VACCINES made from live but weakened HIV could wipe out AIDS in countries
such as Thailand and Zimbabwe within fifty years, computer models suggest. But
there’s a big catch: such vaccines will inevitably kill some of the people
they’re meant to protect.
Live “attenuated” vaccines made from weakened forms of viruses work much
better than vaccines containing inactivated viruses. But they are inherently
risky—sometimes the weakened virus itself causes disease, or reverts to
the wild-type form.
Tests in monkeys suggest live HIV vaccines could work in humans, but their
use is controversial. “HIV strikes at the heart of the…
