Key to vaccine diplomacy---extinction

Unfortunately, beginning around 2015, we started to see unexpected and fundamental changes leading to a new order in which infectious and tropical diseases either emerged or returned. This book focuses on some of the major twenty-first-century forces responsible for this historic reversal, but here is a brief overview of some of the major determinants now driving up both vaccine-preventable diseases and NTDs.

Political Instability. One of the most potent and unanticipated drivers was political instability. Measles was declared eliminated from the Americas in 2016, but in Venezuela, the collapse of the economy interrupted and disabled its health system, allowing measles to come roaring back. However, measles was not the only infection to reemerge. Malaria also became widespread, as did a host of other NTDs transmitted by insects or snails. The so-called Northern Triangle area of El Salvador, Guatemala, and Honduras also suffered because of escalating drug wars and the resulting economic downturns that affected health systems. In the Old World, wars or Islamic State occupation in Syria, Iraq, and Yemen also promoted the return of vaccine-preventable diseases, including measles and polio, while the simultaneous collapse of insect vector control programs promoted an explosion in the number of cases of cutaneous leishmaniasis, a highly disfiguring disease that produces ulcers and permanent and socially stigmatizing scars. A deadly cholera outbreak, one of the largest ever recorded, swept across Yemen. Throughout war-torn Democratic Republic of Congo (DR Congo), Central African Republic, and South Sudan, measles also returned, as did another form of leishmaniasis known as kala-azar, which causes a leukemia-like illness that killed thousands. Ebola caused a new lethal epidemic in DR Congo in 2019, resulting in over 2,000 deaths, and even more fatalities occurred from measles and cholera. The bottom line was that new twenty-first-century wars, conflict, and political unrest were reversing global gains.

Internal Displacement and Human Migrations. Exacerbating war and political instability were the ensuing human migrations. As people fled conflict and political collapse, thousands of refugees poured into neighboring countries and regions to spread disease. Measles became widespread in Brazil, Colombia, and Ecuador, largely reversing the celebrated 2016 achievement of measles elimination in the Western Hemisphere. Populations also began fleeing the drug wars of the Northern Triangle, although this has not yet translated into measles epidemics. However, the disease did reemerge among displaced people in multiple African nations and in the Middle East. The World Health Organization (WHO) issued a global alert on measles and then followed it with a report revealing that approximately 10 million children in 16 countries were not receiving their routine childhood vaccines for measles, pertussis, and tetanus owing to conflict and human displacement [3]. Similarly, leishmaniasis traveled with the Syrian refugees spilling into Jordan, Lebanon, and Turkey, in some cases establishing a foothold in those countries.

Urbanization. Human migrations from conflict and other factors brought people in large numbers into cities in vast and unprecedented numbers. Thousands crowded into urban slums in Caracas (Venezuela), Aleppo (Syria), and Kinshasa (DR Congo). The urban slums of megacities became a dominant theme of a new world order. As populations outstripped infrastructures, diarrheal diseases, including cholera, emerged in the untreated sewage, while respiratory diseases, including measles and other vaccine-preventable infections, emerged in the crowded conditions. Then the coronavirus disease of 2019 (COVID-19) swept across densely populated urban regions of central China, and next Europe and the United States, ultimately causing a destructive pandemic that may trigger a new economic depression. COVID-19 now represents an imminent threat to vulnerable people living in the crowded urban slums of South Asia, the Middle East, Africa, and Latin America.

Anti-science and Nationalism. An equally worrisome social determinant was the new reality of anti-science. The anti-vaccine or anti-vax movement began to take off in the early 2000s, but by 2015, it had become an ugly monster. It emerged as a media empire, with by some accounts more than 400 misinformation websites actively promoted on social media and e-commerce sites. The anti-vax movement weaponized both Facebook and Amazon in their unique ways. Facebook became the major voice of the anti-vaccine movement, while Amazon turned into the greatest promoter of phony, misinformative books and documentaries. Then the movement acquired a political arm that created political action committees (PACs), each working to enact legislation that made it more and more difficult for children to receive access to vaccines. In 2015, a PAC in Texas arose from the Tea Party, a far-right-wing element of the Republican Party [4]. A similar anti-vaccine initiative steeped in the rhetoric of populism arose in Italy. Somehow the anti-vax movement became tied to a new nationalism arising in the United States and Europe. Nationalism itself became a social determinant of disease.

