Late last July, the Hanoi University of Science and Technology, the National Hospital of Tropical Diseases, and Vietnam Airlines installed a special positive pressure cabin to limit the spread of infection on a flight bringing home Vietnamese citizens suffering from COVID-19 in Equatorial Guinea. How best to limit the spread of the virus has kept many scientists awake at night. The portable air filters were devised in three months and meet technical parameters certified by the Ministry of Health. A similar imported product costs nearly a thousand dollars, but this Vietnamese product is only around a hundred dollars. Scientists hope to receive more support from companies and investors to develop the filter for the commercial market./.