BBC News - Smallpox demise linked to spread of HIV infection: "Experts say the vaccine used to wipe out smallpox offered some protection against the Aids virus and, now it is no longer used, HIV has flourished.
The US investigators said trials indicated the smallpox jab interferes with how well HIV multiplies.
But they say in the journal BMC Immunology it is too early to recommend smallpox vaccine for fighting HIV."
