Background
Childhood immunisation is a cost-effective activity in health. Immunisation of children has contributed to reducing child morbidity and mortality. In the last two decades, global deaths from vaccine-preventable illnesses have decreased significantly as a result of immunisation. Similar trends have been observed in Ghana following the introduction of the Expanded Programme on Immunisation. The administration of vaccines is based on the period of highest susceptibility among others. Ghana has long used the proportion of children receiving vaccines and the trends in vaccine preventable illness incidence as performance indicators for immunisation. The addition of timeliness of vaccine uptake as an additional performance indicator has been recommended. This study evaluated the timeliness of vaccine uptake among children immunised at the Komfo Anokye Teaching Hospital, Kumasi, Ghana.

Methods
The study was conducted at the Maternal and Child Health clinic of the hospital between February and March 2012. A representative sample of 259 respondents was selected by simple random sampling. Data collection was by a structured questionnaire and included the examination of Child Health records booklet. Data was entered into a Microsoft Office Access database and analysed using Epi Info Version 3.5.1 2008.

Results
The majority of mothers attended antenatal clinics during pregnancy. An overwhelming majority of babies (98.8%) were delivered in a hospital. About 85% of babies were less than 12 months of age. Mean time taken to reach the clinic was 30 minutes. Vaccine uptake was generally timely for initial vaccines. The proportion of children receiving the vaccines later increased with latter vaccines. Overall, 87.3% of babies received vaccines on time with only 5.3% receiving vaccines beyond 28 days of the scheduled date. Children receiving immunisations services in the same facility as they were born were more likely to receive the BCG vaccine on time.

Conclusions
Vaccine uptake is mostly timely among respondents in the study. The BCG vaccine in particular was received on time among children born in the same facility as the immunisation clinic. There is the need to further examine the timeliness of vaccine uptake among children delivered outside health facilities in Ghana.