Currently, vaccination coverage among young children is estimated based on 24-month health certificates. While this data source provides satisfactory estimates, it remains slow to reflect changes. The objectives of this study were, first, to validate a new tool, the General Beneficiary Sample (EGB), which would allow for faster estimates of vaccination coverage, and, second, if the results are satisfactory, to estimate and monitor vaccination coverage for mandatory and recommended vaccines in the vaccination schedule. The EGB is a representative sample of beneficiaries of the general health insurance scheme comprising approximately 500,000 people. It allows for linking the sociodemographic characteristics of beneficiaries to their healthcare utilization over time. The study population consists, on the one hand, of children born between 2004 and 2008 for childhood vaccination coverage and, on the other hand, of girls aged 14 to 17 for vaccination coverage against human papillomavirus (HPV) infections. Vaccination coverage estimated using the EGB on the one hand and health certificates on the other is similar for MMR and hepatitis B vaccines but differs for BCG. Hepatitis B coverage (1 dose) at 6 months has increased significantly in the cohort of children born in 2008 (2007: 26.8%; 2008: 55.5%) following the approval of reimbursement for the hexavalent vaccine in March 2008. Coverage at 24 months for the pneumococcal booster7 is increasing for children born between 2004 and 2007 but remains very low (58.8% for the 2006 cohort). Among girls aged 14 to 17 in 2008, 38.2% had started HPV vaccination. Despite certain limitations inherent to the nature of these data (reimbursement data)—notably the difficulty in identifying children vaccinated through the PMI program who are not included in this database—the EGB is a responsive tool that is useful for monitoring vaccination coverage, particularly for new vaccines. (R.A.)