The Polio Vaccine Is 70 Years Old: From A Historic Breakthrough to Modern Doubts About Some Vaccines
By Sandor Szabo, MD, PhD. MPH, DSc (h.c.), Professor and Dean, School of Medicine
“Seventy years ago, on April 12, 1955, a scientific breakthrough changed the course of public health and inspired hope worldwide. The polio vaccine developed by Jonas Salk and his colleagues was officially declared “safe, effective, and potent”—a moment heralded as a triumph of medicine over one of the most feared diseases of the 20th century.” (1).
This and the subsequent quotes are from the 2025 Spring issue of Inside Salk, a magazine established by Dr. Salk (Fig. 1) following the huge success of the polio vaccine he discovered and developed.
“The most successful public health interventions are often overlooked or underappreciated—we take them for granted because you don’t see what’s not there,” says Salk President Gerald Joyce. “The near-total absence of polio in the US over the past several decades makes it difficult for most of us to understand just how terrible it was and too easy to devalue the heroic efforts that went into eradicating it.” (1)
Poliomyelitis was a dreadful disease that reached epidemic proportions in the early 1950s in the USA. This viral infection affected the spinal cord, which innervates and moves the muscles that expand the lungs. This anato-physiologic unit is crucial for normal breathing; hence, infected children remained mentally and intellectually normal, but they gradually lost breathing function. If they were placed in mechanical breathing machines (“iron lungs”), they had a chance for survival (Fig. 2). If the leg muscles were paralyzed, they could not walk. (Fig. 3)
Since there were no effective antiviral drugs at that time, the race was on to develop a vaccine to PREVENT the disease—yet again proving the basic principle of public health: ‘prevention is best and least expensive treatment’. (If this sounds familiar to you because of our recent experience with the COVID-19 pandemic, it is not surprising.) Thus, the polio vaccine development programs were launched about 75 years ago by two laboratories, led by Drs. Jonas Salk and Bruce Sabin, which resulted in successful and safe vaccines. ‘The main difference is that the Salk vaccine uses a killed virus and is delivered via injection, while the Sabin vaccine uses a live, weakened (attenuated) virus and is administered orally. The Sabin vaccine provided longer-lasting immunity and was easier for mass vaccination campaigns, leading to its widespread adoption, but it also carried a rare risk of causing paralysis from the weakened virus itself.’ ( Difference between Salk and Sabin polio+vaccines )
Hence, it is not surprising that the killed-virus vaccine of Dr. Salk became more popular (due to the lack of fear of getting infected from the attenuated virus) and children in 1954 were ready to roll up their sleeves to receive the vaccine injection (Fig. 4).
After these medical breakthroughs and public health successes with vaccinations against polio and COVID-19, it is astonishing & incomprehensible to most of us with a public health background (e.g., MPH) when we hear and read articles and opinions spreading false information about the safety of modern vaccines. This is especially alarming if it comes from high-ranking government officials! Even worse when these false theories make links to the rising incidence of completely unrelated disorders, like the false claim linking the rise of autism to measles vaccinations. If we objectively review the history of some diseases and their diagnostic designations, we learn that the incidence of autism started to rise when this narrowly defined mental health disorder was widely expanded to include many other forms of mild or severe mental disorders in children under the new diagnostic term ” autism spectrum disorder” (ASD). Namely, in 1980, the Diagnostic and Statistical Manual of Mental Disorders (DSM-III) officially recognized autism as a separate diagnostic category. The DSM-IV, released in 1994, further expanded the diagnosis to include a range of conditions known as “autism spectrum disorders.” In 2013, the DSM-5 consolidated these diagnoses into a single category called ASD. This change reflected the growing understanding that autism is a spectrum of conditions with varying severity and symptoms ( When did autism spectrum disorder become a diagnosis ).
And we have just started to see the dangerous effects of these false theories, e.g., a few months ago, Florida became the first state to eliminate mandatory vaccination against most frequent infectious diseases in children and several southern states are considering similar recommendations, i.e., essentially leaving to parents to decide what vaccinations, if any, they prefer for their children (2). Fortunately, other states like California, Oregon and Washington, under the name of the West Coast Health Alliance, are developing their own traditionally strict vaccination mandates (3). Otherwise, this issue may become a ticking time bomb, since we know that if population vaccination rates are below around 80-90%, epidemics may arise eventually. Actually, we may predict which states may be first affected, since a recent article (4) showed the 10 states with the lowest (and highest) vaccination rates:
A screenshot of a questionnaire
AI-generated content may be incorrect.
In summary, let us learn from the 70-year history of polio and our 5 years’ experience with the pandemic of COVID-19 that revealed not only a rapid development of effective, safe vaccines against these viral diseases, but they also provide new guidelines for the prevention of similar epidemics. Our group recognized in 2020 that COVID-19 is not only the largest new human, social stressor, but it may lead to long-term chronic conditions (e.g., Long COVID) if not prevented or treated early (5-8). Namely, if we do not learn from history in science and social issues, we are destined to repeat the same mistakes. i.e., lose or delay the options for early prevention and treatment. After sad epidemics, look at the very recent good news (9): besides preventing acute infections, the COVID vaccine could prolong life for some cancer patients!
References
Inside Salk. Spring 2025. (La Jolla, CA)
Florida to eliminate vaccine mandates. Becker’s Hospital Review | Healthcare News & Analysis. Sept. 4, 2025.
3 states take vaccine guidance into their own hands: 5 notes. Becker’s Clinical Leadership, – Becker’s Hospital Review | Healthcare News & Analysis. Sept. 4, 2025.
10 states that vaccinate the most. Becker’s Hospital Review | Healthcare News & Analysis. Sept. 9, 2025.
Szabo S. COVID-19: New disease and chaos with panic, associated with stress.
Med. Sci., 2020, 59, 42-62. ISSN 1563-3950, www.mspsss.org.ua
Szabo S. Zourna-Hargaden P. COVID-19: New disease and the largest new human stressor. Integr. Physiol., 2020, 1 (4). DOI: 10.33910/2687-1270-2020-1-4-258-265
Szabo S., Zayachkivska O., Hussain A., Muller V. What is really ‘Long COVID’? Inflammopharmacology. Publ. online March 25, 2023. https://doi.org/10.1007/s10787-023-01194-0
Szabo S. The post‑COVID stress syndrome: from the three‑stage stress response of Hans Selye to COVID‑19. Inflammopharmacology. Publ. online May 15, 2023.
https://doi.org/10.1007/s10787-023-01179-z
COVID vaccine could prolong life for some cancer patients: Study. Becker’s Oncology. Oct. 23, 2025.