Later in 2017, the leaders of the anti-vax movement began engaging in predatory behaviors to target selected ethnic and religious groups. As vaccination coverage declined among both Somali immigrants in Minnesota and orthodox Jewish communities in New York as a result of specific targeting by the anti-vax movement, terrible measles outbreaks ensued in 2017 and 2019, respectively. Ultimately, measles epidemics became widespread across North America, while Europe suffered a record 80,000 cases in 2018 and 90,000 cases in the first-half of 2019. Despite the great gains from Gavi, measles reestablished a foothold in the United States and Europe. Epidemics also surfaced in Philippines, Samoa, Madagascar, and elsewhere in the developing world, to the point where the WHO declared “vaccine hesitancy” as one of the world’s most pressing global health issues.

Climate Change. The new twenty-first-century determinants of disease also went beyond social ones. Climate change became a dominant force promoting disease. Mosquito-transmitted arbovirus illnesses such as Zika virus infection, chikungunya, and dengue spread across Central and South America and the Caribbean, before entering Texas and Florida in the United States. In southern Europe, West Nile virus infection and other arbovirus illnesses became common; malaria reappeared in Greece and Italy after it had been gone for decades; and schistosomiasis emerged on the island of Corsica. The Middle East experienced unprecedented high temperatures, which often exceeded 50°C, together with periods of severe and prolonged drought, forcing many to abandon their ancient agricultural lands.

However, it was difficult to attribute the appearance or reappearance of these tropical infections unambiguously to climate change. As noted above, in both the Western Hemisphere and southern Europe, human migrations were also widespread, linked to diaspora from Venezuela and the conflict zones of the Middle East and North Africa, respectively. Cities became vast, crowded, and susceptible to infectious disease transmission. If this trend continues, by 2050 the world will be constituted mostly of hot and steamy megacities, each with more than 10 million people. Complicating things further were the sharp economic downturns in many of these cities, especially in Venezuela, Brazil, the Middle East, and parts of southern Europe. COVID-19 furthered these economic declines. In other words, climate change went hand-in-hand with refugee movements, urbanization, and economic collapse. We had no real way to accurately attribute the risk to the individual social and physical determinants that are bringing back global tropical infectious diseases. However, one thing was clear: diseases that we thought we had vanquished through programs of the Millennium Development Goals were now returning.

Science Envoy

My term as US science envoy coincided with the rise in these geopolitical forces and climate change. I focused on evaluating the diseases arising from the conflict zones and then on designing new technologies to prevent these illnesses. As codirector of a nonprofit organization developing vaccines to combat NTDs (Texas Children’s Hospital Center for Vaccine Development), and as someone with expertise in tropical infectious diseases (I am dean of the National School of Tropical Medicine at Baylor College of Medicine), I had a unique perspective on the diseases arising in this part of the world. In time, we redirected some of the activities of our laboratory toward making vaccines to combat some of the leading illnesses. They included vaccines for leishmaniasis, schistosomiasis, and the major coronavirus infections, including Middle East respiratory syndrome (MERS), a highly lethal disease. We were positioned to assist in building capacity for vaccine development and clinical testing across the Middle East. Vaccines are not the only tools needed to fight the emerging and neglected diseases arising out of the conflict zones, but they are perhaps the most efficient and effective at preventing disease. Yet the Middle East and North Africa are highly depleted in terms of vaccine development capacity. At the time I began as US science envoy, these areas possessed few to no vaccine development capabilities. Moreover, the major pharmaceutical vaccine manufacturers had little interest in developing vaccines to combat the neglected and emerging diseases of Syria, Iraq, and Yemen, and at best modest interest in vaccine capacity building. I therefore embarked on a journey in vaccine diplomacy in order to combat the infections arising in the post-2015 new world order, guided by the example of my role model in this endeavor, Dr. Albert Sabin.

2: A Cold War Legacy

I never had the opportunity to meet Dr. Albert Sabin. He passed away in 1993 before I began my association with Sabin Vaccine Institute, a Washington, DC, nonprofit organization that advocates for vaccines and vaccine science. However, for more than 20 years I was connected with the institute. My association began when I was on the Yale faculty (the institute was started by H. R. Shepherd, a businessman based in New Canaan, Connecticut); continued during the 11 years when I was microbiology chair at George Washington University (the institute relocated with me in 2000); and then ended after I had relocated to Houston, Texas.

