Wednesday's announcement that all Americans will be eligible for COVID-19 boosters eight months after their second dose was met with skepticism at home and opposition abroad.

Driving the news: Many public health experts criticized the decision as premature or even unethical, and that eight months is too long — vulnerability can return as soon as five months after the second dose.

• The WHO slammed the U.S. for planning third shots while so many around the world haven't had their first.

Starting Sept. 20, Americans who received the Pfizer or Moderna vaccine should expect to be offered a third dose.

• On the J&J vaccine, Biden health officials say they're waiting for more data before making the recommendation for a booster shot.

The big picture: There's still a global shortage of vaccines, and the announcement will only increase the pressure on the U.S. to do more to vaccinate the rest of the world.

• Physicians and medical ethicists say it's difficult to justify a third dose for relatively healthy people given the global need.