Can the measles vaccine strain revert to a wild-type configuration containing the PEA motif?

The current scientific understanding suggests that vaccine strains of the measles virus are highly stable and do not revert to the wild-type configuration that includes the PEA motif. However, as a precautionary measure, it's essential to maintain high vaccination coverage to prevent the spread of wild-type measles virus, which is the only proven cause of SSPE. The recommended vaccination regimen includes two doses of the measles, mumps, and rubella (MMR) vaccine, administered at ages 12-15 months and 4-6 years. There are no specific medications or interventions recommended for preventing the hypothetical reversion of a vaccine strain to a wild-type configuration. Instead, the focus should be on ensuring widespread vaccination to eliminate the circulation of wild-type measles virus, thereby preventing SSPE. In cases where SSPE is suspected or diagnosed, treatment is primarily supportive, aiming to manage symptoms and slow disease progression, as there is no cure for SSPE.