But in a statement released Tuesday, the WHO warned that the variant “has a constellation of mutations that indicate potential properties of immune escape.” This means that vaccines or antibody treatments may not work as well against the mu strain as they do against the original version of the coronavirus.
In its weekly pandemic bulletin, the WHO added that preliminary data showed reduced effectiveness of vaccines against mu similar to that seen for the beta variant, which was discovered in South Africa and is considered to be more contagious than the original coronavirus.
There's nothing to prevent people from being infected with multiple strains simultaneously. You can assume all the variants will eventually blend by recombination into even worse variants.