Japan's total number of confirmed COVID-19 cases topped 500,000 on Friday, as the country braces for a possible fourth wave of infections.The spread of infections has maintained a rapid clip, taking just two months for the number to increase by 100,000 from 400,000 in early February, while vaccines remain widely unavailable in the country, which is now grappling with the emergence of more contagious variants.On Friday, Japan's daily nationwide tally was more than 3,000 cases for the third straight day, with the government adding Tokyo and Kyoto and Okinawa prefectures to the list of being d…READ FULL ARTICLE