Vaccination coverage: a key indicator for measuring the impact of a vaccination program

After a vaccine is added to the immunization schedule, vaccination coverage data help ensure that this addition has actually taken effect. These data are therefore useful for determining whether a vaccination program is being properly implemented. They are essential because maintaining high vaccination coverage is a key factor in controlling vaccine-preventable infectious diseases.

Increase in vaccination coverage at 24 months for children born before 2018

The 24-month health certificates are used to measure infant vaccination coverage for all vaccines, except for the meningococcal C vaccine, for which data come from the National Health Data System (SNDS). The data from health certificates analyzed in 2020 pertain to children who reached 24 months of age in 2018 and are therefore not affected by the expanded vaccination requirements introduced for children starting in January 2018.

Vaccination coverage at 24 months for children who reached 24 months of age in 2018:

• remains stable at a very high level and exceeds the 95% target for DTP, pertussis, and Haemophilus influenzae type b.

• are above 90% but below 95% for hepatitis B and pneumococcal disease,

• continue to rise but remain at insufficient levels:

  • 90.9% for the first dose (+1.3 percentage points) and 83.4% for the second dose of the measles-mumps-rubella vaccine (+3.1 percentage points)

  • 84.5% for the second dose of the meningococcal C vaccine administered at 12 months (+5.9 percentage points).

Children subject to mandatory vaccination born after January 1, 2018: 95% target nearly reached for the first dose of MMR

Based on data extracted from the SNDS capturing nearly all vaccine doses administered through the end of June 2020, Santé publique France estimated vaccination coverage for children born between January and March 2018 at 24 and 27 months of age.

These analyses show that vaccination coverage is approaching the 95% target for the first dose of the MMR vaccine among children born in the first quarter of 2018 (93.7% at 24 months and 94.4% at 27 months). However, they show that coverage for the second dose of the
MMR vaccine among these children (80.6%) remains well below this target. Finally, the analyses show continued improvement in coverage for the second dose of the meningococcal C vaccine, which is approaching 90% (88.9% at 24 months and 89.2% at 27 months).

While caution is warranted when comparing data derived from health certificates with those extracted from the SNDS, these initial 24-month estimates already highlight the impact of the expanded vaccination requirements for vaccines administered in the second year of life—specifically the first dose of MMR and the second dose of meningococcal C vaccine—rising from 90.9% (CS24) to 93.7% (SNDS) and from 84.5% to 88.9%)

Vaccination coverage for children over the age of 2

The uptake of HPV vaccination, which is not mandatory, continued to rise in 2019, with an increase of 5.8 percentage points for the first dose (34.9%) and 4.2 percentage points for the second dose (27.9%) compared to 2018. These increases are higher than those observed between 2017 and 2018 (2.9 percentage points and 2.3 percentage points, respectively). They partly reflect the positive impact of lowering the vaccination age to 11 years, but could also be the result of increased communication efforts regarding vaccination in recent years. Despite these increases, vaccination coverage against human papillomavirus infections among young girls remains at moderate and insufficient levels.

15% of healthcare professionals have yet to be vaccinated against measles

To obtain recent national estimates of vaccination coverage among healthcare professionals for recommended vaccinations, a study was conducted in healthcare facilities by Santé publique France in collaboration with the Nouvelle-Aquitaine Center for Support in the Prevention of Healthcare-Associated Infections (CPias) as part of the national mission “Support for Actions to Prevent Healthcare-Associated Infections” and the CPias network.

According to this study, in 2019, vaccination coverage among healthcare professionals in healthcare facilities was 73% for measles, 54% for pertussis, and 26% for chickenpox. While vaccination coverage for chickenpox has remained stable since 2009, it has increased by 23 percentage points for measles and by 39 percentage points for pertussis. Taking into account the history of measles (37% of healthcare professionals) and chickenpox (87% of healthcare professionals), these coverage estimates suggest that 15% of healthcare professionals in healthcare facilities still need to be vaccinated against measles and 10% against chickenpox.

These estimates complement the previously published estimates on influenza vaccination, which indicated a vaccination coverage rate of 35% among healthcare professionals in healthcare facilities. Furthermore, in this survey, more than 70% of healthcare professionals stated they were “very supportive” or “somewhat supportive” of mandatory vaccination against measles and pertussis for their profession.

“The unprecedented COVID-19 pandemic must not cause us to forget to take care of our health in all its aspects. It is important to keep your vaccinations up to date to protect yourself and others,” concludes Daniel Lévy-Bruhl, head of the Infectious Diseases Unit at Santé publique France.