Who is Dr Michiaki Takahashi, Japanese virologist honoured by Google Doodle today?

Google dedicated its Doodle on Thursday to Japanese virologist Dr Michiaki Takahashi, who developed the first vaccine against chickenpox, to mark his 94th birth anniversary. Takahashi, who was born in 1928 in Osaka, began working on the vaccine after his son caught chickenpox. In 1986, Japan rolled out his varicella vaccine and it was soon utilised in over 80 countries.