[deepakINdc]

Several valid points already made here:

1. Phase 1 is for safety 2. 30 is a small number

But the big issue here is the reason HIV and even the common cold is hard to treat -- high turnover and high rates of mutation.

So, even if you have Ab's and/or helper T cells (cell that remember an infection) against one or more strains of HIV, the presentation of the strain that an individual may pick up later on in life may be different and thus might not mount an immune response. Also of interest -- Helper T-cell sare the primary target of HIV.

In order to really determine if or not this vaccine is effective, we will have to observe the responses in people who have been given the vaccine and then contracted HIV later in life. While this is promising and will add another barrier against HIV, its unlikely to eradicate the virus.