The World Health Organisation (WHO), along with its partner Global Polio Eradication Initiative (making it the largest public-private partnership for health), is on a mission to reach every last child with polio vaccine, thereby ensuring a polio-free world for the generations to come. They believe that their work has reduced polio by 99% and that polio survives only among the world’s poorest and marginalised communities.
Polio, or poliomyelitis, is a highly infectious disease caused by a virus and can totally paralyse a person in a few hours. Mainly affecting children under the age of five, the virus is transmitted by person-to-person, often through the faecal-oral route, and multiplies in the intestine. Polio can lead to irreversible paralysis, usually in the legs, and even death, when the breathing muscles become immobilised.
Polio can be prevented
Even though there is no cure for polio, it can be prevented. If children are administered polio vaccine multiple times, then they can be protected for life. The vaccine to prevent polio is available in two forms: oral polio vaccine (OPV) and inactivated polio vaccine (IPV). Albert Sabin, a Polish-American physician and microbiologist, is best known for developing the OPV.
Albert Sabin
Born in Bialystok, Russia (now in Poland) in 1906, Sabin immigrated with his parents to the U.S. in 1921 and became an American citizen. He switched to Medicine from his dental education after he was drawn towards the science of virology with a dream of conquering diseases – the effect of reading American microbiologist Paul de Kruif’s “Microbe Hunters”.
Not a one-virus virologist
Sabin showed promise early in his chosen career and started his research on polio when he got his chance. Considering that polio was reaching epidemic proportions, not just in the U.S. but the entire world, Sabin couldn’t have picked a better time for it.
His polio research was interrupted during World War II, when he served in the U.S. Army Medical Corps, but it was during this phase of his life that he developed vaccines for encephalitis and dengue fever and also investigated sand-fly fever.
Sabin was able to demonstrate that polio viruses primarily infected the digestive tract, as opposed to the prevailing theory that they infect only nervous tissues after entering humans through the nose and respiratory system. When the first polio virus in human and monkey non-nervous tissue cultures were grown by others in 1949, the race to develop an effective vaccine burst open.
Salk vs Sabin
Sabin believed that an attenuated (weakened) live-virus vaccine administered orally would provide immunity for a longer period than killed, injected virus. Jonas Salk, an American virologist who believed in the killed polio virus, seemed to have won the contest when he announced his vaccine in 1953. Salk’s vaccine proved to be safe and effective, even though it had to be injected every three years or so, and started winning over people in the U.S.
Undeterred, Sabin continued to work towards his vaccine, which he knew would be long lasting and could be orally administered, without the need for injections like in Salk’s vaccine. He isolated strains of each of the three types of the virus that would stimulate the production of antibodies, but weren’t strong enough to lead to the disease itself.
Following meticulous experiments on thousands of monkeys and hundreds of chimpanzees, Sabin tested the three strains on himself and other volunteers. On October 6, 1956, Sabin announced that his vaccine was ready for mass testing.
The public and most of the scientific community in the U.S., however, still backed Salk’s vaccine. The large-scale clinical trial of Sabin’s vaccine instead happened in the Soviet Union. Millions of Russian children were provided the vaccine in the next several years, protecting them from polio.
Gets WHO backing
Once Sabin’s vaccine received the backing of the WHO, it was only a matter of time before it became the main defence against polio in the entire world. Until his death in 1993, Sabin continued to work tirelessly for his cause.
Since 1988, wild polio virus cases have decreased by 99% – from nearly 3,50,000 cases in over 125 countries, to 33 reported cases in 2018. The ease of administering Sabin’s vaccine (OPV), as it can be orally given by either professionals or even volunteers, has meant that it has been a mainstay in our effort to be rid of polio forever.
