Over 4,500 Santa Clara County residents didn't show up for vaccine appointments they made last week, during the first week of Levi's Stadium being operational, prompting calls for the county to set up waitlists and make sure that no vaccine doses go to waste.

About 10% of people making vaccination appointments at county-run sites have been no-shows thus far in the process, as officials tell NBC Bay Area. And without an existing waitlist, a now familiar scenario played out at the Santa Clara County fairgrounds on Saturday. Officials realized that, due to no-shows, they had 300 doses that were thawed and would otherwise go to waste, and so emails, phone calls, and texts went out to county employees, telling them to come line up and get shots if they wanted them.

Some doses were given to members of the public as well.

It's unclear whether vaccine was unnecessarily thawed at Levi's Stadium also, but NBC Bay Area reports via county officials that there were 4,517 no-shows across the county between February 8 and February 12 — a large portion of which would have been Levi's Stadium appointments. County officials says this represented 10% of the total number of appointments made countywide.*

The county says the no-show rate is likely due to people scheduling more than one appointment, for fear that one might be canceled — a slew of appointment cancellations have happened in Santa Clara County and elsewhere in recent weeks due to interruptions in the vaccine supply.

County officials say that no doses went to waste at Levi's, despite the no-shows.

Dr. David Magnus, the director of the Stanford Center for Biomedical Ethics, tells NBC Bay Area that this pattern is going to continue and it's inexcusable for counties not to have mitigation plans in place — waitlists and other means of giving out extra vaccine once it's thawed.

"Having a waitlist available and a plan to mitigate the problem so you don’t have good doses left over and little time to deal with it," Dr. Magnus said.

Situations like this have been occurring around the country, allowing young and healthy people to jump ahead of official queues and get their first doses — after which second doses are typically guaranteed.

In one instance in early January, a hospital in Ukiah had a freezer fail where a batch of 850 vaccine doses was being stored, and doctors realized they had just a couple of hours before the vaccine became non-viable due to being thawed. A scramble ensued in which hundreds of local residents lined up to get their first shots ahead of most of the state.

Photo: Ash Kalra/Twitter

*This post has been corrected to clarify that the 4,517 missed appointments were countywide, and not just at Levi's Stadium.