The polio vaccine debate
All drugs and immunizations have side effects and risks. Before taking a drug that kills metastatic cancer cells a patient must accept the often considerable side effects and potential harm.
Immunizations protect individuals and widespread immunizations prevent potential mass outbreaks. For new vaccines the FDA usually requires studies where one group gets the vaccine, the second doesn’t, and both groups are exposed to a disease. In 2022 the agency allowed the current Sanofi polio vaccine to be marketed without such a test. Given what we know about the vaccine and the disease, they felt it was wrong to allow a large group of unvaccinated people to be infected by the polio virus.
Polio is a viral disease. “It once killed or paralyzed more than half a million people around the world each year. “It’s caused by an enterovirus, a sub-microscopic organism that is highly contagious. Before we had an effective vaccine the virus transiently inhabited the GI tract of most humans, and most of the infections it caused were mild. One in 4 infected people had flu-like symptoms that lasted 2 to 5 days and fewer than 1% had weakness or paralysis in their arms and/or legs. When it occurred the weakness was usually asymmetrical and predominantly affected a person’s lower limbs. Less than one percent of those infected developed the severe acute paralytic form of the disease. The severe condition often progressed for up to one week and caused permanent weakness in two-thirds of the afflicted people. It was labeled paralytic polio and it was said to have a mortality rate that ranges between 5 and 15%.
There are three poliovirus serotypes and immunity to one serotype does not produce significant immunity to the other serotypes.
There has not been a case of wild polio that was acquired in the United States since 1979. The last imported case of wild polio was in 1993. Worldwide--“Wild poliovirus cases have decreased by over 99% since 1988, from an estimated 350 000 cases in more than 125 endemic countries then, to just two endemic countries.”
In the late 1930s and 1940s most Americans knew of and feared polio, in large part because of what it did to the nation’s president, Franklin Roosevelt. Roosevelt led the nation for 15 years and brought about great changes. He helped the nation recover from the great depression and guided the country through the Second World War. He passed a “tax the rich” act that “raised the top income tax rate to 75% for those earning over $1 million per year” and social security a financial program that helped the elderly survive.
A dozen years before he became the nation’s 32nd president. Roosevelt developed a severe illness that paralyzed him from the waist down. When he recovered, his ability to walk was severely compromised. The illness began “On August 9, 1921. That day 39-years old Franklin joined his family at their vacation home at Campobello, a Canadian island off the coast of Maine. He came down with an illness characterized by fevers, ascending paralysis, and facial paralysis. His illness was life-threatening but he survived. When he got “well” he was permanently paralyzed from the waist down.
Years later, when he was president “his public appearances were carefully choreographed to avoid the press covering his arrival and departure, which would have shown him getting into or out of a vehicle or train. In private he used a wheelchair, but was careful not to be seen using it in public, although he sometimes appeared on crutches. He usually appeared in public standing upright, supported on one side by an aide or one of his sons. For major speaking occasions, an especially solid lectern was placed on the stage so that he could support himself on it; In 1938, Roosevelt founded the national foundation for infantile paralysis and that lead to the development of polio vaccines.”
In the 1800s powerful microscopes were created and mankind learned that many of the illnesses that afflict us are caused by tiny tiny bacteria, and by even tinier creatures that were smaller than the wave length of light. In 1931 German scientists Ernst Ruska and Max Knoll, developed the electron microscope, a tool that allowed scientists to visualize the viruses that afflict us. These super-small invaders are dormant in the wild but when they enter a cell they can take over and multiply wildly.
In 1949, John Enders and others successfully grew polio and other viruses in tissue. He later won the Nobel Prize. In the 1950s, Jonas Salk developed a vaccine for polio.
The son and grandson of immigrants Salk was born in New York, graduated from medical school in 1939, and became a research bacteriologist. In 1941 he moved to Ann Arbor Michigan and began assisting a forty-one–year-old influenza researcher named Thomas Francis. The son of a steelworker, Francis had spent the previous decade studying the influenza virus. As one of his helpers, Salk learned how to create inactivated vaccines and how to prove they worked.
In 1947, at age thirty-three, Salk was given a laboratory at the University of Pittsburgh that was funded by the March of Dimes, Roosevelt’s charity.
Salk grew the poliovirus in monkey kidney tissue cultures and used formalin to inactivate it. The vaccine was then given to 2 million schoolchildren as part of a placebo- controlled trial. In April /1955, the nation learned that it was safe and effective and Salk became an instant icon. His celebrity status troubled his medical colleagues and affected his marriage of twenty-eight years. He ended up divorcing his first wife and married Francoise Gilot, a woman who had been the “longtime lover of Pablo Picasso.”
Six pharmaceutical companies were licensed to produce the vaccine, and Salk did not profit from sharing the formulation or production processes.
In a 1955 interview with famed journalist Edward R. Murrow Salk was asked “who owns the patent on this vaccine,” Salk replied, “the people.” Then he paused for a moment: “Could you patent the sun?” Some claim the University of Pittsburgh lawyers had already concluded the product wasn’t patent-able.