One of my favorite activities as president of the Sabin Vaccine Institute was visiting Dr. Sabin’s widow, Heloisa. Heloisa lived off New Mexico Avenue in Washington, DC, not far from the campus of American University. She was born in Brazil and worked at Jornal do Brasil, the major newspaper in Rio de Janeiro. By the time Heloisa met Sabin at a reception for him in Brazil, both had been married previously. Shortly after their marriage in 1972, Heloisa moved with him to Israel when he served as president of the renowned Weizmann Institute, before moving to Washington, DC.

Heloisa’s New Mexico Avenue apartment was like a mini-museum to vaccine diplomacy. It featured pictures of Sabin with President Clinton, Pope John Paul II, and Cuba’s Fidel Castro, to name a few. She also had photos of Sabin with Soviet scientists, and on the tables and walls were plaques and remembrances from dozens of countries. Typically, after sitting in her apartment we would go downstairs to have lunch in a restaurant located nearby. We would pass the time talking about Sabin’s life, his fierce determination to vaccinate the world’s children against polio, and the many complexities of working with foreign governments to conduct vaccination campaigns. One story I remember vividly was her account of Sabin’s visit to Brazil in 1980, when he had openly criticized federal and local health officials for their handling of a polio outbreak. Ultimately, his offer to help Brazil mount a national polio campaign was rebuffed, and Sabin returned disappointed to Washington. There were differing accounts of whether the Brazilian officials were too lax or if Sabin was too abrasive; possibly both were true [1]. Sabin was known for his directness, and his unrelenting demand for excellence often made people around him uncomfortable, but Heloisa both adored and revered him. She was petite and beyond charming, and from her pictures I could tell that back in the day, Heloisa and Albert were probably quite the glamorous couple. Heloisa would always refer to him as “my Albert.” On a few occasions, we would visit his gravesite at Arlington National Cemetery, and she would always remind me that one day she would be buried alongside him. Heloisa passed away in 2016 in her late 90s, just before I left the Sabin Vaccine Institute. Currently, the Albert B. Sabin Archives are located at the University of Cincinnati, where he conducted much of his path-breaking work on the oral polio vaccine.

Sabin was a champion of vaccines, but not only because of his important and fundamental research to develop the polio and other vaccines. He was an unofficial polio ambassador, visiting dozens of countries and convincing government leaders at the highest levels about the importance of instituting polio vaccination campaigns. His stature as a vaccine scientist allowed him entry into Cuba during the 1960s and the USSR in the 1950s and 1960s. Those activities in Cuba and the USSR had special meaning for me. Through a program of backchannel diplomacy and scientific collaboration, Sabin worked with Soviet scientists to jointly develop an oral polio vaccine that employed Sabin’s live virus polio strains, which he had first developed at Cincinnati Children’s Hospital. Those virus strains were then produced at an industrial scale in the USSR and tested on millions of Soviet citizens, ultimately leading to the licensure of the vaccine in the early 1960s and the subsequent eradication of polio. These accomplishments are now the gold standard for how scientists of different ideologies can overcome diplomatic tensions or even overt conflict in order to advance science for humanitarian purposes.

Global Health Diplomacy

Each visit with Heloisa reinforced my conviction that vaccine diplomacy could one day hold a special place in modern society. In our post-2015 world, we need vaccine diplomacy more than ever. Global infectious diseases have taken an unexpected turn for the worse. Owing to breakdowns in health infrastructure from war and instability, together with other modern twenty-first-century forces, infectious diseases once thought to be on their way out, or even gone, are now back. The COVID-19 pandemic is testing international relations on an unprecedented level. Solving these and future infectious disease public health crises will require us to integrate the science of tackling global infections with these new social and physical determinants: poverty, war, political instability, human migrations, urbanization, and anti-science. In turn, navigating such troubled waters will require new approaches linking biomedical and social sciences, including political science and foreign policy.

