WHO Immunization Director Issues October 2026 Message

Behind every dose, a decision: evidence, equity and health security

From 5 to 8 October, the Strategic Advisory Group of Experts on Immunization (SAGE) met to review the evidence on vaccines against human papillomavirus (HPV), diphtheria, yellow fever, mpox and polio, and to consider the role of vaccination in the ongoing Bundibugyo virus disease outbreak.

Every year, vaccines save millions of lives. But behind every dose is a series of decisions, and many of them are hard. Which groups should we reach first? How should we respond when an outbreak strikes? When is new evidence strong enough to change what we recommend? And how do we protect the programmes we have built when budgets are under pressure? These questions were at the heart of SAGE's deliberations .

They are not only immunization questions. They are health security questions. When routine coverage is high, outbreaks are less likely. When surveillance is strong, we detect threats early. When vaccine policies are clear, countries can act quickly and decisively. Wherever there are gaps in protection, communities are left exposed. And diseases do not stop at borders.

Countries have made real progress, including by reaching millions of children who missed their vaccines during the pandemic. By the end of 2025, more than 95 million girls had received HPV vaccine, surpassing the target set for that year. But we cannot be complacent. Too many children are still not vaccinated at all, or do not complete their recommended vaccine series. And financial pressures are making it harder for country immunization programmes to close these gaps while holding on to the protection they already deliver. This is especially a challenge in countries with rising birth cohorts, many of which are in the African continent.

This is exactly why SAGE matters. Its independent review of the evidence underpins the WHO's vaccine recommendations. Countries rely on this guidance to set priorities and make decisions transparently. Scientific rigour is non-negotiable. But so is a clear understanding of the real-world conditions in which immunization programmes operate.

HPV shows what evidence-informed policy can achieve. Today, 165 countries (85%) have introduced HPV vaccine, bringing the elimination of cervical cancer within reach. Yet global HPV vaccine coverage, at 33% in 2025, is still far below the 90% target. Having reviewed the latest evidence, SAGE concluded that a single-dose HPV vaccine schedule for girls aged 9 to 14 years is the most efficient way to reach it. A single dose can be used up to 30-year-old and for countries, this means being able to extend protection to more girls and young women while making the best possible use of vaccine supplies and programme resources.

SAGE also examined the rise in diphtheria outbreaks. These outbreaks are a warning sign: they reveal major gaps in immunity wherever coverage with the primary series of diphtheria-containing vaccines is low or booster doses are missed. The experts were clear that diphtheria outbreak response resources should be focused on case detection, diphtheria antitoxin therapy for cases, and for cases and close contacts both antibiotics treatment and vaccination. Vaccine outbreak response campaigns have a limited role for stopping transmission and preventing cases. If deployed should be done in the early phase of an outbreak to get ahead of the spread. More important is to deploy immunization efforts toward a serious plan for shoring up primary and booster routine vaccination. Diphtheria outbreaks are best addressed by establishing lasting protection via strong routine immunization services which endure long after a campaign ends.

For yellow fever, SAGE considered how fractional doses (one-fifth of a standard vaccine dose) can stretch protection further when demand outstrips resources. It concluded that fractional doses may continue to be used in outbreaks under supply constraints and newly recommended their use in certain preventive campaigns where supply, financial or programme constraints would otherwise hold back timely vaccination. For routine and catch-up vaccination in young children, the standard dose remains the recommendation. These distinctions matter: how a vaccine is best used depends on both the evidence and the setting in which it is given.

Mpox remains a concern, even though major outbreaks have subsided. SAGE reviewed vaccination for people at risk during outbreaks and the possible role of preventive vaccination, before cases occur, for those at high risk of infection or severe disease. It especially noted the specific critical evidence gaps in epidemiology and vaccination, without which a policy recommendation for preventive use in children is not possible. It also highlighted the need for more evidence in pregnant women and people with severe immunocompromise.

On polio, with wild poliovirus transmission continuing in Pakistan and Afghanistan, SAGE's message was unequivocal: countries currently providing fewer than three doses of inactivated poliovirus vaccine through routine immunization should move without delay to a three-dose infant schedule.

The ongoing Bundibugyo virus disease (BVD) outbreak brings the urgency of all of this into sharp focus. SAGE expressed deep concern at how difficult the outbreak has been to control, and at the number of young children who have died. It reaffirmed its earlier recommendation that, in the BVD context, Ervebo vaccine, licensed for ebola virus disease, be used only within research protocols. The TUMAINI randomized controlled trial, which started on 23 October 2026, is expected to generate urgently needed evidence on whether any of the vaccine candidates, including Ervebo, have efficacy against Bundibugyo virus disease. Supporting that research, while meeting the immediate needs of affected communities, is essential, both for the decisions needed now and for those that will be faced in the future. Hence, SAGE reiterated the urgency of generating robust evidence on vaccine efficacy through the TUMAINI randomized controlled trial for informing future policy vaccine recommendations and protect affected communities.

One lesson ran through the entire meeting: recommendations must evolve as the evidence and public health needs evolve. SAGE weighs what we know, is transparent about what we do not yet know, and considers the consequences of acting, and of waiting. That advice is never more valuable than when countries face difficult choices about how to use limited resources.

But recommendations alone do not protect anyone. Their impact depends on countries and partners putting them into practice, supported by strong national immunization technical advisory groups. And we must safeguard the vaccines already in national programmes. Doing so strengthens countries' ability to prevent endemic disease and outbreaks, respond to emerging threats and protect the gains that millions of health workers have worked so hard to achieve. Those gains are measured in over 154 million lives saved and hundreds of millions of healthy years enjoyed.

I want to thank the members of SAGE, its Working Groups and the many experts whose commitment made these intensive deliberations possible. Their work gives countries a strong foundation for action. The shared task now is to now turn this evidence into effective, equitable national immunization policies, so that the people who need protection most are the ones who receive it.