Cure is the name of the Hepatitis V antidote found on the HBO original series True Blood. An antidote originally ingested by Sarah Newlin, mistress of the now deceased Governor Truman Burrell, and ex-wife of Fellowship of the Sun televangelist Steve Newlin, Sarah's blood has become infused with the antidote, giving it healing properties, and thus curing Hepatitis V.
When the virus was made, the scientist just didn't make the virus, but created an antidote to go along with it, known as the "Cure".
The cure was made sometime during 2008-2013. It may have just been 2013, but scientists must have made it beforehand via Sherman, founders of the Vampire Lab. It now resides within Sarah Newlin's body when she swallowed it during the escaping of the vampires. The cure doesn't have to be synthesized, but can just be drank from Sarah, as shown by Eric Northman when he attacked Sarah and the virus (veins) started to disappear, showing that he was cured.