The U(achoo)nited (achoo) St(achoo)ates (achoo)

Analysis of pediatric data finds that children born outside the U.S. have much lower rates of allergy and asthma even once they move here. However, this advantage disappears after a few years of living here: http://www.sciencenews.org/view/generic/id/350112/description/Allergy_asthma_less_frequent_in_foreign-born_kids_in_US