The World Health Organization says the spread of the coronavirus across more than 100 countries now qualifies as a global pandemic. Six continents have reported cases of the virus, which has infected more than 120,000 people and killed more than 4,300. While the designation is largely symbolic it is hoped the public will be more aware of the potential dangers of the virus. The W.H.O. had not declared a pandemic since 2009, when it gave that designation to a new strain of H1N1 influenza.