Over 300 children have avoided serious illness since the introduction of the pneumococcal vaccine in England 12 months ago, estimates show.
Vaccination saves lives
The jab, given to infants at two and four months with a booster dose at 13 months of age, protects against pneumonia and meningitis.
Experts are calling for more children to be vaccinated, as one in six remain unvaccinated.
Health Protection Agency data show that 86% of children have received the jab.
The government target is 95% uptake.
Director of Immunisation Professor David Salisbury said: "That about 300 young children have already been saved the trauma of suffering from a major illness like meningitis shows the importance of vaccinating children against serious illness.
"It is so important for a child to get all their vaccinations and this success story should serve as a reminder to check that your child's vaccines are up to date."
He said parents should not be put off immunising their children.
"We do not see serious side effects caused by this vaccine."
Sue Davie, chief executive at The Meningitis Trust, said: "Pneumococcal meningitis is a devastating disease and vaccination is the only way to prevent it. That means it is important for parents to immunise their children."
Younger children, particularly those under one year of age, are particularly vulnerable to pneumococcal infection.
Of those young children who survive pneumococcal meningitis, up to half are left with permanent disability, including deafness, intellectual impairment, speech and language problems, paralysis, cerebral palsy, epilepsy and blindness.