wongnaah1_AAMIR QURESHIAFP via Getty Images_ipv AAMIR QURESHI/AFP via Getty Images

The Only Way to Eliminate Polio

Despite playing a crucial role in the success of global efforts to eradicate the virus, the affordable and easy-to-administer oral vaccine has outlived its usefulness. Conquering the disease once and for all requires ending the strain that has emerged from the live virus as well.

STOCKHOLM – When Jonas Salk’s polio vaccine was found to be safe and effective in 1955, following a successful trial involving nearly two million American children, it marked a turning point in the fight against a highly infectious disease causing incurable paralysis or even death. Prior to Salk’s discovery, between 25,000 and 50,000 cases were recorded each year in the United States alone, and little was known about how the virus spread.

Salk created his injectable inactivated polio vaccine (IPV) by treating the virus with formalin. Around the same time, Albert Sabin was developing an oral polio vaccine (OPV), which uses attenuated (weakened) mutant strains that stimulate antibody production without causing the disease. Cheaper and easier to administer than Salk’s vaccine, Sabin’s live-virus version ultimately became more widespread in the global effort to eradicate polio, although it was introduced six years later.

The success of that effort cannot be overstated. Since 1988, when the World Health Assembly adopted a resolution to eliminate the disease worldwide and subsequently launched the Global Polio Eradication Initiative, wild polio cases have plummeted by more than 99%, from an estimated 350,000 cases to six reported cases in 2021. Two of the three strains of wild poliovirus have been eradicated, while the third remains endemic in only Pakistan and Afghanistan. This breakthrough can be attributed largely to mass immunization, but also to improved sanitation and hygiene.

https://prosyn.org/W6OI3xu