BEIJING/MELBOURNE : Papua New Guinea has denied entry to Chinese nationals who participated in a COVID-19 vaccine trial, the Australian newspaper said on Friday, as the Pacific nation battles a worsening outbreak of the respiratory disease.The workers had been due to fly from the northern city of Tianjin to the Ramu NiCo plant in northern Papua New Guinea run by state-run Metallurgical Corporation of China Ltd (MCC) .The Australian said David Manning, Papua New Guinea's head of disaster management, denied access for the workers after being told of the vaccinations, however, and sent a strongly worded letter to China's ambassador, Xue Bing."The government of PNG demands and deserves to fully understand (the) vaccine development and.