Two European studies on pre-exposure prophylaxis (PrEP) of the finished randomized trials after its interim analyzes have demonstrated that in both cases the effectiveness of PrEP was so high that it would be unethical not available to all participants. AssaysPROUD e IPERGAY will continue, but with all participants taking Truvada (tenofovir / emtricitabine) as a preventive measure against HIV infection.
It is expected that full data will be presented at the Conference on Retroviruses and Opportunistic Infections (CROI) in February, but it is also expected that the trials will show the highest levels of efficacy ever seen in studies on PrEP. The UK PROUD study provided 545 gay men in a situation of greater vulnerability to HIV infection a safer sex support package and half of these participants were immediately given a daily dose of Truvada® as PrEP, while for the other half the PrEP provision was deferred for one year. The main objective of the study was to see if the risk behaviors for the participants' infection changed if they knew they were taking PrEP, but when an interim analysis by the Ethics and Data Monitoring Committee (IDMB) showed a significantly lower number of infections for HIV in people under PrEP, a decision was made to close the randomized trial phase on 16 in October. However, in France and Canada, the IPERGAY trial has tested a new intermittent PrEP regimen with 400 gay men. Participants were asked to take a double dose of PrEP the day before they had sex and also within two days after the sexual act. They were randomized to either Truvada® or placebo. Raised in part by the announcement of PROUD, the IDMB of IPERGAY also conducted an interim analysis and concluded that the effectiveness of the trial regimen was so high that it would not be ethical to keep participants on the placebo. Therefore, it was announced on 29 in October that Truvada® would be made available to all participants. Comment: It is important to anticipate the final values of the effectiveness of these studies, which will probably be presented at CROI in February, but it is already clear that this is a significant development in research on PrEP. The previous tests, although having a high effectiveness among people that really took also reported poor adherence, which impacts the effectiveness of the scheme. These seem to be the two first tests to demonstrate high efficacy at a general level, at least among gay men by that membership should also be high among most participants. This comes to suggest, more strongly than previous studies, that PrEP could be a practical and effective means of prevention among those most vulnerable to HIV infection and who are motivated to take. This news gave rise to Community declaration by organizations working in the field of prevention in the UK, open to subscriptions, which require faster access to PrEP. Seehttp://www.prepaccess.org.uk to subscribe.
Progress in vaccines for HIV: New tests on humans in 2016?
A study in which it was given to South African volunteers RV144, the only regime in vaccine so far has shown some effectiveness in preventing HIV infection, found stronger immune responses among volunteers in this country than in the original study, in Thailand. A new study, the HVTN100, which will begin in January, will administer to more South Africans a version of RV144 tailored specifically to the most common HIV subtypes in South Africa. If this produces stronger immune responses, a is planned for 2016. Investigation of the immune responses of participants in the Thai study who received a potent dose of RV144 eight years after the original study demonstrated that the responses generated could only "neutralize" (ie, prevent cell infection) HIV strains who had not developed resistance to attack the human immune system. However, there were promising signs that the enhancers were "pushing" the immune system of some of the participants towards the development of what is often called neutralizing antibodies, which succeeded in disabling most HIV strains. Another study in humans, which could start in 2016, will have smaller, will administer a vaccine involving HIV antigens (proteins signal) around another virus, CMV (cytomegalovirus). This vaccine does not prevent infection but does HIV infections, rendering them harmless, by ending these, in most cases, disappeared in the body. Sixty percent of a group of monkeys who were given the virus and then infected with the simian version of HIV (SIV) esttá now, three years later, free of infection and the experiences of this year will see if the vaccine, when administered to apes already infected with SIV, will result as a medicinal product, allowing them to stay healthy without antiretroviral therapy (ART). If this happens, the human clinical trials will begin in 2016. Comment: The slow pace of vaccine development for HIV sometimes leads to doubt that this process ever ends. The slow process due to the fact that the HIV virus while preventing the normal immune response to viruses such as reproduction, is more bitter than other enemy subtle but relatively less developed viruses, such as Ebola. The development of a vaccine for HIV involves mainly new scientific knowledge and its complexity is comparable to a large space project. In any case, recent research continues to progress, either to improve existing approaches, such as RV144 either by random findings as CMV vaccine.