Countries facing tighter immunisation budgets should protect vaccines already being delivered through national programmes, WHO’s advisers have warned, as governments weigh expanding services against maintaining existing coverage.
The warning extends beyond delays to new vaccines. At an October 13 briefing, WHO officials said losing ground in established programmes could expose more people to preventable disease and undermine trust in vaccination services.
Dr Kate O’Brien, WHO’s immunisation director, said countries now have access to an increasingly broad range of vaccines, but their budgets cannot necessarily support every product available, even with Gavi assistance.
Decisions therefore need to account for disease burden, community needs, fairness and the practical ability to deliver vaccination. A vaccine introduction can compete for resources with reaching children who have already missed the basic schedule.
O’Brien said more than 30 diseases were now preventable through vaccination. Around 13 to 14 vaccines were recommended for every country, with others intended for particular regions or population groups. That expanding range creates more options for governments, but each introduction brings delivery requirements as well as a purchase price.
For Nigeria, these choices arise alongside persistent difficulties reaching underserved communities and continued work against vaccine-preventable outbreaks. The briefing did not identify a Nigerian vaccine programme being cancelled or disclose a Nigeria-specific funding gap.
O’Brien said funding shortfalls, both domestic and within Gavi’s current strategic period, would require difficult prioritisation. SAGE’s advice was to make maintaining vaccines already included in national programmes a top priority.
Gavi’s financing arrangements are also changing. In a July 2026 presentation, the alliance described moving from applications for individual vaccine programmes to a set country budget for the 2026–2030 period.
The presentation distinguished guaranteed support for a core set of vaccines from discretionary funding, which may not meet a country’s full needs. It also described a reduction in overall cash support. The arrangement is intended to make funding more predictable and give countries greater responsibility for choosing priorities.
Gavi’s September funding guidelines provide a framework for planning vaccine and cash support, including country applications and access to outbreak assistance. Predictability does not, however, mean that the available allocation will cover every planned expansion.
National immunisation technical advisory groups, or NITAGs, are expected to help governments evaluate these choices. Their role includes assessing scientific evidence and advising on which programmes offer the greatest benefit under local conditions.
Professor Anthony Scott, SAGE chair, said many of these committees were still strengthening their capacity. They were being asked to review evidence and track funding in a complicated environment, with unequal access to the data needed for decisions.
These deliberations are already taking place elsewhere in West Africa. In late September discussions, Sierra Leone’s NITAG and partners reviewed existing vaccines and possible introductions for its Gavi application. The exercise considered different sequencing and investment scenarios for 2026–2030.
At the WHO briefing, O’Brien said preserving gains mattered for public confidence as well as disease prevention. Families’ trust could be affected if programmes that had become available could no longer reliably deliver their promised protection.
The scale of the delivery task is substantial. WHO reported in April that the Big Catch-Up initiative reached 18.3 million children across participating countries between 2023 and 2025. In Nigeria, two million previously zero-dose children received a first diphtheria-containing dose, alongside 3.4 million IPV doses.
Sierra Leone’s preparatory workshop used evidence collection matrices to compare possible introductions, implementation timelines and available research. Participants also reviewed programme performance and opportunities to improve existing vaccination. The work was intended to produce recommendations for the country’s Gavi application, alongside plans for preventive campaigns.