The paper by Granerod et al¹ shows how children seemed to have been “lost” when the Child Health Information Systems (CHISs) were interrogated to provide the routine immunisation statistics (COVER). This was at a time when the reports changed from being based on a resident population to being based on the primary care trust (PCT) responsible population, i.e. those children who were patients of the PCT’s GPs, but not necessarily resident within the PCT’s geographical boundaries.² The United Kingdom has probably the most accurate and timely system in the world for monitoring immunisation uptake.³ Most other countries rely on either knowing the numbers of doses of vaccine administered or on representative surveys.^4,5 It is of concern that this system was compromised, but the trend of improvement in accuracy reported by the authors is encouraging. However, currently (April 2006), 10 of the 31 PCTs in London are unable to produce any COVER statistics because they are in the process of installing new “interim” CHISs.⁶

What the authors do not mention is that the CHISs are also frequently used to generate appointments for vaccination. This is particularly so in areas such as …