In a shift away from next-generation Covid-19 vaccines, the Trump administration is investing $500 million in a vaccine project championed by two scientists who were recently tapped to serve in senior roles within the National Institutes of Health,

The potential change outlined in a statement would require all new vaccines to undergo placebo testing, sparking concerns among medical experts.

Health and Human Services Secretary Robert F. Kennedy Jr. is changing the way vaccines are tested. The department will now require all new vaccines to undergo safety testing in placebo-controlled