Viruses mutate all the time, so it’s no surprise that the coronavirus which emerged in China at the end of 2019 has undergone significant mutations as the virus replicates and spreads.

But a new strain that has emerged in South Africa is causing concern. Like a variant discovered in the U.K. in recent months, the one that in South Africa is proving to be far more transmissible.

While the two strains spread more easily, scientists do not believe they are deadlier. But being more transmissible means more people can get infected, and this could mean more serious infections and more fatalities.

Questions are now being raised over whether the coronavirus vaccines developed at breakneck speed in the last year, the Western frontrunners being those developed by Pfizer-BioNTech, Moderna and the University of Oxford/AstraZeneca will be effective against significant mutations of the virus, such as the one identified in South Africa.

While scientists believe the U.K. variant is not likely to affect the efficacy of the vaccines currently being rolled out in the West, there is more uncertainty regarding the other strain.

Experts are keen to point out that there’s still a lot we don’t know about the new strains, although they are being investigated, and they are urging people not to panic. 

What do we know about the variant?

On Dec. 18, South Africa announced the detection of the mutation that was rapidly spreading in three provinces, becoming the dominant strain in Eastern Cape, Western Cape, and KwaZulu-Natal provinces.

South Africa named the variant “501Y.V2” because of the N501Y mutation they found in the spike protein that the virus uses to gain entry into cells within the body. This mutation, among others, was also found in the new strain that the U.K. identified in December (but estimated to have been in circulation since September) with both regarded as increasing the transmissibility of the virus, making it spread more efficiently.

With authorities in the U.K. and South Africa alerting the World Health Organization to the new mutations in December, the WHO noted that while both variants found in the U.K. and South Africa shared the N501Y mutation, they are different.

The variant in South Africa carries two other mutations in the spike protein (E484K and K417N, among others) which are not present in the U.K. strain, named “VOC-202012/01,” with VOC standing for “Variant of Concern.” Experts said the mutations could affect how vaccines against Covid work.

How worried should we be?

Some experts are worried about the South Africa variant, now more widely known as “501.V2.” So far, it has only been found in a handful of cases, WHO noted Tuesday, albeit in an increasing number of countries including the U.K., France, Switzerland, Japan, Austria and Zambia.

Multiple countries have banned flights from South Africa and the U.K. as a result of the new strains in a bid to stop their spread.

Earlier this week, U.K. Health Secretary Matt Hancock said the variant found in South Africa was especially concerning. “I’m incredibly worried about the South African variant, and that’s why we took the action that we did to restrict all flights from South Africa,” he told the BBC’s “Today” program Monday.

“This is a very, very significant problem, ... and it’s even more of a problem than the U.K. new variant,” he said without explanation.

On Tuesday, former U.S. FDA chief Dr. Scott Gottlieb warned that vaccinating Americans against Covid is more critical than ever, especially as the variant in South Africa appears to inhibit antibody drugs, and is spreading elsewhere.  

“The South Africa variant is very concerning right now because it does appear that it may obviate some of our medical countermeasures, particularly the antibody drugs,” Gottlieb told CNBC’s “The News with Shepard Smith” on Tuesday.