The other developer of a polio vaccine was born in Poland and was fifteen when he and his parents came to the United States. Albert Bruce Sabin eventually went to medical school, graduating in 1931. While studying polio at the Children’s Hospital Research Foundation in Cincinnati, Ohio, Sabin discovered that polio viruses lived in the small intestines before they attacked nerves. During the Second World War, Sabin served in the army and developed at least one vaccine. When the conflict ended, he returned to Ohio and resumed his research. By growing polio virus in monkey kidney and testicular cells he created a polio mutant that flourished in the intestines, didn’t cause disease, and prevented infections with the wild virus. He then cultivated and tested a few strains of his virus and gave doses to his family and to prisoners from a nearby penitentiary. The viruses seemed safe and they became the basis of an oral vaccine. At the time, the U.S. wasn’t interested. The country was committed to Salk and wouldn’t allow Sabin to test, produce, or administer his creation.
In 1955, the Russians founded a Polio Research Institute in Moscow. In 1956, its head virologist, Mikhail Chumakov, visited Salk in Pitts- burgh and Sabin in Cincinnati. Sabin spoke a little Russian, Chumakov a little English, and they became friends. The following year, Sabin spent a month giving lectures in Russia, meeting with researchers, and promoting his vaccine. When he returned home, the Salk vaccine was being widely used and an American researcher advised Sabin to toss his vaccine “in the sewer.” In 1958, Chumakov tested a vaccine made with Sabin’s seed virus on twenty thousand Russian children. It was safe, easy to administer, and effective. Chumakov got permission from the public health chief of the Politburo and distributed the oral vaccine to more than 15 million Soviets. He later treated 23 million children in East Germany, Czechoslovakia, Hungary, Romania, and Bulgaria. An expert sent by the WHO agreed the vaccine seemed to be working but “definitive results would take time.” Sabin refused to patent the oral vaccine, and it is currently widely used in the poorer countries of the world.
On April 26, 1955, shortly after it was licensed, the nation learned the Salk vaccine was making some kids sick and was causing paralysis and a few deaths. Half of the 760,000 doses made by Cutter in Berkeley, California, were recalled. In the end, “forty thousand kids who received the vaccine developed polio, two hundred had at least partial paralysis and ten died.” The formaldehyde in the vats had failed to completely inactivate the virus.
The vaccine was pulled from the market, the Sabin vaccine became available in the U.S. and it was used in this country between 1962 and 1969. Over time we learned that the oral virus occasionally mutates in a person’s intestine and causes polio and paralysis.
In 1987, a new, potent injectable polio vaccine was introduced. The Salk polio vaccine was tested in a large, double-blind, placebo-controlled trial in 1954. The current polio vaccine, manufactured by Sanofi, was not tested against a placebo because scientists and doctors generally agree that withholding a lifesaving vaccine would be unethical. It was safer than the original Salk product and it became the only vaccine used in the U.S. and Europe. In the rest of the world, “more than 10 billion doses of oral vaccine were given to 3 billion kids during the last twenty years.” The World Health Organization thinks they have prevented 13 million cases of polio, but caused 8 bad cases of the disease each year. In 1999, federal regulators in the U.S. decided to replace it with the current inject able vaccine. They believed it was safer.
During the last half of the 20th century, states started requiring kids who attended public schools to be immunized. Most families complied and the rest were usually shielded by “herd” immunity. If all or most kids in a community are protected, those who have not been immunized are unlikely to be exposed to the disease. These shots sometimes caused fever and joint aches, and one in a million kids developed encephalitis, a serious brain inflammation. The complications led to lawsuits and pharma wanted to stop producing vaccines. In response, Congress passed the 1986 National Childhood Vaccine Injury Act, and the government started compensating the families of people who were harmed.
The oral polio vaccine (OPV) is still used in more than 140 countries to immunize children. However, the United States has exclusively used the inactivated polio vaccine (IPV) since 2000.
The primary disadvantage of OPV derives from its inherent nature. As an attenuated but active virus, it can induce vaccine-associated paralytic poliomyelitis (VAPP) in approximately one individual per every 2.7 million doses administered. The live virus can circulate in under-vaccinated populations (termed either variant poliovirus or circulating vaccine-derived poliovirus, cVDPV) and over time can revert to a neuro-virulent form causing paralytic polio. This genetic reversal of the pathogen to a virulent form takes a considerable time and does not affect the person who was originally vaccinated. With wild polio cases at record lows, 2017 was the first year where more cases of vaccine derived polio virus were recorded than the wild polio virus disease.
Until recent times, a trivalent OPV containing all three virus strains was used, and had nearly eradicated polio infection worldwide With the complete eradication of wild polio virus type 2 this was phased out in 2016 and replaced with bivalent vaccine containing just types 1 and 3, supplemented with monovalent type 2 OPV in regions where vaccine derived polio virus type 2 was known to circulate, the switch to the bivalent vaccine and associated missing immunity against type 2 strains, among other factors, led to outbreaks of circulating vaccine-derived polio virus type 2, which increased from 2 cases in 2016 to 1037 cases in 2020.
Novel OPV2 vaccine (nOPV2) which has been genetically modified to reduce the likelihood of disease-causing activating mutations was granted emergency licensing in 2021, and subsequently full licensure in December 2023.This has greater genetic stability than the traditional oral vaccine and experts believe it is less likely to revert to a virulent form. Genetically stabilized vaccines targeting polio virus types 1 and 3 are in development, with the intention that these will eventually completely replace the Sabin vaccines.
https://www.ecdc.europa.eu/en/poliomyelitis/facts
https://www.cdc.gov/polio/hcp/clinical-overview/index.html
https://www.who.int/news-room/fact-sheets/detail/poliomyelitis
https://en.wikipedia.org/wiki/Paralytic_illnessof_Franklin_D._Roosevelt
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