A key part of the problem is a lack adequate infrastructure and investment.
The organization wants to vaccinate 70% of the world by mid-2022, but says there's not nearly enough funding to make that happen.
Dr. Larry Brilliant, who helped stop smallpox, urges nations to work together to prevent further COVID spikes and equalize vaccinations.
The administration's actions are expected to weaken the global health organization during the coronavirus pandemic and escalate tensions with China.
The organization's ability to tackle disease globally is hampered by under-funding.