A new coronavirus variant from South Africa has been found in the United States for the first time, the Associated Press reports.

Two cases were identified in South Carolina, and state health officials believe it is almost certain that there are more people with the mutated strain who have not yet been confirmed. Both adults who tested positive live in different regions in South Carolina, and do not know one another. They also haven't traveled recently.

Last month, the South African government announced the discovery of the virus variant, which appears to operate much like the UK strain. Both seem to be more easily transmissible, and carry a heavier viral load, but it hasn't been proven if these two are deadlier. The strain coming out of Brazil has many scientists particularly concerned, given how quickly infections were being reported, compared to its UK and South Africa counterparts. 

All three variants have made their way to the United States. The CDC forecasts the UK strain will become the dominant strain in the U.S. by March. With the U.S. seeing a glimmer of light at the end of the tunnel with the early stages of distribution of the vaccine, speculation has rightfully arisen about the vaccine's ability to combat these new mutations. 

Moderna announced this week that even though the vaccine is "expected to be protective" against the South Africa variant, plans are already in place to begin development on booster shots to address the potential threat of this strain. Florian Krammer, vaccine researcher at the Icahn School of Medicine at Mount Sinai, notes that the vaccine is meant to trigger very high levels of antibodies, which could help compensate for a decline in potency in wake of these new mutations. 

For Moderna, these booster shots will either come in the form of a third dose, or tweaking the vaccine to focus on the mutations seen in the South Africa strain.