Children who are unvaccinated at one year of age are very unlikely to complete the course of primary childhood vaccines by five years of age, suggests a new study.
The study, published in the journal Vaccine, examined inequalities in childhood vaccination timing and completion of the five-in-one vaccine (diphtheria, tetanus, pertussis, polio and Haemophilus influenzae type b (DTaP/IPV/Hib)) in London, assessed by ethnicity, deprivation and area.
Vaccination histories for 315,381 children born between March 2001 and April 2010 were extracted from nine London health service areas, grouped into first and fifth birthday cohorts.
Vaccine coverage of three doses at one year of age was 86.8 per cent (159,325/183,464). Overall, 91.2 per cent of children fully vaccinated by one year of age had received timely vaccination (third dose by six months of age).
Among children completing vaccination by one year, Somali and Bangladeshi children were less likely to have received three doses of DTaP/IPV/Hib by six months of age compared with white-British children (-11% and -5% respectively).
Compared with white-British children, children of Polish, Somali and Caribbean ethnicities were less likely to return for their preschool booster.
Within the fifth birthday cohort, only 2.3 per cent who were completely unvaccinated (575/25,095) at age one year were fully vaccinated by age five.
Higher proportions of partially vaccinated (one or two doses) children at age one year went on to be fully vaccinated by age five (26% and 58.7%, respectively).
These inequalities suggest that tailored approaches may be required to target specific groups to improve vaccine uptake, the authors said.