Del/DelTwo copies of the CCR5-delta32 deletion — this well-studied variant removes the CCR5 co-receptor most HIV-1 strains use to enter immune cells. Published research associates this genotype with strong natural resistance to infection by most HIV-1 strains. This is a rare genotype, most common in Northern European populations.
Ins/DelOne copy of the CCR5-delta32 deletion. Published research associates this genotype with somewhat slower HIV-1 disease progression if infected, but not resistance to infection itself.
Ins/InsNo copies of the CCR5-delta32 deletion. Typical CCR5 receptor expression.
This variant does not protect against all HIV-1 strains (some use a different co-receptor) or against other sexually transmitted infections. It is not a substitute for standard prevention.
Source: Samson et al. 1996, Nature — resistance to HIV-1 infection in Caucasian individuals bearing mutant alleles of the CCR5 chemokine receptor gene.