A: Group testing!
Simply put, you combine several samples and test them all at once. If the combined sample comes back negative, you know that all the patients in that group do not have COVID-19. If it comes back positive, you go back and do individual tests on the same samples.
This group-testing strategy is most effective at making limited supplies last longer when the prevalence of the disease is low, because a smaller percentage of the group tests will come back positive.
Links:
For more on COVID-19 testing supply shortages:
