For reasons not completely understood, VHH are very good in neutralizing viruses. While the development of a vaccine against HIV1 is still not successfully completed, immunization of Llama with gp41, gp120 and gp 140 envelop proteins all resulted in VHH that neutralizes HIV1 to a certain degree even up to 95% neutralization.
Within the frame work of the GATES project .. and the EU projects EMPRO and CHAARM Univ. College London, UU and QVQ have selected over 100 VHH against HIV1 and have determined together with EMBL Grenoble and NIH Bethesda the exact epitopes recognized by these VHH. Details of this work will soon be published.