In 2017, the Journal of Virology published a paper called "Antigenic Drift Defines a New D4 Subgenotype of Measles Virus". This study described a mutation within the Measles virus D4 genotype, named D4.2. Subgenotype D4.2 was isolated in countries with higher vaccination coverage, like France and Great Britain. Page 10 of the study mentions this "...might suggest that an intermediary level of vaccine coverage provides an environment more prone to adaptive mutations."

​

 The Measles virus D4.2 subgenotype showed to be resistant to antibodies produced from vaccine induced immunity. This Measles subgenotype is resistant to vaccine antibodies at 3 of the 6 sites due to its lack of epitopes (the epitope is where the antibody would attach itself). - "We observed that subgenotype D4.2 viruses are resistant to monoclonal antibodies targeting three of the six known MeV-H protein antigenic sites (BH129, BH047, BH059, BH125, and BH097)." Page 9. The resistance being due to evolution making the sites inaccessible "As a consequence, S247 would not be accessible, explaining the lack of an effect on both virus neutralization and antibody binding for the MeV-H S247P mutant" Page 9.

​

 Interestingly enough the highest amount of cases in the US since measles was declared "eradicated" in 2000 was caused by this mutant subgenotype.

"In 2011, these subgenotype D4.2 viruses were imported from France to the United States in 2011, causing the highest number of measles cases since it was declared eliminated." Page 10.