This week, the NHS Covid-19 app has been updated to be less sensitive, meaning that fewer people will be required to self-isolate after coming in contact with someone who has tested positive for coronavirus. The app will now only ‘ping’ close contacts from two days prior to the reported positive test instead of five.

This significant change comes from widespread criticism of the app’s sensitivity after 700,000 ‘pings’ were sent out late July in England and Wales, which had a catastrophic impact on some industries and services, including the suspension of bin collections due and empty supermarket shelves due to staff shortages from isolation.

Sajid Javid, the Secretary of State for Health and Social Care, mentioned that “we want to reduce the disruption that self-isolation can cause for people and businesses, while ensuring, we’re protecting those most at risk from this virus”. He also said that “this update to the app will help ensure that we are striking the right balance”. However, with millions of people still deactivating or uninstalling the app due to fears of unnecessary self-isolation, the ability of the NHS Covid-19 app to break chains of transmission is hindered.

This is concerning when considering the new Delta variant, which the CDC warns as one of the most infectious diseases ever! A report published by China’s Centers for Disease Control and Prevention noted the viral loads in the Delta variant infections were 1,260 times higher than its original counterpart.

The NHS Covid-19 app is one of the world’s most downloaded medical software products according to Zühlke, the creators of the app. Researchers at the Alan Turing Institute and Oxford University estimate that for every 1% increase in users, Covid cases can be reduced up to 2.3%. Yet, it has been difficult to gauge the effectiveness of Bluetooth-based proximity detection because of privacy protections built into phone systems. As a result, it is largely unknown how many people have complied with isolation orders.

Labour’s shadow health and social care minister Liz Kendall criticised the tweaks to the app as the government abandoning its attempts to keep infection rates low. With less people being told to self-isolate, the higher the chance someone carrying the disease, perhaps unknowingly, can infect others.

Perhaps the technology is not the problem. Many complaints about the app revolve around wider health policy. Jenny Wanger from Linux Foundation Public Health argues that the science behind the app is not the challenge, but rather the behaviour: ‘[t]he hardest parts of the system are the parts where you need to convince people to do something.’ The receptiveness of public health technology is closely connected to how it is marketed, how it is discussed in the media, and more.

In recent weeks Britain has been adjusting to the ‘new normal’ - for the contact tracing app to remain effective in saving lives and keeping infection rates low, the government must ensure that people continue using it.

By: Nicole Woo

To Delete Or Not To Delete - Revising The Need For The NHS Covid-19 App