The UK’s track and trace system needs to be scaled up to avoid a worse second wave when schools reopen, researchers have warned.

The planned September return to school must be accompanied by a far-reaching test-trace-isolate (TTI) programme, a modelling study published in The Lancet Child And Adolescent Health suggests.

The study simulated various scenarios to look at the potential impact of schools reopening at the same time as parents returning to work and increased socialising within the community.

The researchers, from University College London (UCL) and the London School of Hygiene and Tropical Medicine (LSHTM), found that “with increased levels of testing… and effective contact tracing and isolation, an epidemic rebound might be prevented”.

The test-and-trace system, which could lead to any member of staff or the study body being forced to isolate for two weeks, could raise issues for independent school leaders and managers, with implications for staffing, pay and pupil attendance.

The modelling study found that, in a worst case scenario, a second wave could be over two times the size of the first if there is a “continual gradual relaxation [of] control measures and insufficient test-trace-isolate”.

Dr Jasmina Panovska-Griffiths, who led the study, said: “Our modelling suggests that with a highly-effective test and trace strategy in place across the UK, it is possible for schools to reopen safely in September.

“However, without sufficient coverage of a test-trace-isolate strategy, the UK risks a serious second epidemic peak either in December or February. Therefore, we urge the government to ensure that test-trace-isolate capacity is scaled-up to a sufficient level before schools reopen.”

Professor Chris Bonell, professor of public health sociology at LSHTM said the findings should “not be used to keep schools shut” but should be viewed as a “loud call to action to improve the infection control measures and test and trace system”.