Per petitfour's link in comment# 10:
The infant underwent remission of the HIV infection after receiving antiretroviral therapy (ART) within 30 hours of birth Zidovudine, Lamivudine and Nevirapine. A series of tests showed progressively diminishing viral presence in the infants blood until it reached undetectable levels 29 days after birth. Gay switched Nevirapine with Kaletra for long term therapy.
Thank you for the additional information, neverdem. Now I know a bit more about the drug mechanisms.
These drugs work in different ways to prevent the virus from making new virus particles. Normally, they would prevent the spread of virus to uninfected cells, putting the HIV in stasis. Infected cells remain infected, although they can be killed and removed by the immune system if it is functional and able to recognize them as infected.
I wonder if anyone is doing a genetic analysis of the little girl's immune system? It would be interesting to see if she has a variant known to decrease people's chance of becoming infected.