Jennifer Couzin-Frankel

Lecanemab slows speed of cognitive decline, but possible links to serious brain hemorrhages concern many scientists

Risk of heart inflammation is small but new studies suggest it may take months to fully recover

Five lupus patients given genetically modified versions of their own immune cells show vast improvement

Initiative focuses first on hypothesis that coronavirus lingers in patients

Efforts are underway to blunt immune complications that come with lifesaving treatment

Abnormal immune response, lingering virus, and blood clots all under investigation

Project can draw on more than 250 million people for COVID-19 vaccine research

Selecting embryos based on such screening is premature, other researchers warn