Virus-like particles (VLPs) mimic key structural features of native viruses while lacking a replication-competent viral genome, combining favorable safety with multivalent antigen presentation and strong immunogenicity. Yet, how VLP design influences the quality and persistence of adaptive immunity remains incompletely understood.

Advances in the development, manufacture, and testing of biological products, along with the application of the 'Replacement, reduction and refinement,' have driven a paradigm shift in the establishment and application of biological reference standards (BRS) for vaccine quality control and evaluation. Traditional WHO International Standard(s) (IS), historically used for potency harmonization, now face multiple challenges stemming from vaccine diversity, platform complexity, and other factors.

COVID-19 showed that rapid vaccine development and roll-out, while lifesaving, can still yield large, avoidable harms when equity is not considered from the outset. Disparities in vaccine timing and coverage, especially in low-resource settings, amplified health and economic burdens, highlighting the need for preparedness frameworks that combine speed with fairness.

The emergence of epidemic-prone diseases continues to pose a threat to global health. Vaccine stockpiles allow effective and timely response to outbreaks. Global stockpiles have been established for multiple vaccines, but stockpile management has evolved in recent years, both in the number of globally managed stockpiles and in stockpile strategy, from a reactive to a more integrated approach bridging with preventive strategies.

Routine meningococcal vaccination campaigns have substantially reduced the burden of invasive meningococcal disease in pediatric individuals, leading to relative increases in burden in older age groups. There is a need for safe, effective meningococcal vaccines that can be used across broad age ranges. MenACYW-TT, a quadrivalent tetanus-toxoid-conjugate meningococcal vaccine indicated for individuals aged ≥6 weeks, is one such option.