In my two years in the Obama administration as US science envoy, I came to realize that understanding the biomedical science, the vaccinology, was essential but not always sufficient to solve issues related to building vaccine infrastructures across nations. This was especially true in a complicated space like the Middle East, where deep-seated tribal and Sunni-Shia rivalries continuously threw up roadblocks—often in interesting and unexpected ways. It became apparent that building vaccines, expanding vaccine coverage, and tackling NTDs requires integrating new types of knowledge, including skills related to diplomacy. In some ways, this might bear some resemblance to what Sabin achieved in Cuba and the USSR (okay, maybe not Brazil!) in the 1960s, but widening the tent to include both scientists and nonscientists. To achieve this, I suggested a new framework of vaccine diplomacy that connects political science, philosophy, and foreign policy to the most powerful life science technology ever invented—vaccines.

Before describing and defining vaccine diplomacy, I think it is helpful to first provide a broader understanding of how global health in general is linked to international relations and solving disease problems on a large scale [2]. Some might say it began as an early version of quarantine during the 1300s, when laws were implemented to prevent plague originating in Asia Minor from entering Dubrovnik on Croatia’s Adriatic coast—or much later, starting in the 1850s, when international sanitary conferences were held in Europe to prevent cholera, plague, and other pandemic infectious disease threats from spreading [2]. Then, in the early twentieth century, the Office International d’Hygiène Publique was created in Paris, as well as a health organization linked to the League of Nations [3]. In parallel, the nations in the Western Hemisphere also established a Pan American Sanitary Bureau, later named the Pan American Health Organization, which became the regional office of WHO in the Americas. The actual World Health Organization itself was established in the aftermath of World War II, following the formation of the UN. The WHO’s constitution was enacted on April 7, 1948, now designated as World Health Day. Almost twenty years later, the WHO embarked on the eradication of smallpox through a global vaccination campaign.

Global health diplomacy rapidly accelerated after promulgation of the UN’s Millennium Development Goals, first in 2005, with a revised set of International Health Regulations (IHR), and then in 2007, after the ministers of health of seven nations connected global health to foreign policy through an Oslo Ministerial Declaration [2]. IHR, also known as IHR (2005), is an agreement between all WHO member states focused on global health security, especially for the detection and assessment of major public health events and for strengthening disease control efforts at national entry points, such as seaports and airports. A key driver of the IHR (2005) was the 2003 pandemic of severe acute respiratory syndrome (SARS) that resulted in more than 8,000 cases, with roughly 10% mortality [4]. The SARS pandemic also severely affected the economies of Hong Kong and Toronto, Canada, and were a wake-up call for the disruptive power of lethal epidemics. These initiatives were later strengthened in 2019 following the Ebola epidemic in DR Congo and ultimately were called on to respond to COVID-19 the following year. In this context, my former Yale colleague, Ilona Kickbusch, defines global health diplomacy as a system of global governance in health, while Rebecca Katz, a colleague and former student now at Georgetown University, provided an operational definition. She refers to it as a framework to include treaties between nations—such as IHR, or recognized international partnerships with UN international organizations, Gavi, or global partnerships involving the Gates Foundation or other non-state actors [2].

Vaccine Diplomacy

Throughout modern history, vaccines have surpassed all other biotechnologies in terms of their impact on global public health. Because of vaccines, smallpox was eradicated, and polio has been driven to near global elimination, while measles deaths have declined more than 90%, and Haemophilus influenzae type b meningitis is now a disease of the past in the United States and elsewhere.

I define one part of vaccine diplomacy as a subset or specific aspect of global health diplomacy in which large-scale vaccine delivery is employed as a humanitarian intervention, often led by one or more of the UN agencies, most notably Gavi, UNICEF, and WHO, or potentially a nongovernmental development organization [2]. Examples might include emergency cholera or Ebola vaccinations during outbreaks in Africa, measles vaccination campaigns linked to the Venezuelan diaspora in Brazil or Colombia, or polio eradication campaigns in the conflict areas of Afghanistan, Pakistan, or the Middle East. Other aspects of vaccine diplomacy relate to vaccine access during pandemics, such as efforts to ensure equitable delivery of a vaccine to combat influenza, especially during an epidemic or even a pandemic situation.

