Just one month ago, US President Joe Biden and his health advisers announced big plans to soon deliver a booster shot of the coronavirus vaccine to all Americans.

But after campaigning for the White House on a pledge to "follow the science", Biden found himself uncharacteristically ahead of it with that lofty pronouncement.

Some of nation's top medical advisers have delivered a stinging rebuke of the idea, in essence telling the White House: not so fast.

A key government advisory panel overwhelmingly rejected Biden's plan to give Covid-19 booster shots across the board and instead recommended the extra vaccine dose only for those who are age 65 or older or who run a high risk of severe disease.

Read more from AP here.