They call them Eureka moments. A scientific advance that comes like a bolt from the blue. They don't often happen in Mississippi, but this one did - and it came purely by accident.
An HIV-positive mother had a child. She didn't know she was HIV positive until the results of some tests during labour.
If doctors had known they would have given her antiretroviral drugs before labour to reduce the load of HIV in her blood and reduce the risk of passing it on to her baby. But it was too late for that.
Normally they would have started the baby on an antiretroviral drug soon after birth to combat HIV.
But in this case, the baby's mother had no pre-natal treatment so they decided to go large and gave the baby THREE different drugs simultaneously 30 hours after birth. They thought the child would be on these drugs for the rest of its life.
And so it would have been. But the mother started missing appointments at the clinic. They didn't see her for five months and the infant got no drugs.
So when they did see the baby again, aged 23 months, they expected tests to show high levels of HIV.
They didn't - the child had no measurable infection.
That's the Eureka moment - the treatment they had improvised for this child had worked spectacularly well. Wow.
Could it work for other children? Could three drugs soon after birth become a successful standard treatment?
Here's where we need some caution. It may be that this child still has HIV infection somewhere in the body which isn't being measured by the tests.
It could be that there is something special about this child that protects against HIV. But if there is, researchers should be able to find out what and that could be the basis of a new treatment.
Of course, all that will have to be done. And there will have to be careful trials of any new treatment.
Luck may have shown the possibilities, but doctors can leave nothing to chance in exploiting them.