Over 30 Years: The Mectizan® Donation Program

January 6, 2021

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Our commitment: “as much as needed, for as long as needed…"

For centuries, river blindness (onchocerciasis) plagued remote communities in Africa, Latin America and Yemen, and there was no answer to this affliction.

This all began to change in the mid-to-late 1970s, when Dr. William Campbell of Merck Research Laboratories suggested the use of ivermectin (later named Mectizan) for river blindness in humans. Following the breakthrough lab work by Dr. Campbell, another Merck researcher, Dr. Mohammed Aziz, championed the clinical development of Mectizan. Dr. Aziz led the collaboration with the World Health Organization (WHO) in the early 1980s to design and implement field studies in West Africa that, ultimately, proved the effectiveness of the drug against river blindness.

In 1987, Merck committed to donate Mectizan – as much as needed, for as long as needed – with the goal to help eliminate river blindness.

Mectizan logo set
Full list of partners includes: World Health Organization, the Task Force for Global Health, as well as ministries of health, non-governmental development organizations, academic institutions and local communities in endemic communities.

In order to reach this goal, Merck leaders recognized that many organizations with unique skills would need to work together as a team. To enable this collaboration, Merck established the Mectizan Donation Program (MDP), a ground-breaking public-private partnership. Operating from the Atlanta-based Task Force for Global Health, the MDP coordinates technical and operational activities between Merck, WHO, endemic countries, and a range of public and private stakeholders.

Building on the successful implementation of the river blindness program, in 1998 Merck expanded its commitment to include donating Mectizan for another disease, lymphatic filariasis (LF), also known as elephantiasis, in African countries and Yemen where it co-exists with river blindness. For LF, Mectizan is administered with albendazole, a drug donated by GSK.

In November 2017, in support of new WHO guidelines, Merck announced an expansion of the MDP to reach up to an additional 100 million people per year through 2025 as part of the global effort to eliminate LF.

More than thirty years later, the results of the MDP speak for themselves. Several countries in Africa are making significant progress towards eliminating both diseases. In Latin America, four countries – Colombia, Ecuador, Mexico and Guatemala – have received WHO verification of river blindness elimination. LF has now been eliminated in Togo, Yemen and Malawi. Both river blindness and LF are on WHO’s list of neglected tropical diseases targeted for elimination globally.

Today, the MDP is the longest-running, disease-specific drug donation program of its kind and has been influential in the development of a number of other drug donation programs. And, the MDP’s community-directed strategy used to distribute Mectizan has enabled add-on health services to be introduced in remote communities where health services are limited. The program reaches more than 300 million people in the affected areas annually, with more than 4 billion treatments donated since 1987.

“This pioneering program has changed the face of global health over the past three decades,” said Yao Sodahlon, head of the MDP. “When I visit communities where Mectizan is donated, I can see how the program has helped alleviate suffering and allowed people to live better and healthier lives.”

Mectizan eye chart

What is river blindness?

One of the leading causes of preventable blindness worldwide. Transmitted through the bite of black flies – which live and breed near fast-flowing streams and rivers – and can cause intense itching, permanent skin and eye lesions and, over time, blindness. It has historically been prevalent in remote rural areas of 36 countries (in Africa, Latin America, and in Yemen.)

What is lymphatic filariasis (LF)?

Also known as elephantiasis, LF results in disfiguring swelling in the limbs and genitals. Parasitic infection spread by mosquitoes and damages the human lymphatic system. More than 1.3 billion people are at risk, and 30 percent of those infected live in Africa.

According to Uche Amazigo, former director of the African Programme for Onchocerciasis Control, “by engaging the people, the treatment coverage increased significantly.”

People in the communities are an integral part of the distribution process in 49 countries where Mectizan has been distributed.

Explore our more than 30-year history of helping to bring treatment to those afflicted by river blindness and elephantiasis.

Woman getting water from the river

Dr. William Campbell of Merck Research Laboratories suggests the use of Mectizan (ivermectin) against onchocerciasis (river blindness) in humans.


The first human clinical trials begin in Dakar with the first patient receiving a single dose.


Merck CEO Dr. Roy Vagelos announces the company’s commitment to donate Mectizan to treat river blindness — as much as needed, for as long as needed — the MDP is formed.


The Mectizan Expert Committee meets for the first time to establish the strategy for distribution and the donation review process. Mectizan has been produced at the MSD plant in Haarlem, the Netherlands, since the beginning of the program.


