Britain's health secretary said it could make vaccines at least 40 per cent less effective, and as a result he said they had banned flights from South Africa and five other regional countries.
Deakin University epidemiologist Professor Catherine Bennett said the B.1.1.529 variant spreading rapidly in South Africa was a standout for the sheer number of mutations it contains but also for where many of these were located.
"Usually a new variant only has a handful of important mutations," she told news.com.au.
While there may be other minor changes, the major ones generally change things like the virus' transmissibility for example.
In comparison to the handful of major mutations in other variants, the latest version had more than 50 mutations, which Bennett said was "unusual".
"More than 30 are in the spike region alone," she said.
Five quick tweets on the new variant B.1.1.529
Caveat first: data here is *very* preliminary, so everything could change. Nonetheless, better safe than sorry.
1) Based on the data we have, this variant is out-competing others *far* faster than Beta and even Delta did 🚩🚩 pic.twitter.com/R2Ac4e4N6s
Mutations in the spike region are particularly significant because this is where the virus attaches to human cells. It's also that part of the virus vaccines focus on.
The World Health Organisation said this variant had at least 10 mutations linked to the receptor-binding domain on the protein spike. This compared to two for Delta or three for Beta.
"The concern is that when you have so many mutations, it can have an impact on how the virus behaves," WHO technical lead on Covid-19, Maria Van Kerkhove, said at a virtual press briefing.
"It will take a few weeks for us to understand what impact this variant has on any potential vaccines."
"The good news for New Zealand - or the reassuring news for us - is that whatever this variant does, New Zealand is well placed to manage the threat because we know that we can keep this virus out if we have to, and most countries obviously are not in that fortunate position," Baker told RNZ