The research also identified rare genetic variants that may help explain why some people developed more severe COVID-19 than others. Understanding the evolutionary history of immune genes can provide insights into why people respond differently to infectious diseases today.” Rare gene variants linked to severe COVID-19The researchers then turned to a different question: Could some of these immune genes also help explain severe COVID-19? Because organ transplant recipients are already known to face a higher risk of severe COVID-19, the finding suggests a TLR2 variant could be one factor influencing that increased risk. “By tracing that evolutionary history, we can better understand why people respond differently to infectious diseases today and identify biological pathways that may inform new strategies for disease prevention and treatment.”