Rewire is publishing a series of articles and opinion pieces on global AIDS and HIV in conjunction with the International AIDS Conference in Vienna, which ended this weekend.  We welcome vigorous and informed policy debates on these and other issues. This post was originally published on the Bill & Melinda Gates Foundation blog.

I was honored to speak at the XVIII International AIDS Conference in Vienna. This conference marks an important turning point in the fight against AIDS.

There are good reasons to be hopeful – we have seen amazing progress. The number of people getting treatment for AIDS has increased twelve-fold since 2003. The people at this conference and major partners such as the Global Fund to Fight AIDS, Tuberculosis and Malaria and PEPFAR have helped make this possible.

At the same time, we have to recognize that these are tough times for those of us who are passionate about fighting HIV. Economic turbulence has driven up government deficits, and some countries have responded by reducing their investments in global health. These are the challenges we all face, but they don’t have to define our time.

Bill Gates meets with young men who have been circumcised or will be circumcised at the Bophelo Pele Male Circumcision Clinic in Orange Farm, South Africa.

And that is why, even as we are hopeful, we have to be honest with ourselves: We don’t have the money to treat our way out of this epidemic. Even as we continue to advocate for more funding, we need to make sure we’re getting the most benefit from each dollar of funding and every ounce of effort.

If we push for a new focus on efficiency, especially in prevention, we can, over the next two decades, drive down the number of new infections dramatically.

Here’s how we can do that:

• We need to scale up existing tools – like male circumcision and preventing mother-to-child transmission.
• We need to focus prevention efforts on the communities where transmission is the highest – such as men who have sex with men, injecting drug users, and sex workers.
• We also need innovations in basic science, diagnostics, computer modeling, and our understanding of the virus itself. This would make it possible to create new weapons for our fight against AIDS, prevent even more infections, and save even more lives. Vaccines, new diagnostics, and antiretroviral-based prevention (pills, injections and gels) are some of the new tools I’m really excited about.

If we scale up existing interventions and add new tools in the hardest-hit countries, it would change the face of AIDS. New cases would plunge. Millions more could be treated. The control of HIV would stand alongside the eradication of smallpox as one of the great public health victories in history.

This is the opportunity we have. We can keep doing things the old way, and keep getting the same result. Or we can push ourselves to make the most of every dollar of funding and every ounce of effort: to identify the most effective ways to save lives, and to share what we learn as widely as possible.

If we do that, we will have matched our compassion with the growing capacities of science, and we will start to write the story of the end of AIDS.

You can watch webcasts from the conference at www.kff.org/AIDS2010. Check the foundation’s HIV webpage for updates from Vienna throughout the week.