There are fears current vaccines may not offer sufficient protection against the newest Covid-19 variant.
The World Health Organisation has identified the "Mu" strain as a variant of interest.
However, the WHO has not yet said it is a variant of concern.
Kingston Mills, the professor of experimental immunology at Trinity College, says it's not clear if vaccines will protect against Mu.
"The worrying aspect of the new variant is that it has mutations similar to what was found in the South African variant.
"The South African variant is more difficult for the vaccines to protect against than the Delta variant.
"If the new variant gets hold in Europe, it will cause a significant further problem for the vaccine in terms of immunity."