It's generally seen as having as effective response against the pandemic. They closed borders early and have employed an effective testing and tracing strategy. Their data appears to be transparent and is corroborated by neighboring countries.
I just read this, posting the reference in another reply, seems to be a good enough summary:
"One of the reasons Vietnam was able to act so quickly and keep the case count so low is that the country experienced a severe acute respiratory syndrome (SARS) epidemic in 2003 and human cases of avian influenza between 2004 and 2010. As a result, Vietnam had both the experience and infrastructure to take appropriate action. Vietnam makes many key containment decisions in a matter of days, which may take weeks for governments in other countries to make. Although Vietnam is a highly centralized country, a number of key decisions were made at the local level, which also contributed to the swift response."
It's generally seen as having as effective response against the pandemic. They closed borders early and have employed an effective testing and tracing strategy. Their data appears to be transparent and is corroborated by neighboring countries.