Abstract
Measles virus is the pathogen that causes measles and is highly infectious. Measles virus
uses two molecules as viral receptors: signaling lymphocytic activation molecule, expressed on
immune cells, and nectin-4, expressed on epithelial cells. Usage of these receptors is strongly
associated with the pathogenesis of measles. Although it remains a leading cause of childhood
mortality worldwide, measles elimination is being promoted by the availability of a highly effective
live attenuated vaccines. Due to the elimination of measles in many countries, the circulating
measles genotypes have been reduced to two, B3 and D8, in recent years. Therefore, in addition to
genotyping using the conventional 450-nucleotide N gene region, new methods such as wholegenome
sequencing and analysis of the M-F non-coding region are being tested for case association
and outbreak tracking. Although measles virus is a single serotype, there are genomic differences
among genotypes, including variations in B-cell and T-cell epitopes. However, current live
attenuated vaccines remain sufficiently effective against all genotypes. On the other hand, the
maintenance of protective immunity in vaccinees may become increasingly important, since
vaccine-induced immunity tends to wane over time unlike the more durable immunity following
natural infection.
