Abstract
BACKGROUND: In 2015, Public Health Agency of Canada (PHAC) identified a set of priorities for research and development (R&D) of new and improved human and animal vaccines. Thirty human pathogens were grouped by vaccine development timeline (short: 0-6 years; medium: 7-12 years; long: 13 years or longer) and ranked by R&D priority (high, medium, low). OBJECTIVE: To characterize the vaccine development pathway for these 30 pathogens to inform a 2025 update to PHAC's vaccine R&D priorities. METHODS: For each pathogen, we conducted a targeted search for vaccines authorized in Canada since 2015 using the Health Canada Drug Product Database and Canadian Immunization Guide and for candidates in clinical trials, in the registry, ClinicalTrials.gov (primary completion date of May 1, 2015 or later). Search results were downloaded and filtered by study status, phase and type. For select pathogens, we conducted additional searches in published (PubMed) and grey literature (other trial registries, industry press releases, and Web searches). RESULTS: Seven pathogens had at least one newly authorized vaccine since 2015: three of 13 high-priority (influenza, n=4; Streptococcus pneumoniae, n=2; respiratory syncytial virus, n=3); two of eight medium-priority (herpes zoster, n=1; meningococcal serogroup B, n=1); and, two of nine low-priority pathogens (dengue, n=2; human papillomavirus, n=1). Nineteen pathogens had no authorized vaccine in Canada or elsewhere, although five had candidates in phase 3 trials (Clostridioides difficile, Neisseria gonorrhoeae, Borrelia burgdorferi, norovirus and cytomegalovirus). CONCLUSION: Although some of the pathogens on the 2015 list now have authorized vaccines or candidates in late-stage clinical development, important gaps persist, which will inform PHAC's 2025 vaccine R&D update.