RESUMEN
INTRODUCTION AND OBJECTIVE: Regular monitoring of the measles, mumps, and rubella (MMR) vaccine uptake quickly exposes immunity gaps in the population. In Poland, the first dose of the MMR vaccine is mandatory for children between 13 and 15 months of life. This study aimed to assess the uptake of the first dose of MMR vaccine in 380 administrative counties in Poland in 2020, as well as to analyze the MMR vaccine uptake trends in 2013-2016-2020. MATERIAL AND METHODS: This study is an epidemiological retrospective national registry-based analysis. Data on mandatory childhood vaccinations in all 380 counties in Poland were collected from the epidemiological reports of the State Sanitary Inspectorate territorial representatives. MMR vaccine uptake was calculated as the percentage of children who received the first dose of MRR vaccine to all children subject to mandatory vaccination in the county. RESULTS: The uptake of the first dose of MMR vaccine decreased from 99.4% in 2013, to 95.5% in 2016 and 91.9% in 2020. In 2013, 93.2% of countys MMR vaccine uptake level reached the herd immunity level, followed by 77.1% of counties in 2016 and only 38.3% of countys in 2020. In 2020, two counties reached complete (100%) MMR vaccine uptake, and the lowest MMR vaccine uptake was 63.88%. Of the 380 counties in Poland, in 226 (61.1%) the MMR vaccine uptake level was lower than the herd immunity level, and a downward trend was observed. MMR vaccine uptake decreased with an increased number of residents in a county (r= -0.35; p<0.001). CONCLUSIONS: This study revealed that in 61% of administrative regions in Poland, the MMR vaccine uptake was below the herd immunity level. Regional differences in the MMR vaccine uptake were observed. A significant decrease in MMR vaccine uptake between 2013 - 2020 poses a risk of measles outbreaks.