Another critical element of vaccine diplomacy includes the development or refinement of new vaccines achieved jointly between scientists of at least two nations. Rather than a UN agency or nongovernmental development organization, the actual scientists lead both the vaccine science and diplomacy [2]. It is especially relevant that scientists from nations in opposition or even outright conflict can work in research organizations, or that they are able to work together and engage in collaborations under conditions of political instability or stress. Under this definition, vaccine diplomacy reached its full expression during a 20-year period of the Cold War between the United States and Soviet Union that began around the time of the Sputnik satellite launch and mostly ended in 1977 with the eradication of smallpox [5]. In my role as US science envoy, I worked to resurrect this vaccine science diplomacy while collaborating with scientists from Muslim-majority countries of the Middle East and North Africa [6].

Do vaccines really deserve their own designation for a special type of diplomacy? Yes, I believe so, especially when we consider that between the past century and this one vaccines have saved hundreds of millions of lives [2]. In this sense, the technology of vaccines and their widespread delivery represent our most potent counterforce to war and political instability in modern times. Vaccines represent not only life-saving technologies and unparalleled instruments for reducing human suffering, but they also serve as potent vehicles for promoting international peace and prosperity. They are humankind’s single greatest invention.

A Brief History of Vaccine Diplomacy

The history of vaccine diplomacy traces an interesting narrative parallel to the history of the vaccines themselves. It started with the British physician Edward Jenner, who in the late 1700s developed the first and original smallpox vaccine. Indeed the word vacca, Latin for “cow,” refers to the fact that the attenuated virus used in the vaccine derived from cows infected with the cowpox virus. However, a more recent analysis questions the true origins of the virus that Jenner actually used, which might have been horse pox, or even another virus entirely, designated simply as “vaccinia” [7]. Jenner’s smallpox vaccine had an immediate impact on public health in England, and it was transported across the Atlantic Ocean to America, where Thomas Jefferson himself conducted vaccine trials in and around Virginia. When he commissioned Meriwether Lewis and William Clark for their expedition a year after the Louisiana Purchase in 1803, Jefferson either encouraged or arranged for them to carry the vaccine into the frontier [2]. Back then, smallpox was devastating Native American populations in the Northern Plains, so the vaccine was potentially a gesture of peace or goodwill. Unfortunately, some historians report that the vaccine preparation degraded to a point where it was never actually used.

In Europe, both England and France celebrated and honored Jenner’s achievements despite increasing hostilities between the two nations. In the period following the French Revolution and after Napoleon became military dictator of France in 1799, Britain had become increasingly concerned about his armies expanding across Europe and his efforts to stop European nations from trading with England. Finally, in 1803, Britain declared war on France, beginning with a naval blockade of the country. Historic battles at Austerlitz and Trafalgar ensued. However, Jenner’s reputation and veneration as the first vaccine scientist had grown to such a point that he was asked to write letters (and possibly engage in other activities) mediating the releases or exchanges of prisoners [2]. For example, in a letter to the French National Institute of Health, he asserted that “the sciences are never at war.” In turn, Napoleon (or some say Empress Josephine) declared, “Jenner—we can’t refuse that man anything” [2]. Ultimately, the Napoleonic wars ended with Napoleon’s defeat at Waterloo, the last time France and England went to war.

These vignettes highlight a future paradigm that subsequently held for the next 200 years—namely, (1) the immediate recognition of the impact of a vaccine as a highly valued technology, and (2) the enormous scientific and professional stature of vaccinologists—vaccine scientists and vaccine developers. That is, until the modern-day anti-vaccine movement began to target us beginning in the early 2000s. An elusive third element, although one not as straightforward and tangible, also attaches to vaccines: the potential for vaccines to both prevent diseases arising out of conflict or twenty-first-century forces, and in some cases, to directly address the actual social determinants. For example, Jenner’s vaccine was itself employed as an instrument of peace during the Napoleonic wars, creating a novel thread through modern history. When another renowned Frenchman, Louis Pasteur, developed the next few vaccines in the mid-1800s, he also used his stature to launch a network of Pasteur Institutes across the Francophone world, including North Africa and Southeast Asia, which initially focused on reproducing Pasteur’s method to prepare and deliver the first rabies vaccine. Echoing Jenner’s comments, Pasteur in an 1888 speech at the founding of the Institut Pasteur in Paris remarked that “science has no country, because knowledge belongs to humanity and is the torch which illuminates the world” [2].

