Assessing vaccine introduction and uptake timelines in Gavi-supported countries: are introduction timelines accelerating across vaccine delivery platforms?

Background Previous studies identified factors influencing regulatory approval to introduction timelines for individual vaccines. However, introduction and uptake timelines have not been comprehensively assessed across the portfolio of Gavi-supported vaccines.Methods We analysed median times between introduction milestones from vaccine licensure to country introduction and uptake across six vaccine-preventable diseases (VPDs), three delivery platforms and 69 Gavi-supported countries. Data were gathered from public, partner and manufacturer records. VPDs and prequalified vaccines analysed included Haemophilus influenzae type b (DTwP-HepB-Hib, pentavalent), pneumococcal disease (pneumococcal conjugate vaccine, PCV), rotavirus diarrhoea (rotavirus vaccine, RVV), cervical cancer (human papillomavirus vaccine, HPV), polio (inactivated polio vaccine, IPV) and meningococcal meningitis (meningococcal group A conjugate vaccine, MenA).Results Median time from first vaccine licensure to first Gavi-supported country introduction across VPDs at a ‘global level’ (Gavi-supported countries) was 5.4 years. Once licensed, MenA vaccines reached first introduction fastest (campaign=0.6 years; routine immunisation (RI)=1.7 years). Most introductions were delayed. Country uptake following first introduction was accelerated for more recently Gavi-supported RI vaccines compared with older ones.Conclusion Factors accelerating timelines across delivery platforms included rapid product prequalifications by WHO, strong initial recommendations by the WHO Strategic Advisory Group of Experts (SAGE) on Immunization, achieving target product profiles on first vaccine licensure within a VPD and completing several VPD milestones at a global level prior to licensure. Milestones required for introduction in Gavi-supported countries should start prior or in parallel to licensure to accelerate uptake of vaccines delivered through diverse delivery platforms.