Yes, Vietnam is once again temporarily closed. Countries close and open up all the time. It may open again in the future, but not the foreseeable future, so you'll have better luck looking at other countries. The US was concerned about some corruption, so rather than have the US poking around, Vietnam just cut off adoptions to the US. I'd rather they look into the corruption and fix it, but this was their choice, sadly, to stop the adoptions instead.