“People don’t answer their phones, people don’t want to get a contact from an unknown number.”
Local contact tracing efforts have been stepped up, in part due to the public’s reluctance to pick up the phone, she added.
Working with local councils and directors of public health, local systems can “find some of these individuals that the national system cannot,” she said.
A number of experts have urged ministers to use the forthcoming lockdown to ensure that the Test and Trace system is up to scratch.
On Saturday, Dr David Strain, senior clinical lecturer at the University of Exeter, said: “In order to minimise the impact of the lockdown on the mental and physical health of the nation as well as the economy, this needs to be accompanied by a clear exit strategy, including an overhauling of the Test and Trace system to ensure it is fit for purpose.”
On the lockdown, Dr Hopkins, who is also deputy director of Public Health England’s National Infection Service, said there was a “fine balancing act” about when to implement a lockdown.
She told Times Radio Breakfast: “I think that even if we had done a lockdown earlier, it’s likely we would probably need one again later on. So there’s a fine balancing act about when this occurs.