Apr 23, 2020

Algorand's Approach to COVID-19 Tracing

By: Silvio Micali

The COVID-19 pandemic has disrupted the business and personal lives of people all around the world. The severe contagiousness and virulence of this infection has forced governments to make tradeoffs between economic activity and the safety of their citizens. This situation will continue until the transmission and severity of the contagion can be addressed.  

The most effective means for slowing this contagion is the massive deployment of an effective vaccine. Vaccination not only protects the individual; it also protects the entire population. The resulting herd immunity will greatly decrease the available infectious hosts, potentially breaking the chain of transmission. This herd immunity is essential for those who cannot be vaccinated such as the immunocompromised, the newborn, etc. We are hopeful that the timeline of vaccine development can be accelerated, because the entire medical community of the world is focused on this task. However, vaccinating most of the population may take a long time. 

Other tools exist for battling infectious diseases for which vaccines are not yet available. Isolation and contact tracing have been popular complementary methods for centuries (think of the Venetian quarantine in the 1348 black death outbreak). Indeed, identifying transmission chains and breaking them, via isolation or treatment, are very effective ways to control the spread of diseases. 

To be sure, no matter how well designed, a contact tracing app is no substitute for a well-organized medical system where everyone can be tested. However, contract tracing remains important even when all other tools are in place. In fact, since this disease is spread even by asymptomatic individuals, contact tracing is most useful when ubiquitous testing is available.

1.    Which Contact Tracing?

Several methods of automatic contact tracing have been recently suggested that employ the near ubiquitous smartphones to facilitate data collection. These methods could easily yield a detailed graph of social interactions, if one were willing to ignore privacy concerns.