About 5,200 people received their first COVID-19 shots Wednesday at the Rio Rancho Events Center, but a number of them had to wait in line for hours.

Walgreens ran the event, and leased the center in conjunction with the state Department of Health, said Mayor Gregg Hull. The city, Sandoval County and Central New Mexico Community College played support roles, according to the county.

“While, yes, there were delays and inconveniences (Wednesday), I don’t want that to overshadow the fact that there were hundreds of health-care workers and volunteers that worked from sunup to well after sundown at this event to vaccinate as many people as they could,” Hull said. “And for that, I say thank you.”

He said the 5,200 shots given made the event the largest in Sandoval County, and possibly the biggest in the state, so far.

Based on lessons from Wednesday, Hull said the city wouldn’t allow single-day vaccination events for 5,000-plus people at the center again. He said the booster shots for people immunized Wednesday would be given over two days.

“So the delays experienced at this event won’t be experienced with the booster shot,” Hull said.

The city will also consider an outdoor vaccination facility.

Rio Rancho Events Center has hosted five previous vaccination events for 1,000 to 3,000 people without backlogs, he added. It was the 5,200 people than strained the system.

Hull believes Wednesday’s backups started when people without appointments or registration in the state vaccination system showed up.

“When you’re already trying to move 5,000 people through the system, you throw in a couple thousand more cars and you’ve got a bit of a mess,” Hull said.

He said it’s understandable people would drop by without appointments because many of them see the vaccine as a “door to a normal life.”

“We’re all struck with COVID fatigue,” Hull said.

He wants to continue using the Events Center for vaccinations. It’s more convenient for county residents than locations in Albuquerque or beyond, and nowhere else in the county can handle as many people, he said.

Getting 5,200 people vaccinated was a win for Sandoval County, Hull said, even with the delays.