Contact Tracing for Covid-19 — A Digital Inoculation against Future Pandemics

Outbreaks of coronavirus disease 2019 (Covid-19) emerged in the United States and in European countries in February 2020. Urgent action was called for, since experts estimated that 30 to 70% of people in these Western countries could become infected — a frightening projection at a time when the Covid-19 mortality rate was estimated to be substantially higher than we now know it to be. In March 2020, Michael Ryan, executive director of the Health Emergencies Program of the World Health Organization (WHO), implored countries to act, noting that when it comes to epidemic response, “speed trumps perfection” but “the greatest error is not to move.” At the time, the only tools for containing Covid-19 were social distancing, testing, case isolation, and contact tracing.