Poliomyelitis has been one of the most dreaded word among parents in the world. In the early 20th century, polio was one of the most feared diseases in developed countries, paralyzing hundreds of thousands of children every year. Even in the U.S., parents kept their children out of school when they heard of a child with polio.
A highly infectious disease caused by a virus, polio invades the nervous system and can cause total paralysis in a matter of hours. The virus is transmitted by person-to-person spread mainly through the fecal-oral route or, less frequently via contaminated water or food. The virus multiplies in the intestine. Initial symptoms are fever, fatigue, headache, vomiting, stiffness of the neck and limb pain.
Soon after the introduction of effective vaccines in the 1950s and 1960s however, polio was brought under control and nearly eliminated as a public health problem in these countries. But the developing world lagged behind, and it took additional years for polio to be recognized as a major threat to children there. As a result, 1970s routine immunization was introduced worldwide as part of national immunization programs, helping to control the disease in many developing countries.
The incurable disease is contracted mostly by children under the age of five. One in 200 infections leads to irreversible paralysis, and among those, 5% to 10% die when their breathing muscles are unable to function. Cases due to wild poliovirus have decreased by over 99% since 1988, when there were an estimated 350,000 cases. If a single child remains infected, children in all countries are at risk of contracting polio.
In most countries, the global effort has expanded capacities to tackle other infectious diseases by building effective surveillance and immunization systems. As there is still no cure for polio, it can only be prevented – and polio vaccine – given several times to children can protect for life.
Of the 3 strains of wild poliovirus (type 1, type 2, and type 3), wild poliovirus type 2 was eradicated in 1999, and no case of wild poliovirus type 3 has been found since the last reported case in Nigeria in November 2012.
In 1988, the 41st World Health Assembly of the World Health Organization (WHO) adopted a resolution for the worldwide eradication of polio. It marked the launch of the Global Polio Eradication Initiative (GPEI), spearheaded by national governments, WHO, Rotary International, the US Centers for Disease Control and Prevention (CDC), UNICEF, and supported by key partners including the Bill & Melinda Gates Foundation.
In 1994, the WHO Region of the Americas was certified polio-free, followed by the WHO Western Pacific Region in 2000 and the WHO European Region in June 2002. On 27 March 2014, the WHO South-East Asia Region joined them, with no transmission of wild poliovirus in this bloc of 11 countries stretching from Indonesia to India. This achievement marks a significant leap forward in global eradication, with 80% of the world’s population now living in certified polio-free regions. More than 16 million people who would otherwise have been paralyzed. are able to walk today.
Polio still exists only in Pakistan, Nigeria and Afghanistan, but failure to stop polio in these last remaining areas could within a decade bring about as many as 200,000 new cases every year all over the world.
Once polio is eradicated, the world can celebrate the delivery of a major global public good that will benefit all people equally, no matter where they live. Economic modelling has found that the eradication of polio would save at least $40 billion to $50 billion, mostly in disadvantaged countries.
In 1988, when the Global Polio Eradication Initiative began, polio paralyzed more than 1,000 children around the world every day. Since then, more than 2.5 billion children have been immunized against polio thanks to the cooperation of more than 200 countries and 20 million volunteers, backed by an international investment of more than $ 11 billion.
But wiping out the last 1% of polio cases has proved difficult because of political instability, conflict, hard-to-reach populations and poor infrastructure.
The development of effective vaccines to prevent paralytic polio was one of the major medical breakthroughs of the 20th century. The Global Polio Eradication Initiative uses two types of vaccine to stop polio transmission – inactivated polio vaccine that is injected and oral polio vaccine that comes in the form of oral drops.
Israel, which also has eradicated polio, is now at the forefront of the international struggle to eradicate polio. A prestigious research grant from the WHO has been awarded to Dr. Tomer Hertz for the development of an innovative approach to measuring immune responses to polio. The Hebrew University of Jerusalem graduate in microbiology, immunology, genetics and computational neuroscience now works at the microbiology and immunity department of Ben-Gurion University of the Negev and the the National Institute of Biotechnology in Beersheba.
The prestigious WHO grant will be used to develop an alternative and safe test for diagnosing and measuring immune responses to polio in the population. The innovative test will be based on a killed virus and recombinant proteins of the virus, thus not posing a risk of recurrence of the disease.
In 2016, the use of live vaccines of this type was banned so the wild poliovirus would not escape into the population. To prevent a renewed outbreak, new guidelines issued by the World Health Organization to the laboratories allowed individual laboratories worldwide to continue working with the live virus under strict safety conditions. The organization hopes that in the foreseeable future, the two additional types of polio types 1 and 3 will disappear, and identical guidelines will come into effect.
Alongside the new guidelines, and parallel to those licensed laboratories that do not exist in Israel and other countries, there is a need to continue research on the polio virus so as to periodically monitor and monitor the efficacy of the vaccine in the general population, explained Hertz. “The WHO is now looking for new and safe methods to measure the response to a vaccine that does not involve a live virus and to prevent it from spreading again. Our proposal …is to develop a new method for measuring immune responses to polio based on parts of a dead virus.”
Hertz’s lab focuses on systemic immunology and the study of viruses and vaccines against them and specializes in a unique technology for the measurement of immunological profiles based on chips printed on various antigens; these will be used by the research team to develop new diagnostics for polio using killed antigens. We hope this will lead to a effective and inexpensive alternative to the existing test and be used on patients.
Last year, Hertz was awarded two research grants by the US National Institutes of Health (NIH) in collaboration with American research institutions.