The NHS Covid app could be made less sensitive so fewer people are forced to quarantine, according to reports.
The app detects the distance between users and the length of time spent in close proximity - currently 2m or less and more than 15 minutes.
Transport Secretary Grant Shapps has said the “sensitivity” of the NHS Covid app is being kept under constant review.
He said it was important that it remained a “useful tool” in the fight against the disease amid concerns about the increasing numbers of people being “pinged” as restrictions are eased.
It comes as Pfizer is expected to seek US approval for a booster vaccine. The drugmaker's top scientist said on Thursday, a booster would give protection based on evidence of greater risk of re-infection six months after inoculation and the spread of the highly contagious Delta variant.
Pfizer's own data from the United States showed an erosion of the vaccine's efficacy after six months against the variants circulating there in the spring.
