A study appearing in the journal Science suggests that a significant amount of the transmission of the SARS-CoV-2 virus may be from people who are presymptomatic.
As a consequence, the authors suggest that a mobile app-based contact tracing system would radically reduce the amount of time it takes to identify people who have come into contact with the person who has developed the disease COVID-19.
This could significantly reduce the overall rate of spread of the virus, paving the way for what the authors call “intelligent social distancing,” rather than national lockdown.
The scientific evidence that is informing government policy in the United Kingdom, and other countries around the world, currently recommends a policy of suppressing the SARS-CoV-2 virus rather than mitigating it. By this, the evidence suggests reducing its spread, as far as possible, primarily through significant and extensive social distancing.
The research suggests that this will significantly reduce the number of people who die as a consequence of the virus transmission, as well as reduce the pressure on public health services — particularly critical care units — that have been left underfunded following 12 years of austerity measures since the 2007–2008 financial crisis.
A suppression strategy requires widespread social distancing until scientists can produce an effective vaccine. While this approach has reduced the overall level of mortality, it is also likely to have a range of negative social, economic, and ethical effects.
In the words of the authors of the research currently influencing government policy in the U.K., “The social and economic effects of the measures [that] are needed to achieve this policy goal will be profound.”
Finding ways to minimize the time people have to spend social distancing is, therefore, critical.
The research in the new study helps in this regard by identifying the relative rates of transmission of the virus. The authors use this information to propose a mobile app-based tracing system that could play a significant part in reducing the spread of the virus and enabling people to spend as little time social distancing as possible.
After analyzing data on the different ways the virus has spread in China and Singapore, the researchers estimate that almost half of the transmissions of the virus are by people who have yet to show symptoms of COVID-19.
This means that once these people develop symptoms, rapidly tracing other people they have come in contact with could play a large part in reducing the spread of the virus.
The challenge, however, is that current approaches to contact tracing take a relatively long time, and the longer contact tracing takes, the more time the virus will have to spread to other hosts.
By using a mobile app-based contact tracing method, the authors predict that the authorities could radically reduce the contact tracing time.
As Dr. David Bonsall, senior researcher at Oxford University’s Nuffield Department of Medicine and clinician at Oxford’s John Radcliffe Hospital, and co-lead of the project, explains “The mobile app concept we’ve mathematically modeled is simple and doesn’t need to track your location; it uses a low energy version of Bluetooth to log a memory of all the app users with whom you have come into close proximity over the last few days.
“If you then become infected, these people are alerted instantly and anonymously and advised to go home and self-isolate. If app users decide to share additional data, they could support health services to identify trends and target interventions to reach those most in need.”
The team recognizes that there may be some ethical issues with this approach.
It hopes that by following a series of principles, it will be able to demonstrate that the project is something the public can trust and that they will, therefore, achieve the significant uptake necessary for it to be successful.
These principles include:
- having the project run by a transparent advisory board
- publishing the ethical principles that guide the project and ensuring their transparency
- committing the project to equity of access and treatment
- ensuring the algorithm running the app is transparent
- ensuring the research informs future preparations for viral outbreaks
- managing data carefully
- sharing the knowledge that the project gains with other countries
- ensuring the app requires minimal imposition on users
For Prof. Michael Parker, director of the Wellcome Centre for Ethics & Humanities in the U.K., and one of the paper’s authors, “With transparent and inclusive ethical oversight to ensure genuine public trust, it is possible to both save lives and protect civil liberties.
“The app should be opt-in, provide secure data storage and privacy protection, and be informed by public and user engagement at every stage of implementation. With these guarantees and if widely installed by users across a country or regional bloc, a mobile app could even help to end the epidemic.”
The authors note that even when considering that not all people have access to a smartphone, not all of those who have access will enable the app, and social distancing is imperfect, their research, nonetheless, suggests that an app, in combination with other social distancing measures, could play a major part in reducing the rate of infection.