Vietnam population is around 95 millions, with less confirmed cases than Singapore, despite sharing border with China. Vietnam also acted immediately since first two patients (2 Chinese tourists parent and child), rigorous contact tracing and testing, price control of masks, food and other necessities.
Level of testing / surveillance is not clear.
See https://www.worldometers.info/coronavirus/covid-19-testing/ They have run about 2400 test which is 24 per million in population (on a par with US which is wretched). Italy is 1,000 per million, Hong Kong is 2,000 per million, South Korea is 4,000 per million. Vietnam may be going a good job but they are not testing enough by a factor of 10 to 100 to be sure.
Vietnam is still in containment phase, so tests per million capita is not what I would look at. Rather, about 2400 tests against about 40 confirmed cases is a factor of 60 tests per confirmed cases (this should cover F1, F2). Italy on the other hand is about 60000 tests against 12000 confirmed cases, a factor of only 5. Hong Kong's number is impressive, 120. South Korea's 30.
You make a reasonable argument. In 2003-6 I helped out Viet Cervical cancer project on screening models for Pap smears to detect cervical cancer. Vietnamese incidence was high. Vietnamese public health organization was well organized and effective. Some lessons learned were published in Systems Analysis of Real-World Obstacles to Successful Cervical Cancer Prevention in Developing Countries
