WASHINGTON, June 3 (Reuters) - U.S. Health and Human

Services Secretary Robert F. Kennedy Jr. said on Tuesday that

Moderna ( MRNA ) has agreed to a true placebo-controlled trial of its new

COVID-19 vaccine.

While noting that he was aware of concerns about the Food

and Drug Administration's limited approval of the new mRNA

vaccine for high-risk populations, Kennedy assured the agency

will monitor and collect data throughout the trial for every

adverse outcome.