There is an atmosphere of dejection regarding AIDS. Many people are asking themselves, ‘What should we do? Where do we go from here?’
The latest vaccine experiments do not give grounds for hope of encouraging results, nothing new of note seems to emerge. On the contrary, many experts in the field believe that a radical re-think on the type of approach to the vaccine for the HIV virus is necessary.
The statistics contained in the latest UNAIDS report are not very encouraging either. Yes, they speak of the beginning of a decline in the pandemic but in reality, looking at the graphs of the data, they seem to reflect a stationary situation.
This is the context in which we would like to assess what the project DREAM is today. It is a project with a special value that has always been capable of finding new paths and solutions. It is present in ten African countries, particularly in southern and eastern Africa: Malawi, Mozambique, Tanzania, Kenya, and also in Guinea-Bissau, the Republic of Guinea, Nigeria, Cameroon, the Democratic Republic of the Congo and Angola. It has a network of laboratories which number 18 so far, 31 centres which have treated 70,000 patients, several thousand babies who were treated at birth and are happily now HIV-negative and therefore assured of a more or less healthy life. We have followed more than 11,000 pregnancies and 8,000 healthy babies have been born. It is striking how steep the curve of the graph representing this data is.
So let’s reflect then on where we are going but also, in order to do so seriously, let’s look back at where we started from and remember the initial intuitions that were developing at the beginning of DREAM, before the programme ever got off the ground.
Those ideas now seem simple good sense. The idea that the HAART therapy could be a means for reducing both the mortality rate and the illnesses caused by the HIV infection. That the HAART therapy was a fundamental component in the prevention of the disease, an idea that was strongly contested at the time (more about this later). That the infrastructure needed in order to treat AIDS could also represent an opportunity to provide training, health education, prevention. That, last but not least, the treatment was not as exorbitant as believed, but instead could have a very high cost-benefit ratio.
Over time, many of those intuitions have received positive confirmation. It was satisfying to read that in 2007 UNAIDS officially recognised that the decrease in the AIDS mortality rate in Africa could be an effect of the life–prolonging HAART therapy. We had the pleasure of being invited to a WHO meeting in Geneva last November to discuss the use of the tri-therapy during pregnancy and breast-feeding where we read and listened to many other studies that corroborated the results of the DREAM project. Last November’s meeting was an important one to be present at as it prepared the groundwork for the WHO’s new guidelines which will be published in the coming year. Most probably the approach advocated by DREAM, that is, the administering of the tri-therapy during pregnancy and for the first six months after giving birth, will form the basis of the recommendations that the WHO will make for the benefit of those responsible for deciding on health policies in different parts of the world. This is all very pleasing. It means that DREAM has not only treated people, it has also contributed in finding global solutions while maintaining a high quality profile.
A study about to be published in Paediatric Infectious Diseases shows that among our newborn babies in Mozambique the rate of HIV transmission is lower than 3%, while the rate of survival free of illness (that is the percentage of babies who both survive their first year and are HIV- negative) remains above 92%. This is an extremely positive statistic. The infant mortality rate in Mozambique is 10%, so the fact that we have a 92% survival rate of babies from mothers who are all HIV-positive represents a great success.
In Malawi too we are seeing exceptional results with a very low transmission rate of the virus from mother to child. Our convinced change from artificial feeding to breastfeeding in 2006 has not only further reduced the virus transmission rate but has also reduced both the mortality rate in general and the numbers of those who abandoned the programme during the follow-up phase. And what is interesting is that these are not abstract figures coming from the laboratory. No. It’s what is happening in the field, in African public health centres run by local people.
The transmission of the HIV virus can be stopped. We have said it and seen it. But we would like to do more. We would like to win the battle against AIDS. So then, the question is, can AIDS be defeated?
