Measles Virus Genotype Sequencing Status
The provided evidence does not directly address whether all 24 measles virus genotypes have been fully sequenced, but the available molecular surveillance data suggests extensive sequencing has occurred across multiple genotypes, though likely not complete sequencing of all 24 genotypes.
Current State of Measles Genotype Sequencing
The molecular surveillance infrastructure has generated substantial sequence data, with over 50,000 sequence submissions to the Measles Nucleotide Surveillance (MeaNS) database, though this primarily represents the standardized 450-nucleotide region rather than complete genome sequences for all genotypes. 1
Extent of Sequence Data Available
The WHO Global Genotype Database contains over 7,000 genotype reports, and the MeaNS database contains over 4,000 entries as of 2011, with this number growing to over 50,000 submissions by 2024. 2, 1
The standard approach to measles genotyping is based on sequencing 450 nucleotides at the end of the nucleoprotein coding region (N450), not full genome sequencing. 1
Whole genome sequencing is being tested as a newer method for case association and outbreak tracking, alongside analysis of the M-F non-coding region, suggesting complete genomes are not yet standard for all genotypes. 3
Reduction in Circulating Genotypes
Due to measles elimination efforts in many countries, the number of actively circulating measles genotypes has been reduced to primarily two genotypes (B3 and D8) in recent years. 3
This reduction in circulating genotypes has created challenges for molecular surveillance, prompting the development of new tools such as named strains and distinct sequence identifiers to analyze diversity within currently circulating genotypes. 1
Genomic Diversity Across Genotypes
Although measles virus is serologically monotypic, all 24 genotypes have been identified and show genomic differences, including variations in B-cell and T-cell epitopes. 4, 3
The Global Measles and Rubella Laboratory Network systematically monitors measles virus circulation at the sub-genotypic level, determining not only genotype but also genetic lineage and genetic variant. 5