The Cold War was a 45-year period of political hostilities between the United States and the Union of Soviet Socialist Republics that began after World War II and divided much of the globe into two major spheres of influence. Ironically, it became the signature period that generated the fullest expression of vaccine diplomacy. Two enemies put aside their animosities in order to collaborate on the development and testing of the oral polio vaccine, which is now leading to its global elimination or eradication. This is an extraordinary story that few people outside the vaccine world know about. The 1957 launch of the Sputnik satellite was a key moment in American history, when the nation feared falling behind the Soviets in mastery of both space and missile technology. It became a dark chapter in US history when—following on the heels of the “red scare” that resulted from the Soviet annexation of eastern Europe, the Berlin blockade, and our proxy war with China in Korea—we became vigilant, even hyper-vigilant, for any signs of Communist presence on our soil.

One might argue that this was not an ideal time to begin a US-Soviet scientific collaboration on vaccines, but that is more or less what occurred. It turned out that the fear of polio exceeded the threat of Communism. The 1952 polio epidemic in America was the worst on record. It killed more than 3,000 people and caused partial or complete paralytic disease in more than 20,000. Increasingly during the 1950s, school-age children and adolescents were polio victims. Parents in cities across America lived in terror of summer polio epidemics.

Polio also raged in the USSR. Between 1954 and 1959, polio was present in all of the Soviet republics and increasing in incidence yearly, with the highest rates in the Baltics [8]. Polio outbreaks also occurred in Moscow and Minsk [9]. In response, Soviet scientists in 1955 established a Poliomyelitis Research Institute in Moscow and appointed Dr. Mikhail Chumakov to head experimental vaccine development. Another key individual was Dr. Anatoly Smorodintsev, the head of the virology department of the Institute of Experimental Medicine of the USSR Academy of Medical Science [8]. With the agreement of both governments, Chumakov and Smorodintsev traveled to the United States in 1956 to visit with Albert Sabin, who had developed a polio vaccine containing three different live, attenuated poliovirus strains administered by mouth.

Sabin was eager to cooperate with the Soviet scientists because by this time the injectable polio vaccine invented by Dr. Jonas Salk, composed of three virus strains that have been inactivated or killed with formalin, was already licensed and widely used in the United States. So not only was there little appetite to replace it with the Sabin vaccine, but there were insufficient numbers of unvaccinated American children available for testing with the oral version [9]. While Dr. Sabin was able to immunize his own family and small numbers of incarcerated young adults at a federal prison located not too far from his Cincinnati Children’s Hospital laboratory, the number of vaccinated volunteers was far too small for his oral vaccine to achieve product licensure in the United States [9].

As an aside, I will mention that I was privileged to meet with Jonas Salk in 1995. Our meeting was held in his office at the Salk Institute, considered by many to be one of the most visually striking research institutes ever built. It was designed by the famed architect Louis Kahn and overlooks a beach on the coast of La Jolla, California, just north of San Diego. At sunset, the light shines through a gap between its two major buildings, providing an unforgettable effect. At that time, I was an assistant professor at Yale, just a few years into beginning my own vaccine laboratory. Dr. Salk was one of the most gracious and welcoming senior scientists of stature I had ever met. He even agreed to help me further the development of our hookworm vaccine. We spent more than an hour together, during which he proudly showed me the paintings he displayed in his office by his wife, Françoise Gilot (and former partner of Pablo Picasso). I remember the exhilaration after leaving our meeting, believing that Dr. Salk could become an important mentor. I was devastated when just a month later my wife, Ann, phoned me at a meeting in the United Kingdom to tell me that he had passed.

To return to the story: Because the Salk vaccine required an injection, there was still a global need for a different type of polio vaccine that could be administered without the use of a needle and therefore trained medical personnel. This was especially important in developing countries of Africa, Asia, and Latin America, where qualified staff were lacking and health systems were depleted. For poor nations in Africa, Asia, and the Americas, the Sabin vaccine checked a number of boxes. It contained live polioviruses that were weakened or “attenuated” to a point where they can no longer cause disease. The advantage is that the Sabin poliovirus vaccine strains can be given orally because they stimulate a child’s immune response by replicating in the gastrointestinal tract. If it worked, a large group of children in a village or town could be lined up and given the Sabin vaccine via liquid drops, or even drops placed on a sugar cube.

