Campaigners have won a victory after revealing how an error within the EMIS prescribing system led to teenagers being unprotected against meningitis – in spite of visiting practices.

The system had an alert to identify doctors that an eligible patient had not received the MenACWY vaccine – but this was switched off to avoid “alert overload.”

Instead practices were issued with instructions for switching the alert on locally – but many reported being unable to do this.

The problem was uncovered following the death of 21-year-old Tim Mason, from Tunbridge Wells, Kent, in March last year from meningococcal sepsis.

His family worked with charity the Meningitis Research to investigate his death and discovered that he had visited his GP several times since the introduction of the vaccine – but had never been asked to have it.

This was because the issue was never flagged up by EMIS – because its alert was switched off for the victim.

Now health minister Seema Kennedy has told the charity that the alert has been switched on because of its findings. The change was made last month.

Ms Kennedy told the charity: “The protocol was not activated by default, but instructions were sent out for local activation. In response to your letter, it has been agreed that this alert will be enabled for all EMIS users in England.”

Charity chief executive Vinny Smith said: “It seems absurd to us that an emergency vaccination programme to protect young people against a lethal disease had systems in place that were switched off.

“Practices needed to activate the MenACWY alert protocol in order to use it but this would rely on them knowing how to do so. Practices told us they did not know how to activate the alert and we know deaths from MenW disease have occurred in young people who should have been offered the vaccine.

“We admire the courage of the Mason family as they have raised awareness and triggered change within the NHS that will help avoid further deaths from this preventable, treatable disease.”