Biden ramps up COVID-19 vaccine production as states start lifting restrictions.

To help ramp up vaccination efforts, the pharmaceutical company Merck has agreed to help mass-produce Johnson and Johnson's single-dose coronavirus vaccine. President Biden now says there will be enough doses for every adult in the country by the end of May. CBS News correspondent Janet Shamlian reports from Houston, and Dr. Dara Kass, an ER doctor and medical contributor for Yahoo News, joins CBSN's Elaine Quijano to discuss the latest.

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