ASM Microbe reports that war has increased polio risks in Ukraine and abroad, disrupting health services in a country that has low immunization rates and a history of vaccine-derived polio outbreaks.
According to Dmytro Stepanskyi, MD, Ph.D., a representative of the American Society for Microbiology in Ukraine, although polio was declared eradicated in Europe in 2002, Europe remains at risk for transmission of wild poliovirus and the spread of vaccine-derived poliovirus (cVDPV) until global elimination is assured.
In recent years, Ukraine was thought to be in high danger of a polio outbreak, according to Dmytro, who is the poliovirus containment coordinator at Dnipro State Medical University and the chairman of the department of microbiology, epidemiology, virology, and immunology. Years of low vaccination coverage in Ukraine have resulted in a large population of children that are unvaccinated or under-vaccinated, making them vulnerable to polio.”
To estimate the polio hazard in Ukraine, Stepanskyi and colleagues conducted epidemiological, clinical, and virological analyses of cVDPV cases in 2021, surveillance data, and reports from expert group meetings.
An outbreak of polio in Ukraine in 2015 was attributed to cVDPV1 type 1 (cVDPV1), which primarily affected children living in southwestern Ukraine. They said a statewide additional immunization program coupled with epidemic response efforts failed to increase the vaccination rate with three doses of polio vaccine to 95 percent.
In 2021, there were two more cases reported: an acute flaccid paralysis disease in a 17-month-old girl in Rivne Province and another in a 2-year-old boy in Zakarpattya. In Rivne and Zakarpattya, the girl’s family and community contacts, as well as four more family members, tested positive for the disease but did not show any paralytic symptoms.
In a recent examination, it was determined that the newly discovered poliovirus had the same genetic makeup as a sample taken between 2020 and 2021 in Dushanbe, Tajikistan.
In Ukraine, the researchers rated the danger of diffusion as high due to low immunization coverage (73.3 percent as of December 2021) and gaps in regional vaccination. The outbreak in Rivne and Zakarpattya provinces of western Ukraine was declared a public health emergency in January after 19 isolates from two provinces were verified.
Based on these cases, the Ministry of Health approved a comprehensive polio outbreak response plan, which involved increasing environmental surveillance, and catching up on polio vaccine immunizations with inactivated polioviruses starting Feb. 1, 2022, as well as preparing two nationwide oral polio vaccine campaigns.
Immediately after, Russia launched an attack on Ukraine on February 24, which affected 15.7 million people and required medical care for 12.1 million, according to Stepanskyi. According to the authors, among the essential services affected by the attacks are tuberculosis testing and treatment, routine vaccinations, and responses to the polio outbreak.
“The ongoing cVDVP2 outbreak and limited uptake [in the] mass immunization campaign has resulted in a high risk of poliovirus circulation,” Stepanskyi stated. “There is a risk of polio spreading to neighboring countries.”