The US has lifted a 22-year immigration ban which has stopped anyone with HIV/Aids from entering the country.

美国提出一项长达22年的移民法，禁止任何艾滋病病毒携带着入境。

President Obama wants the US to be a world leader on HIV research

President Obama said the ban was not compatible with相配的 US plans to be a leader in the fight against the disease.

The new rules come into force on Monday and the US plans to host a bi-annual一年两次的 global HIV/Aids summit for the first time in 2012.

The ban was imposed at the height of a global panic about the disease at the end of the 1980s.

It put the US in a group of just 12 countries, also including Libya and Saudi Arabia, that excluded驱逐，排除 anyone suffering from HIV/Aids.

The BBC's Charles Scanlon, in Miami, says that improving treatments and evolving public perceptions认知，理解 have helped to bring about the change.

Rachel Tiven, head of the campaign group Immigration Equality, told the BBC that the step was long overdue迟到的，过期的.

"The 2012 World Aids Conference, due to be held in the United States, was in jeopardy危险 as a result of the restrictions限制条件. It's now likely to go ahead as planned," she said.

In October, President Obama said the entry ban had been "rooted in fear rather than fact".

He said: "We lead the world when it comes to helping³ stem the Aids pandemic流行的，普遍的 - yet we are one of only a dozen countries that still bar people with HIV from entering our own country."