NUNZIUM

Researchers led by Andrew Macadam at the UK's National Institute for Biological Standards and Control have developed a "super-engineered" vaccine to combat vaccine-derived polio strains. This groundbreaking vaccine has shown promising results in initial tests and is now undergoing human trials. Since 1988, global efforts have eradicated two of the three poliovirus subtypes, with only 21 cases of wild polio reported in the past year. However, there have been 665 cases of vaccine-derived polio across 23 countries, primarily in sub-Saharan Africa.

The Covid-19 pandemic and conflicts in polio-vulnerable countries have contributed to the rise in cases. The new vaccines use genetic engineering to lower the risk of the attenuated virus reverting to a virulent state. Over 650 million children in 30 countries have received the nOPV2 vaccine since March 2021. However, nOPV2 has regained virulence four times, highlighting the need for comprehensive public health initiatives. The global polio management is transitioning from the Global Polio Eradication Initiative to national immunisation and disease-surveillance programmes, with the World Health Organisation enacting a country-specific approach.

The "super-engineered" polio vaccines aim to prevent the virus from mutating into dangerous forms that can cause outbreaks and paralysis. Oral vaccines contain weakened live polio viruses, and the genetic redesign locks them into that weakened state. US and UK teams have developed upgraded vaccines against all three types of polio. Researchers have genetically altered the weakened virus to make it much harder for it to cause paralysis, resulting in a vaccine that is 50 to 100 times more stable.

In March 2021, the World Health Organization made the researchers' vaccine against type-two polio available for emergency use, and it has since been used more than 650 million times. Researchers have now detailed the creation of stable vaccines against polio types one and three in the journal Nature. First-stage human trials of the upgraded vaccines have been conducted, with "very promising" data. These are the first new polio vaccines in 50 years.

Eradicating polio requires reaching every child with vaccines, which has been a challenge in some of the poorest and most conflict-ridden parts of the world. More stable vaccines are a "significant part" of the plan for a polio-free world, but vaccination coverage is crucial. Vaccine-derived polio outbreaks are causing problems in places facing complex humanitarian emergencies, such as the Democratic Republic of Congo and Yemen. Oral polio vaccines are no longer used in the UK and other countries with established healthcare systems, which have moved to the polio injection.

In conclusion, the development of the "super-engineered" polio vaccine is a significant milestone in the fight against polio. These genetically altered vaccines offer a more stable and effective solution to combat vaccine-derived polio strains. However, the success of these vaccines relies on reaching every child in the most vulnerable regions of the world. With continued global efforts and collaboration, a polio-free world may soon become a reality.