Why Novavax is the "dark-horse" COVID-19 vaccine

Between the lines: Novavax has never brought a product to market before, and began last-state clinical trials months after some of the other candidates.

• But AstraZeneca's rollout has been plagued by a series of public relations mishaps, and it — along with Johnson & Johnson's shot — has been linked to rare but serious blood clots. J&J is also facing production concerns in the U.S.

By the numbers: Novavax has committed to provide 100 million doses of its shot to the U.S. later this year, and has promised to provide 1.1 billion doses to low- and middle-income countries.

• The U.S. probably doesn't need any more vaccines. But the rest of the world does.

What we're watching: Whether the company can ramp up manufacturing enough to meet its ambitious goals.

• "If that [would] face a challenge, it would be a big setback for COVAX in terms of delivering doses in 2021," Mesfin Teklu Tessema, senior director at the International Rescue Committee and a member of a civil society working group for COVAX, told Politico.