Suburban Cook County will join the rest of the state outside Chicago in expanding coronavirus vaccine eligibility Monday to everyone 16 and older as the state makes 150,000 appointments for first doses available for next week at mass vaccination sites and pharmacies in the suburbs.

Most of Illinois’ 101 other counties already have expanded eligibility to everyone old enough to receive the vaccine, but the city of Chicago, which gets its own supply from the federal government, isn’t following suit until April 19, the most recent deadline President Joe Biden set for universal adult eligibility.

Meanwhile, the University of Chicago is reporting at least 50 COVID-19 cases involving undergraduates, officials announced Thursday. New restrictions are being imposed, including a stay-at-home order and a halting of in-person classes.

Recent tests detected more than 50 cases involving students, including many who are living in residence halls, according to a written statement from the school, located in the Hyde Park neighborhood. Officials warned they “expect this number to increase.”

Here’s what’s happening Friday with COVID-19 in the Chicago area:

7:41 a.m.: Walgreens allowing people awaiting second doses of Pfizer vaccine to reschedule appointments

People who received their first doses of the Pfizer COVID-19 vaccine at Walgreens may try to reschedule their second dose appointments — which were otherwise scheduled for four weeks after the first ones — for slightly earlier dates, a Walgreens spokesman said Thursday.

Once 20 days have passed since the first dose, people may try to reschedule the next shot for an earlier date, said spokesman Jim Cohn.

Earlier this week, the Centers for Disease Control and Prevention asked Walgreens to start spacing first and second doses of the Pfizer COVID-19 vaccine three weeks apart instead of four, in line with the agency’s guidance. Walgreens had been scheduling appointments four weeks apart, regardless of whether they received Pfizer or Moderna vaccines.

The CDC recommends 28 days between first and second doses of the Moderna vaccine, but 21 days between doses of the Pfizer vaccine.

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