Global disease experts say little is known about China's experience with long-term COVID effects thought to have afflicted millions with debilitating fatigue, brain fog and other symptoms
The doses for Bangladesh will arrive on Monday, the official said.
The doses are part of President Joe Biden's promise to share doses of US vaccine with other countries around the world, via COVAX or directly.
"Scientific teams and legal and regulatory authorities from both countries have worked together to ensure the prompt delivery of safe and effective vaccine lots," the official said.