Father of polio vaccine: ‘Opportunities always come from dead ends’

Polio used to be a medical emergency with no specific prevention or treatment. In 1952, the US recorded more than 57,000 cases, a record high. The virus can cause spinal paralysis and respiratory paralysis. Many patients must lie in large metal ventilators, called “iron lungs”, to maintain life.

Images of children lying motionless in iron lungs or wearing leg braces became haunting symbols of polio. Although less than 1% of infections lead to paralysis, the scale of the outbreaks means many children are still in serious condition. Some people have to stay on a ventilator for days, months or years. For many families, summer is a scary time because polio outbreaks often appear during this period.

The disease doesn’t just affect young children. Franklin D. Roosevelt, later President of the United States, fell ill in 1921 at the age of 39 and was paralyzed from the waist down. After entering the White House, he turned the fight against polio into a personal goal. In 1938, Roosevelt founded the March of Dimes, an organization that raised funds based on small contributions from the masses, instead of relying solely on large donations.

By the late 1940s, scientists determined that the polio virus entered the blood through the intestinal tract. At the same time, two prominent vaccine development directions were formed. Dr. Albert Sabin pursued a live attenuated virus vaccine. Jonas Salk, a researcher at the Pittsburgh School of Medicine, chose a vaccine that uses a completely inactivated virus.

Salk had the advantage thanks to the support of the March of Dimes. This funding helped him set up a laboratory right in a hospital treating polio patients in Pittsburgh. The research team used inactivated polio virus to create a vaccine. The big problem is to prove that this product can stimulate the body to create antibodies against the virus.

In an interview with BBC On June 12, 1982, Salk said the vaccine development process came from iterative efforts. Many unexpected situations appeared during work, forcing the research team to adjust direction and take advantage of new results.

When asked whether the research process encountered “dead ends”, Salk replied: “For me, dead ends are always opportunities.” He believes that the unforeseen is often a signal for scientists to seek another path.

According to Salk, the vaccine breakthrough came quite quickly from his perspective, but the achievement was based on decades of previous research. He began his work in 1948, when the polio virus had just been successfully cultured in tissue. Laboratory tools are available and three main types of poliovirus have been identified.

By the period 1951-1952, the research team was able to test injecting children. In 1953, the initial data became clearer. In 1954, large-scale testing was carried out. A year later, the vaccine was announced for widespread use.

Before entering the big trial, Salk vaccinated himself, his wife, three sons and those who worked with him in the laboratory. His son, Peter Salk, later recalled that his father brought home needles and syringes, boiled them to sterilize them in a kitchen pot, and then injected his children with experimental vaccines. For Salk, it was something he did when he was confident enough in the safety of the vaccine.

To confirm that the vaccine is effective, a much larger trial is needed. In April 1954, one of the largest medical trials of that time began in the United States. More than 50,000 teachers participated in assisting with vaccinations and monitoring nearly two million children. The results were cross-checked for a year before publication.

On April 12, 1955, exactly 10 years after Roosevelt’s death, the results were announced. An American reporter described this as one of the brightest news in human history. Church bells rang in many places, factory whistles were pulled, and many people cried with relief. For American families, this announcement ended years of living in fear of polio.

The number of recorded polio cases in the United States plummeted from about 60,000 to 2,000 within a year after Salk’s vaccine was introduced. Within a decade, polio was nearly eliminated in the United States.

This success made Salk internationally famous overnight. However, he sees the public reaction as primarily an appeasement of fear, rather than personal glorification. To avoid being drawn away from research, he went on to establish the Salk Institute, an independent non-profit research center in California, with the goal of attracting top scientists.

After Salk’s vaccine, Albert Sabin’s oral polio vaccine was also widely used. Oral formulations are suitable for mass vaccination campaigns because they are easier to deploy than injections. Both vaccines make important contributions to polio control efforts around the world.

The notable common point is that neither Salk nor Sabin registered vaccine patents for financial gain. When asked who owns the patent for the polio vaccine, Salk replied: “I think it’s the people. There are no patents. Can the sun be patented?” Sabin also sees his vaccine as a gift for children around the world.

From a disease that haunts society to a vaccine turning point, Jonas Salk’s story shows that science does not only advance with favorable results. Sometimes, it is the “dead ends” in research that open up opportunities to find another path.