Irvine lab researchers developed a two-dose regimen that could make HIV vaccines more effective. In a study appearing in Science Immunology, the team reduced a schedule of seven escalating doses over two weeks to just two doses over one week. The new regimen is more practical for mass vaccination campaigns, but was similarly effective in mice at promoting strong antibody responses that will be critical for a successful HIV vaccine. The study uncovered biological mechanisms behind the vaccine response that could inform ongoing clinical trials and development of vaccines for other diseases.