a Interpolated percentage of ragweed sensitised persons in the European population. b Geographic distribution of studies assessing overall sensitisation rates among the general population in Europe. Size of points indicates overall sensitisation rates (%) among the persons tested. c Geographic distribution of studies assessing ragweed sensitisation rates among the sensitised human population in Europe. Size of points indicates ragweed sensitisation rates (%) among the sensitised persons tested. Studies are based on ragweed specific skin prick tests or circulating ragweed specific IgE tests.