Scientists now report that Treg cells, a type of regulatory lymphocyte, may be protecting babies in the womb from getting infected with the HIV virus when the mother is affected. “Even though the number of babies studied is relatively small, these findings indicate that Treg, by controlling immune activation, may lower the vulnerability of the babies to HIV or other chronic infections even before they are born. Finding out what protects the majority of babies is important, as it can lead to ways to boost natural immune responses and make individuals resistant to HIV infection,” said Kessler. These results could pave the way for the development of vaccines or other immune-based therapies that prevent the spread of HIV or other infections from mothers to their babies.