Vietnam has blocked two cruise ships from docking amid fears of coronavirus infections on board, according to state media, ship tracking websites and messages posted to social media by passengers.Authorities in Quang Ninh province, home to the Unesco World Heritage Site Ha Long Bay, decided on Tuesday not to allow passengers of the German-owned AIDAvita cruise ship to disembark on Thursday, the state Vietnam News Agency (VNA) reported.“The vessel has docked in the Philippines, Malaysia and…