A recent study has shed light on the long-term protection provided by measles vaccinations, particularly in light of a rise in cases among children in the UK. The findings indicate that over 95% of individuals who have received two doses of the measles, mumps, and rubella (MMR) vaccine, introduced in 1988, are protected for life. However, despite the vaccine’s high effectiveness, there has been an increase in measles infections among those who are double-vaccinated.
According to data from the UK Health Security Agency (UKSHA), most measles cases in England occur in unvaccinated children and young people, though there has been a notable rise in infections among the double-vaccinated population. Researchers from The London School of Hygiene & Tropical Medicine (LSHTM) conducted a modelling study that suggests the MMR vaccine’s effectiveness may gradually decrease by 0.04% per year after the second dose, potentially contributing to breakthrough cases in vaccinated individuals.
Experts emphasize that the slight waning of MMR vaccine immunity is primarily due to lower vaccination coverage, falling below the World Health Organisation’s (WHO) 95% target. Only 85% of under-fives in England have received two doses of the MMR vaccine, highlighting the importance of achieving higher vaccination rates to prevent measles transmission and outbreaks.
Dr. Alexis Robert, from LSHTM, highlighted that outbreaks of measles in recent years correlate with declines in vaccine coverage, leading to a rise in cases among vaccinated individuals. Despite the slow waning of vaccine immunity identified in the study, experts maintain that the MMR vaccine remains safe and highly effective in preventing measles outbreaks.
Studies also revealed a three-fold increase in measles cases among adults who received two MMR vaccine doses in England between 2011 and 2019. Mathematical modelling demonstrated that gradual waning of vaccine immunity aligns with the distribution of measles cases among the double-vaccinated population by age group and over time.
Overall, health officials stress the importance of maintaining high vaccination coverage to protect against measles and other preventable diseases. The World Health Organization underscores the significance of attaining and sustaining a 95% population uptake for two MMR doses to achieve global measles elimination. The MMR vaccine remains the most effective and safest strategy in combating measles, and parents are encouraged to ensure their children are up to date with vaccinations to prevent outbreaks and protect public health.