Here’s what is known about the Delta variant of coronavirus

he Delta variant of the coronavirus is worrying officials around the world. Four major Australian cities went into a four-day “circuit-breaker” lockdown this week to try and stop it from spreading. Australia’s Prime Minister, Scott Morrison, announced looser vaccination policies to try to get more people immunized before the variant could spread. Ireland delayed plans to resume indoor service in bars and restaurants and US officials urged Americans to get vaccinated to stop its spread.

The World Health Organization says the Delta variant, also known as B.1.617.2, has spread to at least 85 countries since it was first identified in India last fall.