What the news reports on this either aren't saying, or are burying at the bottom of their articles, is the vaccination stats in Vietnam: a country of 97 million people, they've only vaccinated a million people so far. So about 1.03% of the population.
This variant is not helpful news for the people of Vietnam, and possibly neighbouring countries (Laos, Cambodia, Malaysia, Brunei). I don't think it represents a significant threat here in the UK.
Besides, we know that the vaccines we have are effective against both the UK and Indian variants; if this is a hybrid of the two, there's every likelihood that the vaccines will work against this one too.
What we should be caring about is that the Vietnamese government speeds up its vaccination programme.