Pietro, for that and thank you so much for talking to

About the Author

Bob Leahy - Publisher

Bob Leahy - Publisher

Award-winning blogger Bob Leahy first made his social media mark a decade ago on where there are still to this day almost 3,000 entries of his available to be read. He was a featured blogger on Ontario’s campaign, along with founder Brian Finch. He joined at its inception in 2009 and became it's Editor a year later.

Born in the UK, Bob’s background is in corporate banking, which he gladly left in 1994, after being diagnosed with HIV the previous year.  He has chaired the board of PARN (Peterborough AIDS Resource Network) and has been an executive board member of both the Ontario HIV Treatment Network (OHTN) and the Canadian AIDS Society (CAS).  He was inducted in to the Ontario AIDS Network’s Honour Roll in 2005.  Bob is currently a member of Ontario’s GMSH (Gay Men’s Sexual Health Alliance). He also writes for

In 2012, Bob was honoured with the Queen Elizabeth II Diamond Jubilee medal for his work and commitment to HIV/AIDS in Canada.

Bob continues to write for this site while in the Positivelite.Com editor’s seat, with a particular interest  in HIV prevention, theatre and the arts in general. He is accredited media for a number of Toronto theatres. He lives in Warkworth, Ontario with his partner of thirty-two years and three dogs.