The head of the inquiry set up after the Soham murders says there is still a "great deal to be done" in implementing his two main recommendations.
Sir Michael says a national system must be put in place
Sir Michael Bichard reported in June on failures that allowed murderer Ian Huntley to work as a school caretaker.
"Good progress" had been made in implementing most of his 31 proposals.
But the introduction of the national IT intelligence system and the barring system for those working with children were "by no means guaranteed", he said.
Ian Huntley murdered Holly Wells and Jessica Chapman, both 10, in Soham, Cambridgeshire, in 2002. He had worked as a caretaker at Soham Village College.
Sir Michael's inquiry focused on the issue of police forces and related agencies sharing information about suspects.
"We can never guarantee that someone like Huntley will not slip through the net but we can improve significantly the chances of preventing that if all of these recommendations are successfully delivered," he said on Tuesday.
Work done in the last few months had "gone a long way" to ensuring that, he added.
"We are actually on the verge of having, in the UK, a coherent set of protection measures probably unrivalled anywhere in the world.
"But if the national intelligence system and the barring scheme are not in place by 2007 then we will still have fallen seriously short."
He said resources and laws were needed to create the scheme to bar people who should not work with children.
Ian Huntley had been accused of several sex-related crimes
And he said slow progress in the time taken to input details of arrests and summonses on to the Police National Computer (PNC) was "disappointing".
In July, it took forces an average of nine days to enter arrest or summons data, but that was now taking 10 days, he said.
Forces that failed to improve should be "named and shamed", he added.
Sir Michael called on the Home Secretary Charles Clarke to keep all the recommendations "on track".
The home secretary said he accepted all of Sir Michael's further recommendations in principle.
He added: "I am pleased that Sir Michael has recognised that 'significant progress' has been made."
Sir Michael said he was impressed by improved online training for teachers involved in interviewing for jobs and new policies on entering information on the PNC.
Good progress had also been made on reducing the number of registered bodies allowed to carry out school checks, he said.
But he warned that, however stringent domestic procedures were, it was hard to check out the background of workers who arrived in the UK from overseas.
He called on ministers to "engage urgently" with other countries to increase co-operation.
Jan Berry, chairman of the Police Federation of England and Wales, welcomed Sir Michael's efforts towards ensuring a national intelligence computer system.
"The Federation has consistently campaigned for such a system to be in place to provide co-ordinated, reliable and relevant information across all police forces."
She said adequate training for all police officers would be essential to making the system effective.
"The system must also be straightforward to use and allow easy access to information, while respecting confidentiality issues," she said.
The Bichard Inquiry was set up after it emerged that Humberside police and social workers in Lincolnshire had an extensive list of allegations made against Huntley which were not passed on to detectives in Cambridgeshire.