A new British study suggests people who get COVID-19 from the extra-contagious delta variant are about twice as likely to be hospitalised than those who caught an earlier version of the Coronavirus.

The delta variant spreads much more easily than the alpha variant that previously was widespread in much of the world. But whether it also causes more severe disease is unclear, something hard to tease out - in part because delta took off just as many countries relaxed their pandemic restrictions even as large swaths of the population remained unvaccinated.

Researchers with Public Health England examined more than 40,000 COVID-19 cases that occurred between March and May, when the delta variant began its surge in Britain, to compare hospitalisation rates. The results were similar to preliminary findings from a Scottish study that also suggested delta triggered more hospitalisations.

Importantly, less than 2 per cent of all the cases tracked in the newest study were among the fully vaccinated. The findings were published Friday in The Lancet Infectious Diseases.