Identification of a safe and effective prophylactic vaccine to prevent HIV-1 epidemic is among the highest priorities in HIV/AIDS research. A major obstacle for HIV-1 vaccine development is virus diversity which continues to increase due to high mutation rates and recombination. My laboratory is interested in developing a multi-valent anti-HIV vaccine with a large number of envelope recombinants generated through an unique yeast based recombination system, as well as various primary envelopes. We hope this strategy will successfully circumvent the HIV-1 enormous genetic diversity and lead to an effective anti-HIV vaccine. In related to HIV vaccine development, we are also working on HIV diversity, recombination, and finding novel broadly neutralizing anti-HIV antibodies.