Chinese lab crafts mutant COVID strain with 100% kill rate in ‘humanized’ mice: ‘Surprisingly’ rapid death By . Katherine Donlevy. Published Jan. 16, 2024. Updated Jan. 17, 2024, 7:26 a.m. ET.

STATEN ISLAND, N.Y. — Chinese scientists say an experimental mutant coronavirus (COVID-19) strain has been found to be 100% lethal to “humanized” mice, according to a recent report.