The White House announces the United States will ship an additional 20 million doses of Covid-19 vaccines worldwide, a CDC study finds Pfizer/BioNTech and Moderna's Covid-19 vaccines are 94% effective in health care workers, and more.

• Sanofi and GlaxoSmithKline (GSK) on Monday announced results from their Phase II clinical trial of the companies' joint Covid-19 vaccine, saying the trial found the vaccine developed a strong antibody response in participants of all ages. After two doses of the vaccine, participants in the trial showed an antibody response similar to those who had recovered from Covid-19, according to the results. Sanofi and GSK said they plan to start late-stage trials and production within the coming weeks, with the aim of having the vaccine authorized for use by the end of the year (Branswell, STAT News, 5/17; Associated Press, 5/17).

• White House press secretary Jen Psaki on Monday announced the United States will send 20 million doses of Covid-19 vaccines to other countries by the end of June. This comes in addition to the 60 million doses of AstraZeneca's vaccine—which has not been authorized in the United States—that the U.S. said it will export. Psaki didn't say where the donated vaccines will go, rather that the decision will be made once it receives FDA clearance. "We know America will never be fully safe until the pandemic that's raging globally is under control," President Joe Biden said. "No ocean's wide enough, no wall's high enough, to keep us safe" (Chen, Axios, 5/17; Breuninger, CNBC, 5/17; Stolberg/Slotnik, New York Times, 5/17; Wise, NPR, 5/17).

• The Covid-19 vaccines developed by Pfizer/BioNTech and Moderna were both found to be highly effective among health care workers, according to interim results from the largest CDC study on the vaccines' efficacy to date. The study included 1,843 health care workers at 33 sites across 25 states, who participated between January and March. According to the results, fully vaccinated health care workers were 94% less likely to develop a symptomatic case of Covid-19, while partially vaccinated health care workers were 82% less likely to develop symptomatic Covid-19 (Coleman, The Hill, 5/14; Anderson, Becker's Hospital Review, 5/14; Anthes, New York Times, 5/14).

• FDA is currently holding more than 100 million shots of the Covid-19 vaccine developed by Johnson & Johnson for further testing after the discovery of multiple safety violations at an Emergent BioSolutions plant in Baltimore, Emergent CEO Robert Kramer told a House panel on Wednesday. Kramer said Emergent has "made significant progress" on the problems FDA cited, which included unsanitary conditions and workers' lack of adherence to certain operating procedures. "We are very close to completing them and now expect we'll be in a position to resume production within a matter of days" (Lovelace, CNBC, 5/19; Loftus, Wall Street Journal, 5/19; Owermohle, Politico, 5/19).

• FDA has said the Covid-19 vaccine developed by Pfizer/BioNTech is now able to be stored at normal refrigerator temperatures for up to a month, a change the agency said would make the vaccine easier to store and distribute. Previously, the vaccine in an undiluted and thawed state could be stored at refrigerator temperatures—between 35 degrees and 46 degrees Fahrenheit—for no more than five days (Schemm et al., Washington Post, 5/20; Greenhalgh, NPR, 5/19).