Eric Liang Feigl-Ding (born March 28, 1983) is an American public health scientist who is currently an epidemiologist and Chief of COVID Task Force at the New England Complex Systems Institute.

[1] Feigl-Ding is also the Chief Health Economist at Microclinic International,[19] as co-principal investigator of several intervention programs for obesity and diabetes prevention in the US and abroad.

[5][24][25][26] He was one of over 3,000 researchers who participated in the Global Burden of Disease Study, funded by the Bill & Melinda Gates Foundation.

[27][18] On January 25, 2020, Feigl-Ding went viral[4] on Twitter after expressing his worries about the 2019–20 Wuhan coronavirus outbreak virus' basic reproduction number (R0) of up to 3.8.

[28] While Feigl-Ding deleted his earliest tweets,[3] the rapid development of the epidemic, first in China in January, then in Europe in February–March and in the United States in March, together with more studies on the virus, turned his perceptions into that of an early messenger,[3][7] and he was invited as a commentator on the pandemic by news media.

[28] New York Magazine editor David Wallace-Wells's article that convinced Madrigal to change his assessment concluded that "a Feigl-Ding level of alarm, enacted into public-health policy at the right time, could have prevented the entire global pandemic crisis, and kept COVID-19 a regional health story in just one country of the world.

[30] Feigl-Ding's rapid rise to prominence as a TV and media commentator and expert during the COVID-19 pandemic, despite his lack of academic activity in infectious diseases, has led to much criticism and controversy.

[32][30] He received early criticism for offering public warnings on the COVID-19 pandemic as well as praise from David Wallace-Wells,[3] editor-at-large at New York Magazine.

A January 2020 article published by The Atlantic covered the early controversy of Feigl-Ding's social media presence.

[8] On March 26, Alexis Madrigal, its author, re-assessed his piece and stated that "it was right in the particulars and wrong on the big picture.

[37] He received the CUGH's Global Health Project of the Year Prize in 2014,[38] and the American Heart Association's Scott Grundy Excellence Award in 2015.