For every child, everywhere
Twenty-five years ago, working as a paediatrician in Cambodia, I witnessed a young boy die from complications of measles. From a subsistence farming family who’d had to raise money to travel to hospital, he arrived too late to be saved. Vaccination could have prevented him falling ill in the first place – but his parents didn’t understand about vaccines and the health system didn’t know he existed.
That was my first measles patient, but sadly not my last. This story has repeated over the decades of my practice, along with cases of diphtheria and tetanus – all preventable by vaccines. And we know that this story repeats itself across the world, to this very day: from Sudan where over 70% of health facilities in conflict-affected areas have stopped functioning - to northern Nigeria, where community health workers navigate insecurity to reach children who have never been to a clinic - to Hackney, East London, where one in three children haven't received their first measles vaccine by age two.
The journey of a vaccine starts with brilliant British science, from Edward Jenner's smallpox vaccine to the Oxford-AstraZeneca COVID-19 vaccine that provided 2.9 billion doses to 180 countries. It passes through the complex world of manufacturing and market shaping where the UK has pioneered innovative finance instruments, like the International Finance Facility for Immunisation, which has mobilised over US$10 billion for vaccines.
Vaccines work
Few achievements in modern medicine come close to matching the transformative impact of routine childhood immunisation programmes since their introduction 50 years ago. 154 million lives saved – that is six children every minute of every year over five decades. Global infant mortality has been reduced by 40%. In Africa, it’s over 50%. Four-five million deaths continue to be prevented every year. Vaccines are public health’s best buy, delivering US$54 in health and economic benefits for every US$1 spent.
Today as we kick off World Immunisation Week, these extraordinary achievements are a cause for celebration.
But it’s also a wake-up call.
The children we are leaving behind
This year’s theme for World Immunisation Week is, “For every generation, vaccines work". Yet in 2024, 14.3 million infants did not receive even a single dose of vaccines. These are the "zero-dose" children, the ones that health systems never reach. They live in places scarred by conflict, poverty, and fragility. More than half live in just ten countries. A quarter of the world's infants live in 26 countries affected by humanitarian crises, yet they account for half of all unvaccinated children globally.
Each of these children have names, families who love them and futures that are being stolen by preventable disease.
It takes a village, and a system
The journey doesn’t end when a vaccine rolls off the production line. It doesn’t end when a vaccine leaves a distribution centre in cold storage and travels with a community health worker for many kilometres, risking vehicle breakdown or even assault or ambush.
It ends when a drop is placed in a child’s mouth or injected into their arm. It ends in a village or hamlet without electricity, in a nomadic community or in a displacement camp where families have fled with nothing. That last mile is where equity is won or lost.
Bringing vaccines to these children means bringing health systems to their communities – often for the first time. The community health worker can check for malnutrition, diarrhoea or other problems. They can advise the parents on nutrition and breastfeeding. All of this adds to the transformative power of immunisation programmes.
Save the Children works in more than 100 countries to reach the children who conventional health systems miss. In Sudan, we work in partnership with Gavi, The Vaccine Alliance, to deliver vaccines in hard-to-reach areas during active conflict. In Ethiopia, we work alongside community and faith-based organisations to find zero-dose children in remote districts and amongst communities on the move.
We know, from decades of experience, that reaching the last child requires trusted local partners, integrated services delivered through strong and resilient primary health care systems and sustained political commitment.
It’s a UK story too
Here is what many people don't realise: the UK is facing its own immunisation challenges. In January 2026, the UK lost its immunisation status. England recorded 2,911 confirmed measles cases in 2024, the highest in over a decade. A child died from measles in 2025. Not a single routine childhood vaccine in the UK meets WHO's 95% coverage target.
The drivers are familiar to anyone who works in global health: access barriers, misinformation, underfunded services, and deepening inequality. The gap in MMR coverage between the most and least deprived communities in England has widened from one to almost eight percentage points. The children missing out are, as always, the poorest.
Global and domestic immunisation are not separate agendas. Disease does not respect borders. Investing in vaccines abroad protects children at home. And the lessons we learn reaching zero-dose children in conflict-affected settings and building trust in remote marginalised communities can inform how we reach under-vaccinated communities in our own cities.
Our message to Parliament
As part of World Immunisation Week, we are joining our partners to tell Parliamentarians the story of the vaccine journey. Our ask is simple.
Protect the UK's £1.25 billion pledge to Gavi and champion the Gavi 6.0 strategy to reach 500 million more children by 2030. Support the UK's world-class vaccine research and development ecosystem and reverse the decline in funding for neglected disease research. Engage with the regional vaccine manufacturing agenda, which is fully aligned with the UK's New Approach to Africa. And invest in the NHS Vaccination Strategy to reverse vaccine hesitancy at home.
The parents I met 25 years ago wanted the same as any mother or father: for their children to grow up healthy. That’s still the challenge today. For every generation, vaccines work. But only if we learn from the past, can we ensure we reach every child in the future.
