While some may shriek at the idea of exporting the West’s problematic med tech to the Third World, others argue it’s better than nothing. P24-antigen tests may hit big in poor parts as a cheapish way to check not only if an HIVer should start combo therapy but how well it’s working. The test measures p24 antigen, a protein in the core of HIV, which, in turn, indicates how much virus is in the blood. Its virtue is cost: $20 to $30 per, compared to $152 for a standard viral-load test. Its vices: p24 is essentially a surrogate for a surrogate (HIV RNA) and so is not nearly as accurate as the rich-world way.