No 10 - 2010

MMR vaccination coverage

Coverage was calculated as per 30 November 2009. Starting 1 April 2008, MMR 2 vaccination was advanced to the four-year examination, EPI-NEWS 9/08. Children who were four years or above by 1 April 2008 should still receive the MMR 2 vaccination at 12 years of age. During an eight-year transition period, the MMR 2 vaccination will therefore be administered to two birth cohorts: 4 and 12 years of age.

Childhood vaccination database

The national childhood vaccination database holds person-identifiable data based on the GPs’ settlements with the National Health Service. Thus, the reported coverage only comprises vaccinations administered in Denmark by GPs. For some birth cohorts, vaccination was expected not to have been concluded at the calculation date. In birth cohort 2008, this is the case for MMR 1, and in birth cohort 1997 for MMR 2.

MMR 1

Overall, a slight decrease in MMR 1 coverage was observed compared to the previous report, EPI-NEWS 36/08. Coverage has remained stable at 89%, since 1999, but birth cohorts 2005 and 2006 have a slightly lower coverage of 86-87%, Figure 1. Coverage in birth cohort 2007 was 84%, which may be explained by delayed vaccinations. The highest vaccination coverage was observed on Bornholm, in East Zealand and East Jutland and West Jutland, Table 1.

MMR 2 at 12 years

Overall, MMR 2 coverage remained unchanged compared to the previous report, EPI-NEWS 36/08.

Vaccination coverage for the birth cohorts 1991-1996 was 85-87%, Figure 1. Coverage was 68% in birth cohort 1997, which may be explained by delayed vaccinations.

MMR 2 at four years

In the part of birth cohort 2004 expected to have received MMR 2 by 4 years of age, a 64% coverage was recorded; in the reported share of cohort 2005, coverage reached 61%, Table 2. The overall coverage of birth cohorts was 57% in 2004 and 51% in 2005, Figure 1.

Vaccination age

MMR 1 is administered with considerable delay. Therefore, the overall coverage at 18 months of age is only 70% and it is only at two years of age that the approx. 89% level is reached, Figure 2. Among the vaccinated, only approx. 77% had received MMR 1 at 18 months of age.

Commentary

MMR vaccination coverage remains inadequate given that the set objective states that 95% of all children should receive two MMR vaccinations. Neither for MMR1 nor for MMR2 did coverage exceed 90% for any birth cohort, and - as previously - MMR 2 coverage was generally lower than MMR1 coverage. In birth cohort 1996, which is the first cohort that includes data for both MMR 1 and MMR 2, coverage of both vaccines only reached 85%.

The coverage of MMR 2 at four years is markedly lower than MMR 2 coverage at 12 years. Unfortunately, the current coverage and delay with respect to the recommended MMR1 vaccination time will continually contribute to a weakening of the population's immunity. Over time, the number of unprotected children and adolescents will accumulate, and the risk of e.g. measles outbreaks will increase in Denmark.

The low coverage underlines the importance of vaccinating at the 4-year examination; or, alternatively, to follow-up by administering MMR 2 concurrently with DTaP-IPV revaccination at five years, or when the child is seen for other complaint.

(P. Valentiner-Branth, S. Glismann, A.H. Christiansen, Department of Epidemiology., J. Simonsen, Department of Epidemiological Research)

Individually notifiable diseases and selected laboratory diagnosed infections  

10 March 2010