By Megan Hickey

CHICAGO (CBS) — The United Center vaccine registration website has gotten a lot of traffic. At one point Sunday it was getting 300,000 hits per minute. Monday the city addressed some, but not all, of the reasons for glitches in the system.

The tents are up, and the 101st Airborne Division soldiers are on deck as crews are making sure the FEMA-run site with a capacity to administer 6,000 vaccine doses per day is ready for the onslaught of patients.

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Kint Wong secured an appointment for his wife on Wednesday — an appointment so precious that he went two days early to get the lay of the land.

Fortunately he wasn’t in the group of users who found the registration process utterly confusing.

Cancellation emails in particular are to blame. Some confirmed patients got four emails in a period of less than 12 hours telling them they had been rescheduled and then that the rescheduling email had been sent in error.

“We do apologize obviously for that email,” said Dr. Allison Arwady, commissioner of the Chicago Department of Public Health.

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On a press phone call Dr. Arwady couldn’t say exactly why there was a glitch or how many people were affected. She said others received error messages for fibbing about their age.

“There were a lot of people who attempted to sign up, saying that they were over 65 and then when they provided a date of birth, they were not 65 or older, and those appointments were cancelled,” she said.

The United Center is far from the only site experiencing technical glitches. Computer scheduling errors have plagued systems in California, New York and Georgia.

There seem to be few complaints so far about registration at the drive through clinic at the Indianapolis Motor Speedway.

“It’s great. I mean really convenient,” said Darryl Allen, who was getting his vaccine. 

But that clinic was only set to last four days.

The United Center is slated to stay open for eight weeks.

Zoc Doc also tweeted out an apology Sunday saying, “We understand that some users had difficulty booking vaccinations at Chicago’s United Center this afternoon.” 

They said that as of Sunday night the issue had been resolved.

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Dr. Arwady said that if in doubt, those users should go by the time listed on the Zoc Doc website. Those times should be accurate.

Megan Hickey