ANTONI SLODKOWSKI and SAKURA MURAKAMI JAPAN’S most senior medical adviser said that hosting the Olympics during a pandemic was "not normal" while the media reported thousands of volunteers quitting in advance. Most Japanese oppose holding the Olympics - due to start on July 23 after postponement from last year - while doctors fear the event would strain a healthcare system seeing record numbers in critical condition and struggling to vaccinate the nation. In one of the strongest warnings yet, government medical adviser Shigeru Omi said organisers should explain to the public why they are going ahead. "It's not normal to…