The long fight against HIV AIDS may get a powerful new weapon.

A new drug taken by injection only twice a year shows great promise in preventing new HIV infections.

It could have far-reaching impacts, especially in lower-income

countries that are facing rising infection rates.

William Brangam has the details.

That's right. This drug is called Lena Lena Capavir and it is made by the

drugmaker Gilead which recently said that in a clinical trial of 2,000 patients

in South Africa and Uganda not one person taking the drug was infected with HIV.

So if this drug pans out as hoped, what would that mean for global HIV care?

To understand that, we turn to one of the world's leading experts in HIV treatment and prevention.

Salim Abdul Karim is the head of Caprisa, one of South Africa's top HIV AIDS research centers and which helped run this study.

Salim Abdul Karim, so nice to have you back on the program.

As I mentioned, this drug is not yet approved for use in the marketplace, but let's say these results hold up. What would this mean? How potent a tool would this be in the fight against HIV?

Great to be here with you, William.

Well, in my 40 years of doing AIDS research,

I have never seen the result like this absolutely amazing to see a drug like this that provides a hundred percent protection.

So when you look at a drug like this and given that it's in a completely new class of

anti retrovirus we do not have circulating resistance to this drug and so we are seeing high levels of

protection because it's not a drug that the virus has already been exposed to. But its potential as a highly

efficacious prevention mechanism is enormous. Given that our goal is to try and end the AIDS pandemic by 2030 and this is ending it as a public

health threat we need to focus on the three key groups where HIV continues to be a major challenge and those three groups are men who have sex with men in particular younger men who have sex with men, in particular younger men who have sex with men,

injecting drug users, and in Africa young women.

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