Tedros Adhanom Ghebreyesus is director-general of the World Health Organization.

The United States has been a vital partner to the World Health Organization since its creation in 1948. Together, we have worked to improve the lives of hundreds of millions of people around the world.

If the United States steps back on that essential work, we shouldn’t just think in terms of who will be hurt but also what will be lost. Why? Because the consequences affect everyone.

The covid-19 pandemic has starkly revealed how we need more international cooperation to address global health crises, not less. Not only are we far from addressing all the risks that this insidious virus presents, but the vast majority of people remain susceptible to infection.

Consider the vital role that international cooperation is already playing around the development of a covid-19 vaccine. This began almost as soon as the coronavirus’s sequence was shared online, and there are now 141 vaccines in development. Leading candidates may be only months from success. Of course, there is no guarantee of full protection, but we are hopeful.

Additionally, the world remains highly vulnerable to the next emerging threat. We are already fighting the less-visible pandemic of antimicrobial resistance. This causes nearly 50,000 U.S. deaths annually and half a million more globally. Within 15 years, without effective antibiotics, we face the prospect of a world without open-heart surgery or hip replacements given the risk of life-threatening sepsis.

The WHO has proudly played a leading role in several public health achievements over the past 72 years. Smallpox has been defeated, and polio faces imminent eradication. Many countries have eliminated measles and halted mother-to-child transmission of HIV. Innovative partnerships have led to vaccines against meningitis and Ebola. In today’s interconnected world, responding to public health emergencies — from Zika in Brazil to Ebola in eastern Congo — remains a top priority.

The United States has been with us at the forefront of these outbreaks. Without U.S. participation, this progress will undoubtedly be slowed and vital programs decimated.

Consider the WHO’s program on neglected tropical diseases, which the U.S. Agency for International Development funds at $6 million annually. Since 2002, tens of millions of people have been treated for trachoma — and spared blindness. Elephantiasis, which afflicts 120 million people in 72 countries, was eliminated in Yemen and Kiribati in 2019. And for nearly 900 million children infested with worms, deworming is the most important factor in enabling children to receive an education and for girls to graduate from secondary school.

The community fighting these diseases is much bigger than the WHO. But without the WHO, it cannot access the drugs that are the foundation of the program. This is because only the WHO can operate the global drug-review process — a prerequisite for six pharmaceutical companies across 31 countries to donate to countries in need. To date, these drugs yielded nearly 3 billion treatments, valued at nearly $26 billion.

Moreover, only the WHO has the ability and institutional authority to certify the elimination of infectious diseases such as smallpox. How else can we know — and trust — that a disease is finally gone and move on to other priorities? Trachoma, still affecting 142 million people, is on target to be wiped out within 10 years — but we cannot just press the pause button and resume play when funding comes back. We risk backsliding on years of progress.

More broadly, the WHO is working to ensure the world does not repeat the experience of this pandemic. That requires making people healthy rather than simply keeping diseases at bay.

We recognize that everyone has the right to health, to accurate and timely information about health threats, and to share in scientific advances — including covid-19 vaccines. We also recognize that ethnic minority groups are more likely to suffer co-morbidities such as heart disease, hypertension, diabetes and obesity, and are more likely to lack affordable heath care, multiplying their risk of death.

In addition, many people living on low incomes are disadvantaged by lack of clean water, effective sanitation, adequate electricity and decent living conditions. Investments to correct these deficiencies would yield huge advances in well-being, life expectancy and reduced child mortality. As we wait for a covid-19 vaccine, we can begin such reforms now.

Improving global health requires providing all people with the services they need at a price they can afford. Well beyond contagion, that means addressing chronic diseases, maternal and child health, palliative care and rehabilitation.

To get there will require human resources: expanding the number of skilled doctors, nurses and community health workers. And it requires addressing pharmaceutical supply and introducing funding options that ensure affordable access to both primary and hospital-based care.

The WHO’s constitution redefined health as not just the absence of disease, but the presence of physical, emotional and mental well-being. Investing in public health isn’t a matter of charity. This helps everyone — not just Americans, but all people in all countries. We hope the United States will keep working with the WHO so we can jointly continue the important progress we have made. There is so much more we can do together.

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