Editor 's note : Dr. Anthony S. Fauci , world-renowned HIV/AIDS researcher who has been on the forefront of battling the disease since it was discovered , previews his speech to this week 's International AIDS Conference . Dr. Anthony Fauci is cautiously optimistic that eventually some AIDS/HIV patients will be cured . WASHINGTON -LRB- CNN -RRB- -- This week , more than 25,000 people from the global HIV/AIDS community are in Mexico City , Mexico , attending the XVII International AIDS Conference . I am pleased to be among them . This is the first International AIDS Conference to be held in Latin America , a region hard-hit by the HIV/AIDS pandemic , but also a place where exceptional scientific and public health advances have been made . The theme of the conference is Universal Action Now , which stresses the need for scientists , policymakers , activists and other concerned citizens everywhere -- in rich countries and poor ones -- to work even harder to defeat a scourge that already has claimed more than 25 million lives . We have made considerable progress against HIV/AIDS , not only on the scientific front , but also with regard to the political will , funding and essential public health efforts on the ground that are delivering medicine , care and prevention services . However , much remains to be done , as 2.7 million people worldwide were infected with HIV in 2007 . Watch more on the International AIDS Conference '' In the United States , the rate of new infections continues at an unacceptably high level , especially in the African-American community . In my home city of Washington D.C. , a staggering 5 percent of the population is infected with HIV , a rate that rivals those in sub-Saharan Africa . Eighty percent of my infected neighbors in Washington , D.C. , are African-American . Throughout the United States , we are seeing a resurgence in HIV cases among men who have sex with men of all races , with African-Americans again hardest hit . Despite what you might hear , the AIDS pandemic is still raging . Many hundreds of presentations at the conference are dealing with important research on the basic biology of HIV and its disease-causing mechanisms ; the complex immune responses to the virus ; and advances in tools to diagnose , treat and prevent HIV . My talk on Wednesday , is called `` Looking to the Future : New Directions in HIV/AIDS Research '' and will look at all these issues , and the many challenges -LRB- and opportunities -RRB- in AIDS science . But I hope to leave the audience with at least a tentative answer to an important question I get all the time : Will we ever have a cure or a vaccine for HIV ? Despite our considerable success in managing HIV infection and improving the length and quality of life for people living with HIV , there is no well-documented case of anyone being truly cured of HIV disease . This is because HIV is unlike virtually any other virus in its ability to hide from the immune system in protected cellular sanctuaries that we call `` latent reservoirs . '' We know that these reservoirs are established within days of infection , and even our most potent combinations of anti-HIV drugs are unable to purge the virus from these hiding places , even in people who have been on therapy for a decade or more . If you take a patient off his or her anti-HIV therapy , the virus hiding in these reservoirs springs back , and soon billions of viruses are renewing their assault on immune system cells and other organs . Photos chronicle AIDS treatment worldwide Our best hope for eradicating HIV from the reservoirs may be to diagnose and treat people aggressively very early in infection , before the reservoirs have become too large . Our laboratory and other groups are testing this approach with intensive regimens of new drugs that prevent the virus from entering cells or from inserting its genes into a cell 's DNA . Even if the virus is not completely eradicated , such early , intense treatment , perhaps with the help of immune-boosting drugs , might keep the reservoir small -- and the immune system strong -- thereby allowing a person to come off therapy . This would be a `` functional '' cure . Other approaches are being pursued as well . A cure is critical to our attempts to ultimately contain the pandemic . Currently , for every person put on therapy , two to three people are newly infected . As antiretroviral therapy is at present a lifelong commitment , it is extremely unlikely that we will have the logistical or financial capacity to reach and treat -- indefinitely -- everyone who requires antiretroviral therapy . As we search for a cure , we should of course continue our efforts to provide proven , lifesaving antiretroviral drugs to every person who needs them , regardless of where they live . Many promising avenues of prevention are being discussed in Mexico City , but none is more essential than an HIV vaccine . HIV vaccine development has been frustrating and challenging for a number of reasons , including the fact that the virus mutates rapidly , hides from the immune system , and targets and destroys the immune system cells that are successful in fighting and clearing most other viruses from the body . With HIV we will have to do better than nature if we are to develop a vaccine ; HIV is unlike the situation with other viral diseases such as measles and influenza , where we have been able to mimic natural infection and induce protective responses with vaccines . My institute and many other organizations around the world are working on this problem , and advances are being made . For example , we have made progress in identifying the structures on the virus to which infection-fighting proteins that can neutralize HIV -- so-called neutralizing antibodies -- bind . Now , our challenge is to turn these structures into vaccines , and conduct the clinical trials that prove they work in people . My complete talk will be available as a webcast at the conference Web site , but let me give you the quick bottom line : I am cautiously optimistic that we will be able to cure some patients under certain circumstances , and I am also cautiously optimistic that we will develop a vaccine that will protect some people against HIV infection , or slow the progression of disease in some patients who do get infected . Meanwhile , we need Universal Action Now to accelerate the exceptional momentum of the past few years -- particularly during the past year -- in delivering proven tools of HIV prevention and therapy to communities around the globe . Anthony S. Fauci , M.D. , is director of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health .