Drs Jonas Salk & Albert Sabin's vaccines to defeat polio - guest post

Polio patients inside iron lungs

Guardian

Before the mid-1950s, panic gripped countries as polio spread globally. Paralytic polio­myeli­tis caused an infection in the cen­t­ral nervous sys­tem, lead­ing to muscle weakness and paralysis. Child­ren were most at risk: thousands were left severely impaired, and the disease killed 2-10% of people who cont­racted it. 1950s school pupils will remember that even children who sur­vived the disease faced long-term issues. Deformed limbs requ­ir­ed leg braces or wheel­chairs, and some needed to breathe via the horrid iron lung.

Parents panicked, trying to keep their children safe: An edict barring children under 7 from school and other pub­lic places was promulgated, perhaps pos­t­­pon­ing the opening of all grades if the situation worsened. Local public heal­th authority advised parents to keep young children in their backyards: alone!

As families clamoured for research into the deadly polio disease, two young doctors searched for cures. Albert Sabin (1906-1993) was born in Bialystok Poland, facing intense anti-Semitism. In 1921, at 15, Albert’s parents moved him to New Jersey to join relat­ives. A brill­iant student, Albert soon learned English well enough to excel in high school.

One of Albert’s uncles was a dentist and he promised to pay for Al­b­ert’s dentistry training. Albert enrolled in New York University; he loved me­dicine and science, but not dentist­ry. So he took extra jobs and schol­­ar­­ships to finance medical school alone. He graduated in Medicine at N.Y Uni in 1931, the year a major polio outbreak panicked N.Y, so Sab­in de­cided to devote him­self to polio resear­ch. He trained as a pathol­ogist, studying in London and New York be­f­ore moving in 1939 to study viruses at Cincin­n­ati’s Chil­dren’s Hos­pital Research Foundation

Dr Albert Sabin (above)

Aish

Dr Jonas Salk 

Washington Post

                                                                          

In WW2 Dr Sabin became a Colonel in the Medical Corps, study­ing viruses affecting American troops. He studied sand-fly fever which was damaging troops in North Africa; he showed that the disease was be­ing spread by mos­quitoes and that mosquito rep­el­lent helped reduce the dis­ease. Sabin also conducted vital wartime re­s­earch on dengue fever, toxo­pl­as­mosis and encephalitis. A vaccine he co-develop against en­ce­ph­alitis was given to c70,000 American troops pre­paring to invade Japan.

Jonas Salk (1914-1995) was born in the Bronx NY to a poor, large Jew­ish family. Early on, Jo­nas realised he wanted to change the world via med­ic­al re­s­earch. He went to City College and New York University’s Medical School. In 1947, Prof Salk at Pittsburgh University School of Medicine undertook a long project to determine the number of diff­erent types of poliovirus and to develop a vaccine against polio. Did he know that in 1949, a poliovirus was successfully cultivated in human tissue by John Enders, Thomas Weller and Frederick Robbins at Boston Children’s Hospital, recognised with the 1954 Nobel Prize? 

Dr Sabin made a big discovery: polio was caused by a virus that lived in the small intestines of infected people. He real­ised a vaccine might prevent the virus from enter­ing the blood­stream, stop­ping it from spread­ing into int­estines. Yet some polio vacc­ines tragically ended in the paralysis of patients, or worse, in death. As the 1950s advanced, po­l­io increased and the public needed an effect­ive vaccine.

Dr Salk was part of a prestigious team surveying all U.S polio ca­ses when it became clear that any effective vaccine would have to cont­ain str­ains from 3 distinct polio var­iat­ions. Dr Salk was undeterred, and his self-confidence irritated other resear­ch­ers, but the research team be­lieved they were correctly focused. Salk drew on recent res­earch about growing vaccines in animal tissues under laboratory conditions, cultiv­at­­ing polio viruses in monkey kidney cells. He then killed these virus cells using formaldehyde. Salk’s goal was to develop a vaccine using dead polio cells, clashing with conventional medical wisdom.

Meanwhile Sabin was growing a live-cell vac­c­ine. His vaccine had the ad­vantage of us­ing manipulated polio cells: since these were not the same cells that caused diseases in humans, it was thought that Sabin’s live virus vaccine was safer. It also had the advantage of being able to be administered orally, instead of through an injection as the dead virus vaccines were. Professional rivalry continued.

Salk’s dead cell vaccine had been tested only on anim­als, since offic­ials feared testing it on humans. So in 1954 Salk injected his vaccine into him­self, his wife and child­ren, the first humans to be vac­cinated with this inv­ention. When no ill effects occurred, the world begged for his vaccine.

Also in 1954 the charity March of Dimes arranged a large-scale polio trial for a million children aged 6-9. The trial was given major media coverage, alien­ating many scientists and doctors; they still saw Dr Salk as over-confident. Nonetheless finding a vaccine for polio was the top priority. Half the children in the trial received Salk’s vaccine and the other half received placebos. Dr Salk had succeeded.

At a press con­f­­er­ence at Michigan Uni in Ap 1955, 50,000+ doctors viewed the broad­cast in theatre scr­eenings while ordinary citizens tuned into the radio. When it was announ­ced that Dr Salk’s pol­io vacc­ine was both safe and eff­ective, ch­urch bells rang; parents of young children wept; drug compan­ies started production of Salk doses.

Polio vaccine

BBC

In 1956, Sabin travelled to Russia to work with Russian virologists. He created a team with Dr Mikhail Chumakov, the man responsible for Salk vaccine tests in the Sov­iet Un­ion, performing init­ial tests of the live-attenuated vaccine us­ing a Sabin seed virus. Trials were car­ried out on millions Russian children in 1958 and 10 mil­l­ion children in 1959, and on Czech and Hungarian children in Dec 1959.

Remember Dr Sabin’s vaccine could be taken orally, without needing follow-up doses. By the mid-1960s, Dr Sabin’s became the preferred vaccine in the U.S.

After abolishing polio, the two doctors diverged. Jonas Salk conducted research on AIDS in the 1980s. His greatest post-polio success was est­ablishing San Diego’s Salk In­stitute for Biological Scien­ces, bring­ing scient­ists together. Albert Sabin con­ducted research into can­cer, becom­ing pres­id­ent of the Weizmann Inst­itute of Science in Israel in 1970, until illness intervened. Sabin died in 1993 at 86, while Salk died in 1995 at 80. By then pol­io was a disease of the past. Their vaccines had saved thousands of lives and changed society, but neither ever patented the vaccines!

Dr Joe