HIV/AIDS vaccine development: are we walking out from the dark?

The need for AIDS vaccine has been emphasized by the increase of HIV-1 prevalence in sexual transmission which bridges the spreading of HIV-1 from high-risk population to other populations. After more than two-decade intensive effort on the AIDS vaccine development it remains elusive whether and how an effective vaccine will be achieved. Recent data released from a phase III trial in Thailand showed a partial protection might be accomplishable by the "prime-boost" combination of two vaccines: ALVAC® HIV vaccine (the prime) and AIDSVAX® B/E vaccine (the boost) This unprecedented large clinical trial observed that the prime-boost combination lowered the rate of HIV infection by 31.2% compared to placebo based on the modified intent-to-treat population (n=51 vs. n=74 respectively; P=0.04). However debating on the efficacy interpretation of this trial arose among field scientists. Furthermore how to improve the efficacy will become the most important question to be tackled. Here we reviewed the recent publications and summarized the major progress achieved.