This supplementary appendix to the article "Facilitating the development of urgently required combination vaccines" by Hausdorff et al. (2024) provides additional information and visual aids to support the main text. It includes: 1. **Figure 1**: A visual representation of the increasing number of pathogens and diseases preventable by vaccination. The figure categorizes these pathogens and diseases into globally recommended vaccines (in bold black font) and those recommended for high-burden contexts, regions, and/or high-risk populations (in plain font). The pathogens are also grouped by age ranges and colored accordingly. Abbreviations for specific pathogens are provided. 2. **Figure 2**: An illustration of the evolution in vaccines recommended by WHO over time, showing the progression of vaccines recommended for use by WHO, by immunization visit. The figure highlights multi-pathogen combination vaccines and their status as either globally recommended or recommended for high-risk and/or regional populations. 3. **Table**: An illustrative example of syndromic combination vaccines, which are designed to prevent multiple diseases that share common symptoms. The table includes specific pathogens such as RSV (Respiratory Syncytial Virus). These supplementary materials enhance the understanding of the article's main points and provide additional context on the development and recommendations of combination vaccines.This supplementary appendix to the article "Facilitating the development of urgently required combination vaccines" by Hausdorff et al. (2024) provides additional information and visual aids to support the main text. It includes: 1. **Figure 1**: A visual representation of the increasing number of pathogens and diseases preventable by vaccination. The figure categorizes these pathogens and diseases into globally recommended vaccines (in bold black font) and those recommended for high-burden contexts, regions, and/or high-risk populations (in plain font). The pathogens are also grouped by age ranges and colored accordingly. Abbreviations for specific pathogens are provided. 2. **Figure 2**: An illustration of the evolution in vaccines recommended by WHO over time, showing the progression of vaccines recommended for use by WHO, by immunization visit. The figure highlights multi-pathogen combination vaccines and their status as either globally recommended or recommended for high-risk and/or regional populations. 3. **Table**: An illustrative example of syndromic combination vaccines, which are designed to prevent multiple diseases that share common symptoms. The table includes specific pathogens such as RSV (Respiratory Syncytial Virus). These supplementary materials enhance the understanding of the article's main points and provide additional context on the development and recommendations of combination vaccines.