Extending the vaccination programme is expected to lead to a similar dramatic decrease in cases of group C meningitis and septicaemia in 20 to 24 year olds.
Pathologist Dr Roger Williams told the inquest that the post mortem examination showed overwhelming infection and septicaemia which came from the injections, although the surgeon had used sterile needles.
The trust said the Dr Foster independent investigation found that of 150 patient cases - not all fatal - coded as septicaemia, 76 were found not to meet national coding standards.