In another sign that vaccine supply is outpacing demand, Harris County Judge Lina Hidalgo on Monday announced that the county-operated mass vaccination site at NRG Park will no longer require appointments and will instead accept anyone 16 years or older who shows up.

The NRG Park site, which administers the two-shot Pfizer vaccine, was set up by FEMA earlier this year and is among the largest in the country. In the two months since the NRG site opened, Harris County Public Health has administered more than 500,000 doses — more than 20% of vaccines given out in Harris County as a whole, according to Hidalgo.

But as the number of vaccines allocated has increased, the number of people looking to get vaccinated has not kept pace, Hidalgo said. 

“Demand hasn’t just caught up with supply,” she said “There is more supply than there is demand.”

People can either drive or walk up to Gate 16A off Main Street, between 8 a.m. and 5 p.m. Tuesday, and between noon and 9 p.m. starting Wednesday, Hidalgo said.

The announcement comes just three days after Harris County opened up 55,000 “on demand” vaccination appointments, moving away from a priority list and instead instituting a first-come, first-served approach similar to Houston’s.

Hidalgo has also blamed the gap between supply and demand on “vaccine hesitancy,” and in particular possible community concerns after the U.S. Food and Drug Administration and Centers for Disease Control and Prevention recommended providers pause usage of the one-dose Johnson & Johnson vaccine.

That recommendation was out of “an abundance of caution” after six people of nearly 7 million people developed a rare blood clot disorder — roughly 0.00000088% of all patients.

“Some people only wanted the Johnson & Johnson vaccine, so they’re waiting to see if the pause will be lifted,” Hidalgo said.

Just about 25% of all eligible Harris County residents have been fully vaccinated, Hidalgo said. Researchers believe anywhere from 75-80% of the community would need to be vaccinated in order to reach herd immunity.

The NRG site was at one point able to consistently vaccinate 6,000-7,000 people a day. Last week, that number dropped by about half, Hidalgo said.

“Over the weekend, and even today, we’re seeing very low numbers that show us we’re leaving vaccines on the table,” Hidalgo said. “We’re leaving this resource unused.”

The Houston Health Department on Monday also confirmed it was encouraging its locations to accept walk-ins after a drop in demand, according to department Director Stephen Williams.

“A fair part of it is related to the Johnson and Johnson news, but what we’ve also observed when we’ve gone into the field, is that people really want to have the vaccine more convenientely located to them,” Williams said. “When our people have gone door to door in certain neighborhoods, and folks found out that the vaccine was available a short drive away, they seemed a little bit more willing to get the shot.”