England's Covid-19 mobile phone app will be tweaked so that fewer contacts of asymptomatic people who test positive for the disease will need to self-isolate, Britain's health ministry said on Monday.
Business leaders have raised concerns about the numbers of staff who are having to self-isolate after being "pinged" by the app when they come into contact with someone who then tests positive for Covid-19.
Under the change, if someone tests positive but is asymptomatic, the app will look for their close contacts in the two days prior to the positive test, rather than five days.
The Department of Health and Social Care said that the change would reduce the number of notifications sent by the app, but would not reduce the app's sensitivity, and it would still catch the same number of high-risk contacts.
"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," Health Minister Sajid Javid said.
"This update to the app will help ensure that we are striking the right balance."
Prime Minister Boris Johnson has lifted nearly all coronavirus restrictions in England, saying that vaccines have largely broken the link between coronavirus cases and death, even though the virus remains prevalent.
Some scientists object to the popular phrase "pingdemic" for the disruption to businesses from the self-isolation advice from the app. They say it trivialises the public health benefits of self-isolation when many other measures have been scrapped.
The government has urged people to keep using the app, which is not compulsory.
It said that contacts who were previously being notified to self-isolate in the old system were unlikely to have been exposed to the positive person at the peak of their infectiousness.
Further changes to the self-isolation rules will come in on August 16, when people who are fully vaccinated and come into contact with a positive case won't have to self-isolate unless they test positive themselves.