Explainer-Delta dominates the world, but scientists watch for worrisome offspring

Pedestrians walk along a shopping street after the Austrian government placed roughly two million people who are not fully vaccinated against the coronavirus disease (COVID-19) on lockdown, in Vienna, Austria, November 15, 2021. REUTERS/Lisi Niesner

CHICAGO (Reuters) - The Delta variant of the SARS-CoV-2 virus now accounts for nearly all of the coronavirus infections globally, fueled by unchecked spread of the novel coronavirus in many parts of the world. So far, vaccines are still able to defend against serious disease and death from Delta, but scientists remain on alert.

Here is what we know: