Polio eradication: global failure with more ‘depressing’ news

Efforts to eradicate polio “They are failing” is a categorical statement made several months ago Global Polio Eradication Initiative (GPEI, English acronym). Since 2016, 3,300 children have developed vaccine-induced polio, with 665 cases reported in 23 countries in 2022 alone. The goal was to reduce cases polio type 2 vaccine-derived something that Aidan O’Leary, director of polio eradication at the World Health Organization (WHO), admits “clearly did not happen.” That reality has now become clear in A loop.

On July 16, the Gaza Health Ministry announced the discovery of poliovirus in six wastewater samples. Does this mean the virus is circulating in the Gaza Strip in the midst of the war against Israel. The GILE notes that while no cases of paralysis caused by the virus have been reported, there may be undetected cases.

Routine immunization coverage in the occupied Palestinian territory was optimal before the conflict began in October 2023 (99%), but fell to 89% in 2023.

The war has hit surveillance systems for all diseases, as well as water and sanitation facilities, and immunization campaigns: the level of routine immunization in the occupied Palestinian territory was optimal before the conflict began in October 2023 (99%), and this figure decreased to 89% in 2023, according to the latest WHO and UNICEF systematic immunization estimates (WUENIC).

“Tens of thousands of children under five years of age are currently at risk of contracting polio, and the possibility of contracting polio cannot be ruled out. international distribution outside the Gaza Strip.” This was stated by WHO representative Christian Lindmeier. It is not for nothing that the transmission of the infection in the Gaza Strip is coming from another country: it has been shown that the detected cases are associated with a strain of the type 2 virus obtained from a vaccine circulating in Egypt in the second half of 2023 and which could have been introduced into Gaza in September 2023.

PROGRESS ACHIEVED AND STEPS THAT NEED TO BE TAKEN

Important progress has been made in the fight against polio in recent years, as outlined in the GPEI report Polio Eradication Strategy 2022–2026. Wild poliovirus types 2 and 3 (WPV2 and WPV3) were declared eradicated in 2015 and 2019 respectively; the World Health Organization (WHO) South-East Asia Region was declared poliovirus-free in 2014, and the WHO African Region was certified as free of wild poliovirus (WPV) in August 2020.

The difficulty that has emerged in the Gaza Strip is that elimination of vaccine-derived viruses. Stopping the transmission of polio caused by immunizations is one of the main current challenges. This step was thought to have been achieved when immunity against poliovirus type 2 present in vaccines was eliminated in 2016, but this has not happened. In this regard, three new molecules are being developed that have shown their effectiveness in protecting against polio and preventing the reactivation of the weakened virus. The first, nOPV2, which targets type 2, is already in use in humans; the other two have just shown their effectiveness in mice.

The goal is to interrupt transmission of wild polioviruses and isolate the last vaccine-derived virus by the end of 2024, but this has not been achieved and is pushing back the next goal: poliovirus eradication in 2027 – wild virus and vaccine-free poliovirus. “To ensure that the world is polio-free, long-term containment of poliovirus in appropriately safeguarded settings will need to be implemented and monitored,” the GPEI says.