SACRAMENTO (AP/CBS13) – Even as shortages remain, California is getting ready to expand its list of people eligible for the COVID-19 vaccine.

State Health Director Dr. Mark Ghaly said Friday that starting March 15 people between the ages of 16-64 who either severely disabled or have health conditions that put them at high risk can get in line for shots.

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This would mean some 4 to 6 million more Californians would be eligible for the vaccine.

California has been plagued by vaccine shortages and Ghaly acknowledged he’s not sure how long it will take for the federal supply of shots to meet demand.

The state’s decision to rely largely on age for vaccine eligibility was criticized by those who said it failed to protect people under 65 and at high risk of infection and death from COVID-19.

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Ghaly said there are roughly 13 million people already eligible for vaccination, including health care workers. The new additions will push the total to nearly half the state’s population of just under 40 million.

California has opened many mass vaccination centers in the last several weeks but they aren’t operating close to full capacity because of vaccine shortages. The city of Los Angeles temporarily closed vaccination sites at Dodger Stadium and four other locations until supplies could be replenished.

More from CBS Sacramento:

Two shots are required for each person to be fully vaccinated. California has administered 5.5 million doses to date, and more than 1 million people have gotten both.

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Copyright 2021 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.