The World Health Organization (WHO) today announced that its vaccine advisors have approved emergency listing for China's inactivated two-dose Sinovac COVID-19 vaccine, and yesterday it unveiled a simplified Greek alphabet-based naming system for key SARS-CoV-2 variants.In other developments, the WHO and some of the world's biggest financial organizations today put out a call for $50 billion to help end the pandemic, which comes ahead of a Gavi COVAX donor summit tomorrow and a G7 summit in the United Kingdom the following week.Sinovac listing brings WHO list to 7The WHO's Sinovac vaccine action marks the group's second clearance of a Chinese vaccine and the seventh vaccine to be listed.