Merck, the MDP Secretariat and WHO establish the Non-Governmental Development Organization (NGDO) Coordination Group for Onchocerciasis Control. NGDOs play a critical role in Mectizan distribution through their work with ministries of health and local communities, expertise in program management, and financial support.


The Onchocerciasis Elimination Program for the Americas (OEPA), formed by the River Blindness Foundation and currently sponsored by The Carter Center, brings together the ministries of health of six countries in Latin America affected by onchocerciasis.


WHO, the World Bank, international NGOs, and 19 African countries partner to create the African Program for Onchocerciasis Control (APOC), providing a structure for financial support and coordination of river blindness control efforts.


Merck begins a partnership with GSK to expand the MDP to include the elimination of LF, commonly referred to as elephantiasis, in African countries and in Yemen.

Merck and the MDP celebrate the 100 millionth treatment in Uganda.


The iconic river blindness statue, “Sightless Among Miracles” by sculptor R. T. Wallen, is dedicated at WHO headquarters in Switzerland. Identical statues are also found at The Carter Center (Georgia, USA), the World Bank (Washington, D.C., USA), the Royal Tropical Institute (Amsterdam, the Netherlands), Merck (New Jersey, USA) and Lions Club International Foundation (Illinois, USA).


In Tanzania, Merck CEO Raymond
Gilmartin celebrates the 250 millionth
treatment distributed.


The Pan American Health Organization passes a resolution calling for the interruption of transmission of river blindness in the Americas by the year 2012.

WHO confirms the potential for elimination of river blindness in some parts of Africa through current treatment strategies.


Merck reaffirms its commitment to the MDP. Merck “will continue to [donate Mectizan] until river blindness becomes a disease of the past,” said Merck CEO Richard T. Clark.


Colombia becomes the first country to apply for WHO certification for the elimination of onchocerciasis transmission after suspending treatment with Mectizan in 2007.


Merck CEO Kenneth C. Frazier commemorates the 25th anniversary of the MDP at a celebratory event in London.


WHO verifies that Colombia has eliminated onchocerciasis, thus becoming the first country in the world to achieve this goal.


WHO verifies the elimination of onchocerciasis in Ecuador. Ecuador worked in partnership with the MDP and a number of other organizations and now becomes the second country in the world to be free of this disease.


WHO verifies the elimination of onchocerciasis in Mexico, the third country in the world to be free of river blindness.

Dr. William C. Campbell, Ph.D., is jointly awarded the Nobel Prize in Physiology or Medicine for the discovery of avermectin, which led to a treatment for river blindness. Dr. Campbell performed his Nobel Prize-winning work at Merck Research Laboratories in Rahway, N.J., where he worked from 1957 until his retirement in 1990.


WHO verifies the elimination of onchocerciasis in Guatemala thanks to a partnership with the MDP and a number of other organizations. With this milestone, four of the six countries in the Americas historically at-risk for river blindness now have verified elimination of the disease.


Togo becomes the first country in Africa recognized by WHO to have eliminated LF as a public health problem.

Merck announces an expansion of the MDP to reach up to an additional 100 million people per year through 2025 as part of the global effort to eliminate LF.


WHO verifies the elimination of LF as a public health problem in Yemen. The Mectizan Expert Committee meets in Togo and presents the Ministry of Health with the Lymphatic Filariasis Elimination Award.


WHO verifies the elimination of LF as a public health problem in Malawi.

Over 30 years later, the results of this program speak for themselves

more than

Billion cumulative treatments

donations to


Through the efforts of a variety of partners, more than 4 billion treatments have been donated to 49 countries in Africa, Latin America, Eastern Mediterranean, Asia, and South Pacific. River blindness transmission has been interrupted – meaning no new cases have been identified – in four of the six affected countries in Latin America and regions in five African countries. The program reaches more than 300 million people annually.

Today, the MDP is the longest-running, disease-specific drug donation program of its kind. See more information.

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“We are humbled by the great work of the alliance of partners to protect future generations from a disease that carries devastating implications for people, families, health care systems and local economies.”

Ken Frazier

Executive chairman of the board

Video documentary – “for as long as it’s needed”

View each video below to explore the history and impact of the Mectizan Donation Program.

1. About the disease

About the disease

2. Discovering a cure

Mectizan video 2

3. Merck’s pledge

Mectizan video 3

4. Community approach

Mectizan video 4

5. Current statistics

Mectizan video 5