Is it permissible to invent a herbal cure for AIDS, knowing that the disease is mostly caused by fornication?

There is no objection to inventing a cure for AIDS if it does not encourage immorality, as penitents or those infected may benefit from it. It is a legitimate action because it provides benefit to others and alleviates their distress. It may also be used as a means to call those who commit immoral acts to repentance, on the condition that they are treated after their repentance.