The "Red Book" is one of the things they are planning on replacing with online system. While it could be done online, given the amount of people who like to see the Red Book I'd imagine it will be tricky. In addition to pre and post natal care, we've used them to demonstrate up to date immunisations for Nurseries and Child Care, including at Kids Clubs abroad.
Hate to say it but for harassed parents and others, I think the Red Book is probably a very good and robust system.