A Third Of U.S. Population Has Received 1 Dose Of A COVID-19 Vaccine

President Biden has moved the deadline for all American adults to be eligible for a COVID-19 vaccine to April 19th, two weeks earlier than initially planned. However, the emergence of new COVID variants and an increase in infections pose new challenges in combating the pandemic.

What percentage of those aged 65 and older is mentioned in the text?

What is the new deadline for all American adults to be eligible for a vaccine?

How much earlier is President Biden moving the vaccine eligibility deadline compared to the initial deadline?

What challenges are mentioned in relation to the pandemic fight?

What factors are contributing to the fresh challenges in the pandemic fight?