Fight against HIV

On Thursday, American scientists announced that they had discovered new antibodies they say can neutralize approximately 90 percent of known strains of HIV. This represents a significant step forward in HIV and AIDS research. The antibodies - the most powerful known to scientists so far - were discovered in the cells of an African-American gay man, who is known to scientists only as Donor 45. Deutsche Welle spoke with Georg Behrens, an immunologist and HIV physician at the University of Hannover, about what this new research could yield for future treatments and a possible HIV vaccine for patients around the world.

Deutsche Welle: What does this discovery mean and why is this significant for HIV research?

Georg Behrens: I think this is very important because we know that antibodies are potentially very effective molecules to fight HIV. The problem is that everyone who gets infected with HIV produces these antibodies but they do not really work because the virus has different strategies in order to make them not useful.

And over the last years there have been different trials in order to study whether we can induce immune response and antibody responses in uninfected and also infected patients in order to produce antibodies which are more effective against HIV. There has been some progress but there has been some skepticism as to whether this is going to work because there is strong evidence that the virus can mutate and can use new strategies to avoid these antibodies from binding.

What these researchers have now discovered and managed to figure out is what the best location on the virus is to have an antibody directed against so that this antibody then prevents the virus from infecting cells. They apparently spotted an area which is extremely effective and this area cannot be mutated by the virus because it needs this area; it cannot change this area in the surface in the virus and that's why it's so important to have this information. This will now facilitate how to make or how to induce antibodies in other patients.

As I understand it, an antibody is just a particular kind of protein.

It's a sort of protein that is produced by the immune system in response to many infections. So that's what we need against influenza or against other viral infections. A big question in HIV is whether antibodies alone will do their job. Most likely they won't. But they are very important, they are particularly important - many researchers believe, at least - in preventing getting the disease at all.

How important they are during the course of the disease, there is more debate on this. The hope is, with this new knowledge, to be able to generate a better vaccine that will protect people from becoming infected.

So potentially this research could be used to help create an HIV/AIDS vaccine?

Exactly. That's the big hope. Because that was one of the major challenges: How can we generate one, two or many antibodies in a person so that these antibodies will persist and will protect this individual for a long time even if he is exposed to the HIV virus.

Now I understand that this antibody that they discovered was in the body of a patient. Does that mean that this antibody could potentially be produced by anyone?

That's an excellent question. Indeed it was hard work to screen many, many patients in order to find these specific antibodies and what's also unique in this situation is that novel techniques from molecular biological methods were used in order to fish the antibodies out of the serum of infected people. So it was found in a patient and now the question is: Are more circumstances required to induce this antibody or is everyone principally able to produce this sort of antibody? That's the major question.

So far, this antibody could be produced from the cells of this patient, so you can make larger amounts of this antibody in the future and you can use it to study it more in patients or in animals, or whatever. But the question is: is it possible in any given individual to induce this sort of antibodies? And that will take quite awhile before we know.

This research seems very promising. What would be the next step if these scientists have been able to say that this antibody can fight against 90 percent of known strains of HIV - presumably there would have to be confirmation of these results, yes?

Yes, I think there are several questions. One important point is - and they have already shown some results with regard to this - that this really acts, this antibody, against different strains of HIV. The virus has different variations and looks different in different parts of the world. But this looks very promising. The part is done so far in vitro cultures, mostly. So the next major question is: How efficient is this antibody in a real life situation.

In an actual organism?

Exactly. In an organism like in an animal or in a patient. Would the production of the antibody and then the transfusion into a patient have an impact on the viral distribution or the replication or something else. That's hard to say so far. We would have to see that. The other question would be: How much of this antibody would be required, if you transfer it into an individual or an animal, in order to prevent an infection if that individual is exposed? And then coming back to what you asked already, is it possible to induce this antibody so that every individual is able to produce and generate this antibody with his own immune system. And that's one of the major questions.

Could it be possible for this antibody to be used for a treatment or a cure or does it go more in the vaccine direction?

I think it could be used for a treatment - not necessarily to broaden the spectrum of different treatments, but just to show that it's active, it's working and it's protecting cells from becoming infected.

In other words you could slow down or maybe even stop the production of the virus.

Exactly. That would be something that would really again show that these antibodies are working and that there are other questions: For instance, how long does it circulate in patients after transfusion. I think that it's not very helpful in terms of eradication, in 'curing' the disease. The major obstacle in eradicating HIV is the virus that is already within the cells and that is probably even within the genome of the host. And these antibodies do not act within the cells, they protect the cells from becoming infected.

In the long term I think it's most important for vaccine design and coming closer to a very effective vaccine against HIV.

We hear a lot about how AIDS and HIV infection are very prevalent in the developing world and especially in sub-Saharan Africa. Can you give us a sense of how this might compare with other types of figures in Europe, or other parts of the world? Obviously places that have higher rates of infection are going to be more interested in this type of treatment.

Well, as you said, developing countries and in parts of Eastern Europe have a much higher prevalence of HIV-infected patients, so they have far more interest.

In Germany about 60,000 to 70,000 people are affected with HIV. Most of them have perfect access to the modern treatments and these medications are very effective in controlling the disease at least for a very, very long time. We achieved also about 40 percent treatment coverage in other countries in Africa for instance, and other non-developed countries, but there is still a lot of things to be done in order to really provide the required health care and the medication for everyone who is in need.

So, the ultimate goal will be that we find a vaccine, because I don't see another way to prevent other people from becoming infected. There is no way around even with the modern treatments I don't see a realistic points in the next 10 or 20 years really to halt this epidemic. A vaccine is the only thing that we really can hope for.

Interview: Cyrus Farivar

Editor: Kate Bowen