Meningococcal C conjugate age-dependant long-term loss of effectiveness

After 10 years, vaccine effectiveness decreased by 50% in those vaccinated at <1 year, while those vaccinated with one dose at 12-19 years showed no changes. Vaccine failures occurred early after vaccination and more frequently in those vaccinated at younger ages. Vaccination at ≥12 years seems to be related to a low number of vaccine failures and a higher and endurable protection over time.