Experts have warned that Covid “hasn’t gone away” after an uptick in infections and hospitalisations that is thought to have been caused by new variants of the virus.

A group of Covid mutations has recently emerged and is collectively referred to as FLiRT.

According to the UK Health Security Agency (UKHSA), Covid hospital admissions increased by 24 per cent in the week to Sunday, with a rate of 3.31 per 100,000 people compared with 2.67 per 100,000 in the previous week.

Professor Lawrence Young, a virologist at Warwick University, said the figures should serve as a “wake-up call” to those who think the virus has gone away.

“The virus hasn’t gone away and is certainly not a seasonal infection,” he told the i newspaper. “A combination of new, more infectious virus variants and waning immunity is very likely contributing to these increased levels of infection. The hope is that this will not result in a big wave of infection, but we need to keep a close watch.”