Polio vaccination coverage has declined globally, from 86% in 2019 to 80% in 2021. Several countries are experiencing an upsurge in poliomyelitis. There is a need to increase vaccination efforts and provide safe sanitation facilities.
According to the World Health Organization (WHO), global polio vaccination coverage among children one year fell from 73% in 2000 to 86% in 2019 to fall to 80% in 2021. Experts attribute this decline to the negative impacts of the COVID-19 pandemic.
"As many as 17 million people have likely not received a single vaccine during the year, compounding the already immense inequalities in access to vaccines," the WHO explained in a statement released in 2021. .
Health experts are calling for more action to eliminate poliomyelitis, a viral disease transmitted by coughing and sneezing or through objects contaminated with the feces of an infected person. It can be prevented by vaccination.
If a population is fully immunized, they will be protected against all forms of poliovirus and will not suffer from paralysis, a common effect of the disease.
Two types of vaccines exist to fight polio: injected polio vaccine (IPV), given by injection, and oral polio vaccine (OPV), given as drops in the mouth.
While IPV contains poliovirus that has been killed, OPV contains inactivated virus that is incapable of causing disease, according to a article published in the journal Ethics, Medicine and Public Health on November 24.
OPV, which is commonly used around the world, can mutate as it multiplies in the gut, the paper adds.
While these mutations rarely cause disease in vaccinated people, vaccine-derived variants known as circulating vaccine-derived poliovirus (VDPV) can cause poliomyelitis just like wild poliovirus (WPV) in unvaccinated people.
The article highlighted the resurgence of polio types around the world. For example, in 2019, VDPV cases were reported in only 19 countries, but by April 2022 the number had risen to 33 countries.
“These are mostly socio-economically disadvantaged countries with conflict zones. The re-emergence of polio cases is a fact, and the international community should take immediate action,” added Abdulqadir J. Nashwan, Director of Nursing for theeducation and development at Hamad Medical Corporation in Qatar.
The downside of polio eradication in Africa
Thanks to the support of African governments and global donors, the WHO African Region was certified wild polio-free on 25 August 2020 by the African Regional Certification Commission after four years without case detection.
“Ending wild poliovirus in Africa is one of the greatest public health achievements of our time and gives us all a powerful inspiration to finish the job of eradicating polio globally,” said the Director General. of the WHO, Tedros Adhanom Ghebreyesus, in a communicated announcing this feat.
But the WHO has also urged countries to continue the fight against polio, as circulating vaccine-derived poliovirus type 2 (cVDPV2) is still present in 16 countries in the WHO African region.
For example, from 2008 to 2018, Ghana enjoyed polio-free status until an outbreak of cVDPV2 occurred in 2019, according to the International Vaccine Alliance, GAVI.
Between December 2019 and February 2020, the country's Ministry of Health, with support from WHO, GAVI and UNICEF, vaccinated 4,5 million at-risk children in half of the country's 16 regions.
However, in Ghana, as in many places, the COVID-19 pandemic has halted immunization, setting back global polio eradication efforts. Several countries, including Malawi and Mozambique, have seen a resurgence of the disease.
“Due to the restrictions, outreach workers could not come to homes to vaccinate children, and parents could not bring their children to health facilities for vaccination,” Nashwan explained.
He added that misinformation and myths related to the impact of vaccines was another contributing factor and that deficits in funding due to the post-COVID-19 financial crisis had also played a role.
How to reverse the trend
Nashwan is convinced that Africa can turn the tide, but he cautions: "despite the existence of constantly improving vaccines, their availability alone does not hold the key to the solution."
“As always, immunization rates are critical to eradicating polio globally. To get there, nations must recognize the potentially crippling physical and economic effects of the virus on a population. It is important to dispel vaccine myths and support a stricter vaccination campaign,” he added.
Shiphrah Kuria-Ndiritu, reproductive, maternal, child and adolescent health expert at Amref Health Africa, agrees in the same direction.
"There is a need to expedite the targeting of those who missed the vaccines and ensure that all newborns receive the vaccines on schedule," she told SciDev.Net.
“African countries must continue to invest in routine immunization efforts by building capacity health workers, strengthening the supply chain and increasing demand at the community level.
Increased efforts to provide clean water and sanitation services are also crucial to stopping the spread of the virus, she added.
This article was supported by Global Health Strategies (GHS), an organization that uses communication and advocacy to help bring about profound change in health and development across the world.