It's a starkly utilitarian idea: if you are already infected with HIV, receiving a transplant from another HIV-positive person doesn't threaten to make your life any worse; if anything, it could help prolong it. That's the premise behind the newly approved law that has passed through both legislative chambers of the American government and was yesterday signed and enacted by President Obama.

The HIV Organ Policy Equity (HOPE) Act lifts the ban on research into organ transplants between HIV-positive patients. It sets out guidelines and standards for how the research is to be conducted, and it'll be up to the US Secretary of Health to determine if its outcome gives reason to allow transplant operations to go ahead. Unlike most legislation, the HOPE Act is a mere three pages long and contains only three sections — it's an amendment to established law and its purpose is solely to open the door to responsible research into a potentially beneficial new procedure.