Researchers are striving to understand the impact a phenomenon known as original antigenic sin has on immunity to the virus.
The 19th on MSN

What The 19th loved in 2025

For five years, The 19th staff has taken time to pause and reflect on the things that brought us joy over the past year — ...
Ryu Lopez is quite literally a miracle baby. Ryu developed completely outside his mother's uterus, resting on his mother's ...