We believe that the challenge now lies in extending the treatment to provide a more complete coverage at a regional and national level. We have estimated the benefits that would derive from applying the DREAM approach for the prevention of mother-child transmission to the whole of Africa. If we reckon that more or less 30-40% of newborn babies born of HIV-positive mothers become infected during their first year of life, and if we assume (as happens in reality) that 80% of women accept our protocol and follow it correctly for at least six months after giving birth, we could in any case prevent three out of four babies from becoming infected. In Africa in 2007, there were 1,125,000 HIV-positive pregnant women. If we had applied the DREAM protocol we would have saved the lives of 300,000 of the approximately 400,000 babies who contracted the infection either during pregnancy, birth or breastfeeding. Clearly, the challenge is enormous and touches the lives of many newborn babies.
In addition, a different modality for stopping the tri-therapy after six months of breastfeeding has been identified and adopted. It is based on a ‘tail-end’ principle. First, Nevirapina, the drug which remains in the organism for longer is stopped, followed only after three weeks by the other two types of drugs. Thanks to the installation of equipment for testing mutation in viral resistance at the Blantyre laboratory in Malawi, it was possible to carry out tests in 2007 on a first group of patients. The initial results seem very encouraging: among 26 women who had stopped the tri-therapy following the ‘tail-end’ procedure, no resistance to any of the three drugs used during treatment was observed. We expect to be able to reply soon to those who object that the tri-therapy is dangerous as a preventive procedure. On the contrary, today we begin to see that it is highly effective and that, if anything, as documented in scientific papers, it is the mono or bi-therapies which create big problems in drug resistance.
What then is the real effect on the mothers of the DREAM approach? Even three years after stopping the HAART, pregnant women have a CD4 level and viral charge comparable to initial levels (in other words, good: women who are pregnant are by necessity women in reasonable health). Women who have suspended the HAART for three years are well. Their viral charge does not present particular problems so the HAART benefits the mother as well as the newborn child..
Furthermore, the therapy has another positive element because it prevents the sexual transmission of the infection, the main modality of transmission in Africa. Interesting results concerning this point come from studies of HIV- discordant couples where one partner is HIV -positive and the other is HIV- negative: in the pre-HAART era (1991-1996) in Europe, not Africa, 10% of the HIV- negative partners became infected. Since the HAART became available to the HIV-positive partners, the transmission rate has been practically reduced to zero.
It leads us to think then that the mother-child transmission prevention therapy does not only protect the baby from infection, and is not only of benefit to the mother but that it also has a positive effective in HIV-discordant couples, official or not, in lowering the number of cases of infection. It has been objected that the HAART can offer such a sense of security that people no longer take precautions against becoming infected. But this objection has been disproved in two different studies based on tests carried out in Taiwan and in Canada: results show that in any case there is an approximately 50% reduction rate of new cases of infection, measured year after year.
The rate of the spread of syphilis, a sexually-transmitted disease, used as a marker of behaviour, has remained stable in Taiwan and has increased in Canada but, in both cases, the introduction of the tri-therapy has led to a marked reduction in the number of new cases of HIV infection. The results of these studies seem to provide a clear answer to the previous objection concerning the possible sense of security that access to the antiretroviral drugs may induce. It has been proved that in any case the treatment is effective in preventing new cases of infection, above all if it is extended to the large majority of the population. Can this concept be generalised? Yes, at least in places like Europe and the United States where 95% of those who are HIV-positive are covered. The real effectiveness of the prevention therapy depends upon how widespread it is. Where this is the case, year after year the number of new cases of infection represent only 3% of the old cases. Where, on the contrary, the therapy is not widespread, the increase rate is equal to 11% and can reach 14% as is the case in Eastern Europe. So treating everyone means having fewer cases of infection to deal with in the years to come.
In the larger part of the world, only 10% of those who are HIV–positive have access to treatment and this is the problem we have to face in the coming years. We realise that we are talking about millions and millions of infected people but at the same time we sense that our initial intuition for DREAM, that of therapy as a fundamental component of prevention, is today the centre of attention in studies worldwide. It does indeed contain the possibility of hope for a solution to the pandemic in the future.
The solution for defeating AIDS may not come from the discovery of a vaccine, it may instead come from a widespread programme of treatment extended to all those who are infected or sick. It seems to us that never as in this case have fairness and effectiveness been so inextricably linked and are the inspiration for the united array of initiatives needed to eradicate this illness.