Vacuums come in several varieties, and one key distinction between machines is if it’s a bagged vacuum or a bagless vacuum. Both are capable of removing debris, dirt, and allergens. For bagged vacuums, one benefit is that “you can get high-efficiency filter bags that would prevent many of the allergens from coming back out of the exhaust,” says Dr. McGrath. But this option can be more costly for users because it requires the purchase of new bags. “Filter bags in vacuums also lose their efficiency and their suction as they start to fill up,” Dr. McGrath adds. “For this reason and just for convenience, most patients use the canister vacuums that are bagless.”