LONDON (AP) — The World Health Organization is estimating that nearly 15 million people were killed either by the coronavirus or by its impact on overwhelmed health systems in the past two years. That is more than double its official death toll. The U.N. health agency says most of the fatalities were in Southeast Asia, Europe and the Americas. In a report released Thursday, WHO chief Tedros Adhanom Ghebreyesus describes the figure as “sobering.” Accurate numbers on COVID-19 deaths have been problematic throughout the pandemic, as the figures are only a fraction of the devastation wrought by the virus. That is largely due to limited testing and the differences in how countries count COVID-19 deaths.