They claim a booster dose of vaccine may therefore be needed to sustain protection among teenagers.
In 1999–2000 the Government ran a mass meningitis C immunisation campaign to vaccinate everyone aged one to 18. Since then the vaccine has been part of the routine infant immunisation programme.
Researchers, led by Dr Matthew Snape, from the department of paediatrics at Oxford University, observed whether children vaccinated as part of the national campaign were still sufficiently protected when they reached adolescence.
They studied the antibody levels in blood samples from 999 adolescents aged 11-20 years who were immunised as part of the original vaccination campaign. They found children aged 10 years or more when vaccinated, maintained protective levels of antibodies for longer.
But over 20%, ‘a significant minority’, of those aged 11–13 years had inadequate protection against meningitis C, the authors said in the BMJ online, and a booster dose of vaccine ‘may be needed to sustain protection against meningitis C amongst teenagers’.