Trump’s HHS and NIH are planning to invest $500 million in a killed-whole-virus approach to universal vaccines, including such vaccines for flu and COVID. Here’s why that’s challenging

The top US health department plans to require placebo testing for all vaccines in an effort to offer "straightforward" public health information, but experts say such testing could limit availability and raise ethical concerns.

The influx of cash comes as the nation’s health agencies cut grants, staff and budgets.