Doctors are reporting a California baby born with the Aids virus may have had her infection put into remission and cured by very early treatment.
It is the second instance of early treatment that may have cured a baby born with HIV.
Doctors worldwide are now rethinking how to treat infants born with the virus, Radio New Zealand's correspondent in the US reports.
The baby girl was born in Los Angeles in April last year to an HIV positive mother who was not taking her medication.
Doctors say the mother was given Aids drugs during Labour to try to prevent transmission of the virus and her baby was given them starting four hours after birth.
Tests later confirmed the baby had been infected, but does not appear to be now nearly a year later.