An HIV cure is feasible?

Today, in Nature Reviews Immunology, The International AIDS Society (IAS) Scientific Working Group on HIV Cure published an opinion piece that summarizes their recommended key goals for the international community to establish a cure for HIV (http://www.nature.com/nri/journal/v12/n8/full/nri3262.html).

Combination, compliant use of antiretroviral drugs can improve the health and prolong life in HIV-infected individuals, and can reduce the rates of transmission. However, antiretroviral drugs do not fully restore health or normal immune status in patients – or eliminate the virus from their cells. In addition, only a minority of HIV+ people worldwide have access to antiretroviral therapy. Although the price of antiretroviral therapy has dropped, the cost of providing drugs to all 33+ million people infected with HIV for the rest of their lives is astronomical. But without treatment, the virus will be spread by those that remain untreated.

The IAS identified seven key priorities that will allow us to achieve a sterilizing (elimination of all HIV infected cells) or functional (lifelong control by immune system in absence of therapy, virus not completely eradicated) cure.

The key priorities are:

-       “determine the cellular and viral mechanisms that maintain HIV persistence during prolonged antiretroviral therapy and in rare natural controllers” – focus on establishment of latency, ongoing viral replication, homeostatic proliferations

-       “determine the tissue and cellular sources of persistent simian immunodeficiency virus or HIV in animal models and in individuals on long-term antiretroviral therapy”

-       “determine origins of immune activation and inflammation in the presence of antiretroviral therapy and their consequences for HIV or SIV persistence”

-       “determine host mechanisms that control HIV replication in the absence of therapy”

-       “study, compare and validate assays to measure persistent HIV infection and to detect latently infected cells”

-       “develop and test therapeutic agents or immunological strategies to safely eliminate latent infection in animal models and in individuals on antiretroviral therapy” – reverse latency, clear latently infected cells

-       “develop and test strategies to enhance the capacity of the host immune response to control active viral replication”

While these points are important, likely necessary to develop a cure, I wonder if we are anywhere close to answering these questions. Although a cure is sure to have the greatest impact on eradicating HIV, other issues also need to be addressed. Despite effective prevention options (condoms), 2.7 million people are infected with HIV each year. Alternative prevention strategies (Truvada, microbicides, vaccine) could lower transmission rates.  If you stop (or significantly lower) the spread, new infections can be prevented, which lowers the number of people that need treatment (or the cure, when developed). Preventing the spread of the virus should also be a focus, because there is no guarantee that everyone infected with HIV will receive the cure. This brings me to my second point, which is that many people (both those at “high risk” and those at “low risk”) do not know their HIV status. If a cure is developed, how do you ensure that everyone that is HIV+ receives it? Unless mandatory and regular testing of every single person is undertaken people that don’t want to get tested, or people who think they are “low risk” and have no need for testing, may continue to spread the virus. If the goal is an “AIDS free generation”, more than the science needs to be taken into consideration.