Half of US adults have received at least one dose of the COVID-19 vaccine and about a third are fully vaccinated, according to new data from the Centers for Disease Control and Prevention.

Why it matters: COVID-19 cases and hospitalizations are still on the rise, CDC director Rochelle Walensky said during Friday's White House COVID-19 briefing. With cases in many states being driven by variants, public health officials have emphasized the need to ramp up vaccinations.

Details: For Americans over 18 years of age, 50.4% have received at least one COVID-19 vaccine dose, and 32.5% are fully vaccinated.

• Among seniors 65 and older, 81% have received at least one dose and 65.9% are fully vaccinated.

At Friday's briefing White House COVID-19 Response Coordinator Jeff Zients noted that in the past week the U.S. vaccinated roughly 3.3 million people per day, an increase on the seven-day average from the previous week.

• He also added that the U.S. is on track to "meet or beat" President Biden's goal of administering 200 million vaccine doses in the first 100 days in office.