Albert B. Sabin

Albert B. Sabin: The Vaccine You Swallowed

Before he would give his polio vaccine to anybody else, Albert Sabin and his research associates drank the live weakened virus themselves. What emerged from that laboratory was a few drops administered by mouth rather than a needle in the arm — a vaccine cheap enough and simple enough to be carried into villages with no clinic and no refrigeration. Getting there required Sabin to demonstrate that the entire field was wrong about how polio entered the human body, and then to run his decisive trial in the Soviet Union, because he could not get one in the United States.

Białystok to New York

Sabin was born on 26 August 1906 in Białystok, then part of the Russian Empire and now in Poland. In 1921 his family emigrated to the United States to escape the persecution of Jews, and he became an American citizen in 1930. He took his M.D. at New York University in 1931 and began working on polio immediately, training afterwards at Bellevue Hospital in New York and at the Lister Institute of Preventive Medicine in London.

The Wrong Route

Sabin joined the University of Cincinnati College of Medicine in 1939 as associate professor of pediatrics, and it was there that he made the discovery on which everything else rests. The prevailing theory held that poliovirus entered through the nose and the respiratory system and travelled to the nerves. Working from autopsy studies, Sabin disproved it. The virus, he showed, first attacks the intestinal tract, and only afterwards moves to nerve tissue.

This was not a detail. If polio is fundamentally an infection of the gut, then the logical place to meet it is the gut — which means a vaccine that can be swallowed, and which produces immunity precisely where the virus lands.

War Work

When the Second World War began, Sabin joined the Virus Committee of the U.S. Army Epidemiological Board and served in Europe, Africa, the Middle East and the Pacific. It was an education in field epidemiology under impossible conditions, and it was productive: during those assignments he developed vaccines against encephalitis, sand-fly fever and dengue fever. The experience of immunising soldiers in places without infrastructure shaped what he built next.

Three Weakened Strains

After the war he returned to polio. His conviction, against Jonas Salk's, was that only a living virus could guarantee immunity over an extended period; Salk maintained that a killed-virus vaccine was safer, because a vaccine containing no live virus could not conceivably cause the disease. By 1957 Sabin had isolated weakened strains of all three types of poliovirus capable of provoking antibodies without producing illness. He and his colleagues tested them on themselves first. Trials ran from 1957 to 1959.

The Soviet Trial

By then Salk's injected vaccine was already in successful use across the United States, and Sabin could not secure backing for a large controlled field trial at home. So he went abroad, persuading the Soviet Union to run one; further trials took place in Czechoslovakia. They succeeded in 1960, demonstrating the oral vaccine's effectiveness on a scale nothing in America could have matched. The U.S. Public Health Service approved the vaccine in 1961, and it became commercially available the same year.

It then did what Sabin had designed it to do. Because it was so easy to give — no syringes, no trained injectors, no cold chain of the same severity — the oral vaccine replaced Salk's injectable version across much of the world, driving mass immunisation campaigns through Central and South America and becoming the global standard for polio immunisation.

Later Years

Sabin became professor emeritus at Cincinnati in 1971, served as president of the Weizmann Institute of Science from 1970 to 1972, and in 1974 became a full-time consultant to the U.S. National Cancer Institute while also holding a research professorship at the Medical University of South Carolina until 1982. He retired from full-time work in 1986 but went on lecturing and consulting, campaigning for international cooperation on disease eradication. He died on 3 March 1993 in Washington, D.C., aged eighty-six, and is buried at Arlington National Cemetery.

Why Albert Is Called a Genius

Sabin's claim rests on two linked acts of judgement, the first analytical and the second strategic. The analytical one was refusing the consensus about how poliovirus reaches its victims. Everyone knew it entered through the respiratory tract; Sabin looked at the pathology and established that the infection begins in the digestive system. Overturning a settled belief about a disease that was terrifying an entire continent, on evidence, is the harder half of science.

The strategic act followed from it. Having located the infection in the gut, he pursued a live attenuated vaccine that could be swallowed — betting on durable immunity and, critically, on deliverability. A vaccine that requires a needle and a trained hand is a vaccine for rich countries. A vaccine given as drops in the mouth can be taken anywhere by anyone, and that is why polio was pushed out of most of the world rather than merely out of North America. His willingness to drink the virus himself, and to take his trial to a Cold War adversary when his own country would not fund it, describes a particular kind of nerve.

The counter-case is substantial and should not be waved away. Salk got a working vaccine into American arms first, and lives were saved in the interval. More damagingly, Sabin was wrong about the safety question that divided them: a live-virus vaccine carries a slight but genuine risk of causing paralysis, and by 1999 a federal advisory panel recommended the United States return to Salk's killed-virus vaccine for exactly that reason, a recommendation reconfirmed in 2009. The decisive trials were run by Soviet colleagues on Soviet populations. And Sabin's later research, including his cancer work, produced nothing approaching the same significance. His genius was real and specific; it was not infallible.

Legacy

The drops on a sugar cube are among the most consequential objects of the twentieth century. Polio, which crippled children by the hundred thousand within living memory, has been driven to the edge of extinction, and the instrument that did most of the work in the poorest parts of the world was Sabin's. The eventual return to Salk's vaccine in wealthy countries is not a refutation but a sign of victory: a nation only worries about a one-in-millions vaccine risk once the disease itself has stopped arriving.

Achievements

• Bavarian Order of Merit
• National Medal of Science — 1970
• Lasker-DeBakey Clinical Medical Research Award — 1965
• Presidential Medal of Freedom — 1986
• Notable work: polio vaccine
• Affiliated with University of South Carolina and University of Cincinnati
• Educated at New York University and Grossman School of Medicine
• Worked as virologist, university teacher and inventor