A new study examining blood donations across ten states reveals that antibodies linked to alpha-gal syndrome—an allergy to red meat triggered by lone star tick bites—appear far more frequently than previously estimated. In some regions, up to 30 percent of people carry the antibody, whilst the CDC had estimated only 0.14 percent of the population actually develops the allergic condition, suggesting a much larger population at potential risk.

Alpha-gal syndrome occurs when tick bites introduce a molecule called alpha-gal into the bloodstream, prompting the immune system to produce specific antibodies. However, researchers remain puzzled by the gap between antibody presence and actual disease: many people with the antibodies experience no allergic symptoms, whilst those who do suffer reactions that appear two to six hours after eating, making it difficult to identify meat as the trigger. The condition can cause reactions ranging from hives and gastrointestinal distress to severe anaphylaxis.