You bought the best HEPA vacuum money could buy -- and you're still sneezing.
Your allergy symptoms may be due to dust mites, not pollen. Vacuuming actually stirs up dust mites. Although a HEPA vacuum can be your best friend if you're allergic to pollen and ragweed, if dust mites are the "achoo trigger," a HEPA-filtered machine might not be any better than a standard one. Time to get someone else to take over this chore, while you take a walk.
Although a HEPA vacuum greatly reduces the total number of particulates in the air, like any vacuum, it sends dust mites swirling. To keep the microscopic-sized critters from irritating your nose while getting the crumbs out of the carpet, take a couple of self-protective measures. First, be sure that the person who vacuums also empties the dust compartment outside -- even more dust mites are stirred up during this step. Second, consider selling your fancy HEPA vacuum to a neighbor or on eBay, then replace it with one that steam cleans and picks up debris. Researchers have found that steamy carpet cleaning reduces dust mites to such insignificant levels that allergy symptoms cease and desist.