A new Oxford University study found that the duration of an encounter with a person sick with COVID was as important as the distance kept from them.
How likely is it to get COVID-19 after being exposed to someone infected? It’s been a question on many people’s minds during the pandemic, and one that a group of researchers in the UK has finally found an answer to.
Researchers from the Nuffield Department for Medicine at the University of Oxford analysed data from 7 million people in England and Wales who, during the health emergency, were notified by the country’s NHS COVID-19 app that they had been in contact with someone who was infected.
The goal was to find out how many of those alerted actually contracted the SARS-CoV-2 virus.
The NHS COVID-19 app, which was closed down in April 2023, allowed people who had downloaded it to let others know that they had been infected.
At the same time, the app would send users an alert if they had come in the proximity of someone who was infected, (based on non-mandatory reporting to the app). People would then have to either self-isolate or get tested.
The job of Luca Ferretti, the lead researcher of the University of Oxford study that was published in the journal Nature this month, and his colleagues was to understand if the app had worked correctly.
Did it notify people when there was a reasonable risk? The short answer is yes. But the researchers found out much more than that.