With cases accelerating in many parts of the world due to a post-holiday bump and pushed by more transmissible virus variants in some locations, the world 2 days ago saw its deadliest day of the COVID-19 pandemic so far.In other developments, China announced dates for an international joint mission to arrive to begin work on investigating the animal source of SARS-CoV-2 and Japan announced the identification of a variant in people who traveled from Brazil.WHO joint mission cleared for China arrivalChinese officials today said a joint mission led by the World Health Organization (WHO) will arrive in China on Jan 14, according to Reuters.