HIV strains in India resist some broadly neutralising antibodies

What are bNAbs?

• HIV changes its shape a lot, so ordinary antibodies usually fail.

• Some special antibodies, called broadly neutralising antibodies (bNAbs), can attack HIV at places the virus cannot easily change (like its “weak spots”).

• Scientists want to use these bNAbs in treatments or vaccines.

The challenge

• HIV has many subtypes and each has many strains (like different versions of the same virus).

• One bNAb may work well on some strains, but not all.

• This makes it hard to find a “one-size-fits-all” antibody.

The new Indian study

• Researchers tested 14 of the world’s best bNAbs on HIV strains from India and compared them with South African strains.

Findings for India:

• Antibodies that target the V3 glycan region = worked best.

• Antibodies against the CD4 binding site = worked fairly well.

• Antibodies against the V1/V2 apex = did not work well (Indian strains resisted them).

• If a virus resisted V1/V2 antibodies, it was often easily stopped by CD4-site antibodies.

 Proposed solution

• A cocktail of three antibodies (BG18, N6, PGDM1400) could together block most Indian HIV strains.

• Using a mix is better than relying on a single antibody because the virus cannot escape all of them at once.

Regional differences

• Indian HIV strains were:

  • More sensitive to N6, 10-1074, BG18

  • Slightly resistant to CAP256-VRC26.25

• South African strains behaved differently.

• Reason: small structural changes in the virus in each region.

Why does it matter?

• Shows that HIV therapies and vaccines cannot be identical worldwide.

• We need region-specific strategies:

  • Example: India may need a different antibody mix than South Africa.

• Suggests regular monitoring of HIV strains so treatments can be updated.