Provided herein are HIV vaccines that encompasses recombinant trimers that mimic native HIV-1 envelope trimers. Also provided are methods of administering to a subject in need thereof an HIV vaccine provided herein to elicit antibodies against a recombinant trimer in the subject. A recombinant trimer is formed by a recombinant protein comprising a recombinant HIV-1 gp140 fused to a tag through a linker at C-terminus of the recombinant HIV-1 gp140, wherein the linker is sufficiently long so that the tag is accessible for binding by a binding molecule bound on a solid matrix during purification of the recombinant trimer.