Research Trends of Vaccination-Related Systematic Reviews, 2011–2023: A Bibliometric Analysis

Systematic reviews (SRs) reflect the best available evidence for informing vaccination recommendations. This study presents a bibliometric analysis of vaccination-related SRs aiming to uncover research trends. Vaccination-related SRs published from 2011 to 2023 in MEDLINE, Embase, the Cochrane Library and the Living Overview of Evidence database were considered. Trends over time, disease/pathogen, topic, population, geographical location, accessibility, methodological quality, and overlap were descriptively analyzed using R. A total of 2275 SRs were identified, most of which were freely accessible (n = 2083, 91.7%). The annual number of published SRs increased more than twelvefold from 2011 to 2023. COVID-19 (n = 861, 37.8%), influenza (n = 328, 14.4%), Human papillomavirus (n = 248, 10.9%), and pneumococcal disease (n = 152, 6.7%) were the most frequently addressed diseases/pathogens. Efficacy/effectiveness (n = 1066, 46.9%) and safety of vaccines (n = 812, 35.7%) were the most common topics. The methodological quality of SRs on intervention topics (n = 1376) was mostly critically low (n = 1155, 84.0%). Several SRs were identified that covered similar diseases/pathogens, topics and populations, indicating duplication and overlap, particularly for COVID-19. Our analysis showed a large increase in the number of published vaccination-related SRs. The results provide a basis for understanding the current state and priorities in vaccination research and decrease the overlap potential in newly developed SRs.