The immune response of the fetus differs from that of the newborn as well because cells from the mother move across the placenta and enter the fetus. “The fetus doesn’t want to make an inflammatory response against mother,” McCune says. “So the fetus has developed an immune system that says ‘do not respond.’” That calming of the immune response may hold over to the first few days of the newborn’s life; the inflammatory response does not fully activate, robbing the new HIV infection of additional fuel. This delay, combined with a short course of aggressive treatment, may give the body enough of a head start to eradicate the virus on its own, he notes.
“It’s very exciting,” McCune says. “Many revolutions in medicine have occurred because of a single case.”
Mofenson cautions that the result from the Mississippi case does not mean that clinicians and pediatricians should change any of their practices yet. Even children or older patients with very low viral load levels should continue antiretroviral therapy. There are “multiple questions raised by this case that really need urgent and further research.” To that end, her institute has put out a call for research proposals. “Now people are aware of this and can bring other children to our attention,” she says. “Hopefully, within a year or two we will have better answers.”