INDIANAPOLIS — Facing high demand and a national shortage of rapid tests, the Indiana Department of Health announced changes to its testing procedures Tuesday.

The department will extend hours at the community testing and vaccination clinic outside the Indianapolis Motor Speedway. The new hours effective immediately, will be 12 p.m. to 8 p.m. Tuesday through Friday and from 8 a.m. to 4 p.m. on Saturdays through Jan. 22.

The clinic, which is being held in the IndyCar parking lot at 4551 W. 16th St. across from Gate 2, will accept walk-ins only from noon to 4 p.m.

Patients can get the two-dose Pfizer pediatric and adult vaccines as well as the two-dose Moderna vaccine.

The big change involves rapid tests and who’s eligible to get them. The state health department is now offering rapid tests only to people 18 and under and symptomatic individuals ages 50 and over.

From the department:

This change is necessary due to the national shortage of rapid antigen tests and is designed to help ensure that students can stay in school and that Hoosiers who are most likely to need a monoclonal antibody are identified within the prescribed window in which they can be administered.

Typically, Indiana goes through about 50,000 rapid tests per week. However, the state is only guaranteed to receive 11,000 a week for the time being, prompting the change in testing protocol.

The state will still honor appointments for rapid tests scheduled for Tuesday. No appointments for rapid tests will be honored at state or local health department sites going forward unless an individual meets the new criteria.

The state said PCR tests, which are processed in a lab and are considered the “gold standard” in testing, will continue to be offered at all testing sites. Results for PCR tests are expected within two or three days.