NEW DELHI: Health threats globally continue to grow, fuelled by climate impacts, environmental degradation, geopolitical tensions and shifting demographics, said WHO on Monday.
On the occasion of World Health Day 2026, the World Health Organisation (WHO) said these challenges include persistent diseases and strained health systems as well as emerging diseases with epidemic or pandemic potential.
“Science is one of humanity’s most powerful tools for protecting and improving health,” said Tedros Adhanom Ghebreyesus, Director-General of the WHO.
“People in every country live longer and healthier lives on average today than their ancestors did, thanks to the power of science. Vaccines, penicillin, germ theory, MRI machines and the mapping of the human genome are just some of the achievements that science has delivered that have saved lives and transformed health for billions of people.”
Calling on people to renew their commitment to working together and supporting science as the twin engines driving better health, under the World Health Day 2026 theme: “Together for health. Stand with science,” the WHO said human health has been profoundly transformed over the past century, largely due to scientific progress and international collaboration.
The global maternal mortality rate has fallen by more than 40% since 2000, and deaths among children under five have been reduced by over 50%.
Advances in technology, scientific knowledge and skills, and collaboration between different disciplines, sectors and countries continue to turn once-life-threatening health challenges – such as elevated blood pressure, cancer diagnoses or HIV infection – into manageable health issues, extending and improving lives worldwide.
“Across the globe, thousands of scientists – together with organizations such as WHO – are accelerating research and developing policies, tools and innovations needed to protect communities today and safeguard the health of future generations,” the WHO said.
It said that scientific innovations are most powerful when they are widely adopted and used.
The world health body said that every success in improving human health reflects the collective work and collaboration of scientific organizations, policy- makers, heath workers and the public.
Citing a few examples, it said, that before modern anesthesia, surgery meant unimaginable pain. Today, safer medicines, affordable technologies and trained specialists allow life-saving operations to be performed while patients sleep comfortably.
Scientific progress has helped democratize these advances, making safe surgical care accessible across the world, including in many resource-limited communities;
Over the past 50 years, global immunization efforts have saved over 154 million children from infectious diseases. Vaccines have contributed to a 40% reduction in infant mortality, with just one vaccine – the measles vaccine – saving over 90 million children; and
Progress in early screening technologies is transforming health outcomes. From electronic blood pressure monitors to breast cancer screening through mammography, these tools have become life-saving interventions for millions.
WHO said that it continues to identify emerging challenges to human health, bringing together leading scientists and policy-makers to develop norms and standards that protect communities.
For example, WHO’s global air quality guidelines define air quality levels needed to safeguard health from risks such as respiratory infections, asthma, chronic obstructive pulmonary disease (COPD) and lung cancer. WHO’s drinking water standards ensure that the water from our taps is safe, helping prevent diarrheal diseases, including deadly ones such as cholera.
“Science transforms uncertainty into understanding and reveals the pathways to protect and heal our communities,” said Dr Sylvie Briand, WHO Chief Scientist.
“Without the clarity of rigorous scientific inquiry, we risk being led by bias and misconception - and too often toward treatments that fail us or even place us in harm’s way. Today, we must stand together with science so that our collaboration is sustained, supported and enhanced for the better health of generations to come.”
WHO emphasized that science must continue to guide health decision-making at all levels. "Achievements in global health show that when countries unite behind science, they not only respond to crises more effectively but also build stronger, more equitable health systems for the future. WHO calls on governments, institutions and individuals to continue supporting and collaborating on science and ensuring that evidence-based approaches guide health policies and everyday decisions," it said.