Novavax Inc. on Aug. 5 again delayed the company’s timeline for seeking U.S. authorization for its two-dose Covid-19 vaccine, but expects to become a major distributor to lower and middle-income countries this year.

German biotech CureVac NV said the company’s Covid-19 vaccine was only 47 percent effective in a late-stage trial, missing the study’s main goal and throwing in doubt the potential delivery of hundreds of millions of doses to the European Union.

The Biden administration plans to donate 500 million Pfizer coronavirus vaccine doses to nearly 100 countries over the next two years, three sources familiar with the matter told Reuters on June 9.

COVAX will deliver 237 million doses of AstraZeneca’s Covid-19 shot to 142 countries by the end of May as the World Health Organization-backed program steps up the global roll-out of its vaccine supplies.