New ‘How We Feel’ app aims to improve COVID-19 response

How We Feel app

April 3, 2020—A new app called “How We Feel” developed by an interdisciplinary, multi-institutional team of researchers, including Xihong Lin, Jukka-Pekka Onnela, Christine Tedijanto, and Yonatan Grad of Harvard T.H. Chan School of Public Health, could help researchers and public health officials pinpoint COVID-19 hotspots, predict areas that could soon see spikes in COVID-19 cases, understand pertinent risk factors and demographic information, and allow health agencies to better respond to the pandemic.

The “How We Feel” app allows individuals in the U.S. to quickly self-report age, gender, zip code, symptoms, health conditions, and testing results. It does not ask users for a name, phone number or email address, and it leverages “differential privacy” techniques led by Gary King, Weatherhead University Professor at Harvard University, to make data available to researchers while protecting participants’ individual identities. King, who is also the Director for the Institute for Quantitative Social Science at Harvard University, is a member of the team that developed How We Feel.

The app prompts users to share how they’re feeling. If users feel healthy, they report that; if users report that they’re feeling unwell, they will be asked to share their symptoms and health conditions. A daily check-in can be completed in as little as 30 seconds.

“Each health check-in may feel like a small act, but together they’ll make a huge difference for researchers like myself who are trying to understand this outbreak and develop intervention measures to control it. The data gives us a bird’s eye view of COVID-19 that helps us predict regions on the brink of an outbreak,” Lin, professor of biostatistics, said in a press statement announcing the launch of How We Feel. “Our analysis could uncover epidemiological characteristics of the outbreak and how the disease spreads through communities, identify outbreak hotspots, study the time course of symptoms as the disease spreads, estimate region-specific testing needs and strategies for setting up testing prioritization and new testing sites, and evaluate whether interventions such as social distancing have effects on reducing transmission.”

The app is the first product to be developed by the The How We Feel Project, a nonprofit health research consortium whose mission is to make the world healthier by connecting citizens with the global health community, public health and biomedical researchers.

In addition to Harvard Chan researchers and King, several other scientists at Harvard, MIT and the Broad Institute of MIT and Harvard are on the team. They include Feng Zhang, best known for pioneering CRISPR, who is a core institute member at the Broad Institute and an investigator at the Howard Hughes Medical Institute and the McGovern Institute for Brain Research at MIT, and William Allen, a junior fellow in the Harvard Society of Fellows.

External collaborators include Ben Silbermann, co-founder and CEO of Pinterest, and Eran Segal of the Weizmann Institute of Science, who is leading a similar effort in Israel. A volunteer team of current and former Pinterest employees also contributed to the development of How We Feel, as well as researchers from the University of Pennsylvania, Stanford University, and the University of Maryland School of Medicine.

The app is available from the Apple Store and Google Play and the researchers are encouraging broad participation. For more information visit:

Learn more about Xihong Lin’s research on COVID-19.

Chris Sweeney