Regions containing putative mutations were PCR amplified using oligonucleotide primers listed in Additional File 2. They were then purified using Qiaquick (Qiagen) and sequenced using Sanger sequencing. Sequence differences were confirmed by manual examination of the trace data. Antibody-Based HIV-1 Vaccines: Recent Developments and Future Directions: A summary report from a Global HIV Vaccine Enterprise Working Group The authors discuss humoral immune responses to HIV and approaches to designing vaccines that induce viral neutralizing and other potentially protective antibodies. T he Global HIV Vaccine Enterprise convened a two-day workshop in May of 2007 to discuss humoral immune responses to HIV and approaches to design vaccines that induce viral neutralizing and other potentially protective antibody responses. The goals of this workshop were to identify key scientific issues, gaps, and opportunities that have emerged since the Enterprise Strategic Plan was first published in 2005 [1] , and to make recommendations that Enterprise stakeholders can use to plan new activities.