In August 2020, the African region celebrated a significant victory: it was declared free of indigenous wild poliovirus. This was a monumental achievement in the global fight against polio, a disease that can lead to paralysis and even death. However, this success is now facing a new challenge. There is an urgent threat from a different type of poliovirus known as the type 2 variant poliovirus (cVDPV2). This year alone, 290 cases of this virus have been reported in 23 African countries.
The Need for Vaccination
As countries across Africa ramp up their vaccination efforts to protect children from this virus, one of the most critical components of the response is early and accurate detection of the poliovirus. The sooner a virus can be identified, the quicker health authorities can respond to prevent its spread.
To boost these efforts, the World Health Organization (WHO) Regional Office for Africa (WHO AFRO), along with the United States Centers for Disease Control and Prevention (US CDC) and the Gates Foundation, is working to equip and train laboratories throughout Africa. They are introducing advanced Sanger sequencing technology, an innovative method that will help scientists explore new regions in the poliovirus genome.
Understanding the Poliovirus
The poliovirus has a genome that is 7.5 kilobases long. This might sound complicated, but in simpler terms, it means that the virus has a set of genetic instructions that dictate how it behaves. The genome includes a main part that is used to create four proteins, labeled VP1 to VP4. Among these, the VP1 protein is especially important because it helps the virus attach to cells in the human body. Understanding these proteins is crucial for tracking and managing the spread of poliovirus.
In 2024, WHO AFRO initiated targeted training focused on Advanced Sanger Sequencing. This training aims to diversify the ways laboratories can diagnose polioviruses, ultimately reducing the time it takes to detect the virus. These trainings are essential for lab personnel, providing them with the skills needed to operate advanced sequencing technologies and deliver timely results to public health decision-makers.
The Importance of Sequencing
Sequencing allows laboratories to pinpoint genetic changes in poliovirus strains. This is important for tracking how the virus spreads and evolves. With this level of precision, health officials can quickly identify mutations, making it easier to detect emerging threats. Until now, sequencing had been limited to the VP1 region of the virus, but after this training, labs will be able to analyze more areas of the poliovirus genome, which enhances their ability to classify cases accurately.
Irene Turyahabwe, a participant from Uganda, expressed her excitement about this development, stating, “Expanding our sequencing window to the other regions of the poliovirus, alongside the VP1 region, enhanced our ability to classify cases more accurately—bringing us one step closer to polio eradication.”
Training for Success
The first round of training took place in South Africa, where laboratory personnel gained hands-on experience with Advanced Sanger Sequencing techniques. This training is part of the Global Polio Eradication Initiative (GPEI) and is vital for ensuring that countries can quickly and accurately detect polioviruses. Delays in detection can hinder effective response efforts, so this training is essential for strengthening public health systems across the continent.
Following the success in South Africa, WHO plans to expand the training to other key countries in Africa. Algeria, Central African Republic, and Madagascar are among the next in line. This regional expansion aims to prepare multiple countries to contribute effectively to the fight against polio in Africa.
Strengthening Surveillance
In addition to the training, WHO is supporting 16 polio laboratories in Africa that provide environmental surveillance. This means they test for poliovirus in stool and wastewater samples to track how the virus spreads geographically. By enhancing laboratory capacity to process samples quickly, there is a stronger surveillance network across the region. This collaboration is vital in eradicating polio once and for all.
The Broader Context
The fight against polio is particularly challenging in fragile and conflict-affected areas. According to UNICEF, 85% of the 541 children diagnosed with polio in 2023 live in such environments. In these regions, children are not only facing the threat of polio but also the impacts of conflict that can disrupt healthcare systems and displace families.
Catherine Russell, the Executive Director of UNICEF, emphasized the dire situation: “In conflict, children face more than bombs and bullets; they are at risk of deadly diseases that should no longer exist.” The collapse of healthcare systems and the destruction of water and sanitation infrastructure can lead to a resurgence of diseases like polio. Many children are left paralyzed, unable to walk, play, or attend school due to this preventable disease.
The Decline in Immunization
Another contributing factor to the rise in polio cases is the decline in childhood immunization. Even countries that had been polio-free for years are now experiencing outbreaks. UNICEF reminds us that the global spread of polio is a stark reminder that children everywhere remain at risk until all forms of polio are eradicated.
Moving Forward
The fight against polio is ongoing, but with concerted efforts and innovative technologies like Advanced Sanger Sequencing, there is hope. Strengthening laboratory capabilities, expanding vaccination programs, and fostering international cooperation are all essential steps in this battle.
The commitment to eradicating polio not only protects the health of children today but also safeguards future generations. Together, we can build a world where no child has to suffer from this preventable disease.
As we move forward, the words of Dr. Jude Kfutwah, coordinator of the Regional Polio Laboratory Network at the WHO Regional Office for Africa, resonate strongly: “Advanced sequencing will not only open different diagnostic windows for efficient and rapid diagnosis but will also provide much-needed evidence for the success of specific vaccination campaigns essential for ongoing polio eradication efforts.”
The path to a polio-free world may be challenging, but with determination, innovation, and collaboration, we can achieve this goal. The time to act is now, and every effort counts in the quest to eradicate polio for good.
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