COVID-19 updates: Pfizer vaccine highly effective in children 5-11

The U.S. has now donated and delivered 200 million COVID-19 vaccines globally, according to a White House official.

The figure is part of 1.1 billion doses President Joe Biden has pledged to more than 100 countries around the world. 

"These 200 million COVID-19 vaccine doses have helped bring health and hope to millions of people, but our work is far from over," Samantha Power, administrator for the U.S. Agency for International Development, which is assisting in the global vaccine effort, said in a statement. "To end the pandemic, and prevent the emergence of new variants, as well as future outbreaks within our nation’s borders, we must continue to do our part to help vaccinate the world."

The Biden administration has received criticism for getting Americans booster shots while many around the world have yet to get one. Though the White House has insisted the U.S. can provide boosters to its citizens while funneling doses overseas -- and working to increase vaccine production abroad.

-ABC News' Ben Gittleson

Forecast models used by the CDC are predicting that weekly COVID-19 death totals in the U.S. will likely continue to drop in the weeks to come, though thousands of Americans are still expected to lose their lives to the virus.

The model expects approximately 18,000 deaths to occur in the next two weeks, with a total of around 757,000 deaths recorded in the U.S. by Nov. 13.

The ensemble model estimates that 19 states and territories of the U.S. have a greater than 50% chance of having more deaths in the next two weeks compared to the past two weeks, and that four states and territories (Alaska, Nebraska, Ohio and American Samoa) have a greater than 75% chance of an increase over the next two weeks.

-ABC News' Arielle Mitropoulos

The FDA authorized booster shots for the Moderna and Johnson & Johnson vaccines for some populations Wednesday.

Moderna's vaccine can be administered at least six months after the second dose for people ages 65 and up and those ages 18 through 64 who either are at high risk of severe COVID-19 infection or have occupational exposure to the virus, the FDA said.

The J&J booster can be administered at least two months after the single-dose shot to those ages 18 and up, the agency said.

The FDA, which authorized Pfizer's booster dose last month, also said it will allow people to mix booster doses.

-ABC News' Anne Flaherty and Eric Strauss

In the United Kingdom, cases are up 16% since last week, officials said Wednesday. As winter nears, Health Secretary Sajid Javid warned that infections could go as high as 100,000 per day.

Deaths, however, remain low in the country. Officials are encouraging residents to get booster shots.

-ABC News' Joe Simonetti