The US-based institute expects deaths to peak at the beginning of September then slowly decline afterward, it said in a report published Friday. The IHME’s forecasts distinguish between officially reported Covid-19 deaths and excess deaths attributed to the illness including unreported fatalities.

There have been almost 4.3 million deaths from Covid-19 globally since the start of the pandemic, according to the World Health Organization.

The delta variant is associated with viral loads that are more than 1,200 times higher in newly infected individuals compared with the original coronavirus strain, which means that delta can spread as easily as chickenpox.

Studies from the UK have also shown that delta, which was discovered in India in October, is more resistant to vaccines than the alpha variant that emerged in England in late 2020.