Following the 1956 visit by Russian scientists to the United States, our State Department allowed Sabin to make a reciprocal visit in the summer of that year [9], launching an extraordinary international collaboration in which Sabin’s live polio strains were scaled up for production in the USSR and first tested in Soviet children. Sabin provided sufficient amounts of the vaccine to begin immunizing children in both the USSR and Czechoslovakia, as well as seed lots so that the Soviets, under the direction of Dr. Chumakov, could scale up the virus themselves. According to William Swanson, a freelance journalist based in Minneapolis who wrote about this period for Scientific American, Chumakov had to use his Politburo connections to go over the head of the Russian minister of health, who would not authorize clinical testing of the Sabin vaccine [9]. Chumakov was a courageous man, who always put science and the health of the USSR’s children above politics. His son Dr. Konstantin Chumakov, himself an important vaccine scientist at the US Food and Drug Administration, is a colleague who shared with me fond remembrances of his father, who was a great defender of science during a very difficult period both before and immediately after the death of Stalin. Dr. Mikhail Chumakov died just a few years after Sabin passed away in 1993.

Ultimately, toward the end of 1959, the Russians had successfully prepared 10 million doses of the vaccine derived from Sabin’s live polio strains. The Soviets vaccinated millions of children. In 1991, Dorothy Horstmann, one of the founding professors of virology at Yale University (and a former mentor who recruited me to Yale after my residency at the Children’s Service of the Massachusetts General Hospital) wrote about her experience of providing an independent assessment of the subsequent polio clinical trials that began in 1959. In anticipation of those trials, the WHO asked her to assess in detail over a sixweek period the quality control of the polio laboratories and whether the Soviets implemented adequate steps to ensure the safety of the vaccine [8].

She also reported on Chumakov’s travels across the USSR to meet with groups of physicians in order to organize the vaccination campaign. He went on local TV and radio to ask for community cooperation and worked with local newspapers to explain the importance of the vaccination drive [8]. Detailed surveillance surveys followed, which included home visits by healthcare providers to assess whether there were any harmful effects of the vaccine. In the case of a campaign launched in Tashkent, Uzbekistan, during an actual polio epidemic, epidemiologists went to individual homes to determine the public health impact of the vaccine. An estimated 10–15 million Russian children received the oral polio vaccine developed jointly by Sabin on the US side and Chumakov and colleagues on the Soviet side. Ultimately, almost all Soviet citizens under the age of 20, approximately 100 million individuals, received the vaccine. According to Dr. Horstmann, “Its positive assessment contributed to a rebirth of interest in the oral vaccine and paved the way for large field trials in the United States, leading to licensure of oral vaccine in 1961–62” [8].

As a result of global access to the oral polio vaccine, by 2019 the disease has been eliminated from all but three countries—Nigeria, Afghanistan, and Pakistan —where local hostilities and conflict have interfered with efforts by UN agencies and community health workers to reach all of the areas that require vaccine access.

Downstream, the Sabin vaccine will likely be gradually replaced by the Salk vaccine. While it is clearly beneficial to administer an oral vaccine, a distinct disadvantage of the Sabin vaccine is that it is composed of live virus strains, which can undergo mutation. This means that vaccinated children can—although rarely—shed a mutated version of the virus into the community that produces complications similar to the wild-type poliovirus, including paralysis. Therefore, to truly eliminate global polio, it is believed that follow-up vaccinations with the Salk killed vaccine may be required, and the Salk vaccine is gradually being adopted in most countries. I find it ironic that both the Sabin and Salk vaccines were ultimately required to eradicate global polio. The irony stems from the fact that they were bitter rivals. In my Baylor College of Medicine office, I have a reproduction of a photo of Drs. Sabin and Salk seated next to each other at a conference, but what makes it special is the onlooker seated behind them with an expression of astonishment.

Health as a Bridge to Peace

Joint international development and testing of an oral polio vaccine proved to be a powerful force in overcoming Cold War ideologies. It also became one of the most important and successful biotechnologies ever invented—one that is leading to global polio elimination. Now the WHO has taken the humanitarian dimension of the oral polio vaccine a step higher through its Health as a Bridge for Peace program and its Humanitarian Cease-Fires Project [10]. The project brokers cease-fires in war-torn areas of Afghanistan, Iraq, South Sudan, and elsewhere in order to vaccinate children against polio. A product of the Cold War, to this day the polio vaccine remains a potent weapon for waging peace and eliminating disease.