An official from the Civil Aviation Authority of Vietnam (CAAV) has said that Vietnam will change the routes of all flights with paths through Ukraine.

Aftermath of the Malaysian Airlines crash in Ukraine
Lai Xuan Thanh, Director of the CAAV, said on July 18 that the agency and the national flagship carrier Vietnam Airlines had reached an agreement to change the routes of all flight going through those areas that see violence.
Currently, Vietnam Airlines is the only domestic airline in Vietnam with flights thorough these areas.
Concerning the most recent Malaysian Airlines plane crash, Thanh said, “The incident has shocked the world. It’s unbelievable. If it turns out to be true that a civil plane was shot down, it would be really a terrible catastrophe for the entire aviation industry.”