Vaccines: childhood immunization coverage falling in some European countries

Following decades of general improvement in childhood immunization coverage across the European Union, a slowdown or reversal of this trend has been observed in recent years in many countries and for several vaccines. The most marked drops concern vaccinations against Haemophilus influenzae type b (Hib) and poliomyelitis, followed by the pneumococcal vaccine. Although many of these declines occurred between 2019 and 2022, the authors point out that they cannot be attributed solely to the impact of the pandemic. This is the finding of a study recently published in The Lancet Regional Health Europe and conducted by Leonardo Villani, Luigi Russo, Francesco Andrea Causio, Cosimo Savoia, Roberta Pastorino, Chiara De Waure, Walter Ricciardi and Stefania Boccia.

“We analysed the WHO/UNICEF estimates of immunization coverage for all 27 EU countries from 1980 to 2024, taking into account seven indicators relating to the vaccinations administered in the first year of life: diphtheria-tetanus-pertussis (DTP-3), hepatitis B, Haemophilus influenzae type b, measles, pneumococcus, poliomyelitis and rubella” explains Professor Villani, Associate Professor of General and Applied Hygiene at UniCamillus-Saint Camillus International University of Health and Medical Sciences. “The first key finding is that, looking at the entire period covered, the European picture remains largely positive: out of 183 country-vaccine time series analysed, 128 showed long-term growth. This confirms the remarkable results achieved by European vaccination programmes over the last forty years.”

However, Villani points out that an analysis of the most recent trends paints a less favourable picture: “We have identified 119 recent downward trends and 64 upward trends. In particular, 16 EU countries have shown a recent downward trend for at least four of the seven indicators analysed. Bulgaria, Cyprus, Ireland, the Netherlands, Romania and Sweden have shown a recent downward trend for all seven indicators; Germany and Spain for five indicators’.

Recent drops are mainly related to vaccinations against Haemophilus influenzae type b (which can cause meningitis) and poliomyelitis – for both, 20 countries show a recent downward trend – followed by hepatitis B, with 18 countries, and DTP-3, with 17 countries. For measles and rubella, the recent picture appears relatively more favourable, although it is not uniformly positive across all member states.

It is important to note that the study allows to quantify trends in terms of direction and average annual change in coverage over time, but does not identify the causes of the observed changes. Many of the most recent downward trends began between 2019 and 2022, i.e. during the pandemic or in the period immediately following it. This finding is consistent with the hypothesis that difficulties in delivering routine vaccination services played a role in this drop, concludes Villani, “but our study design does not allow to attribute the decline causally to the pandemic: barriers to access, inequalities, vaccine hesitancy, misinformation, organisational differences and the specific characteristics of individual national programmes may also be contributing factors.”

As far as Italy is concerned, the situation is more balanced than that of many other European countries. In the analysis of the most recent trends, four indicators show an increasing or slightly increasing trend (DTP-3, hepatitis B, measles and rubella), whilst three show a decreasing or slightly decreasing trend: Hib, pneumococcal disease and poliomyelitis.

Analysing the figures for 2024 (the latest year available in the study), the WHO/UNICEF estimates indicate that Italy has a coverage rate of 94 % for DTP-3, hepatitis B and poliomyelitis; 95 % for Hib, measles and rubella; and 90 % for the pneumococcal conjugate vaccine. These figures therefore show generally very positive levels, but only three indicators reach or exceed 95 %.

Over the long term, Italy has shown average increases in coverage for DTP-3, Hib, measles, pneumococcal disease and rubella; for hepatitis B and poliomyelitis, however, the overall average trend remains essentially stable. The results therefore highlight that the progress made over the years is not irreversible: even modest reductions or stagnations in coverage, particularly if concentrated in specific areas or population groups, can create pockets of susceptibility and facilitate the re-emergence of vaccine-preventable diseases.

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