Since most of us are unable to room with a pig, we have to come up with a plan. Can we avoid allergies altogether? Can we get rid of allergies we already have? Can we desensitize our immune systems? "We still don't know exactly how to prevent allergies," says Andrew Liu. "We know the immune response is supposed to be a helpful one, that it's not supposed to be the cause of disease. We know that the immune system of someone with allergies needs to be reeducated. But how? It's not always clear." Leung agrees, adding, "If you are exposed to ... microbial products early in life, it may prevent allergies. But later in life, the early exposure may actually make things worse.