Latest news with #nOPV2
Medscape
2 days ago
- Health
- Medscape
Novel Polio Vaccine Matches Traditional in Immune Response
The novel oral polio vaccine type 2 (nOPV2) induced intestinal mucosal immune responses comparable to those induced by the traditional Sabin monovalent oral polio vaccine type 2 (mOPV2) across different age groups, with the strongest responses observed in infants. METHODOLOGY: The novel nOPV2 is a more genetically stable vaccine and carries a lower risk of reverting to neurovirulence than mOPV2 and has been deployed to interrupt vaccine-derived poliovirus type 2 outbreaks. Researchers compared intestinal mucosal immune responses induced by the first dose of nOPV2 and mOPV2 across different age groups: Infants aged 18-22 weeks, children aged 1-4 years, and adults aged 18-50 years. They included participants from four clinical trials: 47 infants, 47 children, and 66 adults enrolled in the nOPV2 trials, and 42 infants, 46 children, and 100 adults in the mOPV2 control trials. They used serum samples collected on day 0 (the day of the nOPV2 or mOPV2 challenge) and on day 28 to measure poliovirus type 2-specific serum neutralization. They used stool samples collected daily for the first 10 days and then weekly from day 14 to day 28 for the evaluation of viral shedding. TAKEAWAY: Overall, both nOPV2 and mOPV2 induced similar intestinal poliovirus type 2-specific neutralization and immunoglobulin A responses on day 14 across all age groups, with no significant differences observed between the two vaccines. Among OPV2-naive participants who received nOPV2, an age-related decline in response rates was observed: 82% of infants, 61% of children, and 25% of adults showed detectable poliovirus type 2-specific neutralization on day 14. Among children, nOPV2 recipients showed higher viral shedding rates than mOPV2 recipients (92% vs 44%; P < .0001), potentially due to differences in prior vaccine exposure; however, no differences in viral shedding rates were observed among adults or infants. < .0001), potentially due to differences in prior vaccine exposure; however, no differences in viral shedding rates were observed among adults or infants. Adults with prior OPV2 exposure showed lower viral shedding rates than OPV2-naive adults (20% vs 82%; P < .0001) when challenged with nOPV2, despite similar neutralizing activity and immunoglobulin A responses. IN PRACTICE: 'This study's findings affirm the utility of nOPV2 as an important tool to address the ongoing cVDPV2 [type 2 circulating vaccine-derived poliovirus] outbreaks,' the study authors wrote. SOURCE: The study was led by Audrey Godin, MD, London School of Hygiene & Tropical Medicine, London, England. It was published online on April 30, 2025, in The Lancet Microbe . LIMITATIONS: A significant limitation was the time gap between the mOPV2 trials conducted in 2015-2016 and the nOPV2 trials conducted in 2018-2019. The lack of stool samples after day 14 prevented the study of long-term mucosal immunity. Additionally, as the study focused on fully vaccinated healthy infants, young children, and adults, the results may not be generalizable to immunodeficient individuals, older children, adolescents, unvaccinated or incompletely immunized individuals, or populations in countries with different socioeconomic conditions. DISCLOSURES: This study was funded by the Bill & Melinda Gates Foundation and Japan Agency for Medical Research and Development. The authors declared having no conflicts of interest.
Zawya
11-04-2025
- Health
- Zawya
Ethiopia reaches 15.3 million children with novel oral polio vaccine, surpassing target
For Meseret Gelaw, a mother in Furustale village of Jimma town in Oromia region, ensuring that her 8-month-old son receives every necessary vaccine is a matter of life and health. 'I want my child to grow up healthy, free from diseases like polio. When I heard about the vaccination campaign, I made sure he was among the first to receive the polio vaccine,' Meseret shared, holding her son tightly after the procedure. Meseret is one of millions of parents in Ethiopia who participated in the recent polio vaccination campaign which took place from 22 to 25 February 2025 in ten regions of the country. Over 15.3 million children aged under 5 years were vaccinated with the WHO-prequalified type 2 novel oral polio vaccine (nOPV2). The campaign surpassed the initial target of 14.8 million, with an impressive coverage of 103%. Around 104 000 zero-dose children (those who have never received any vaccination) were identified, and almost 62 000 (around 60%) were vaccinated. The campaign kicked off with a high-level launch in Ethiopia's Somali region, attended by Dr Dereje Duguma, the State Minister of Health. During the launch, Dr Duguma emphasized the importance of vaccinating all children, regardless of their vaccination history. "This integrated polio vaccination will create an opportunity to reach under-vaccinated or unvaccinated children who missed their routine vaccinations," he said, urging caregivers and parents to seize this vital opportunity. The launch also graced by the presence of the Somali Regional President, Mr. Mustefa Mohamed. 'This campaign will play a pivotal role in the polio eradication effort. Strengthening integration is key to achieving positive health outcomes. Our region will work hard to make the campaign successful, including raising awareness and mobilizing the community.', said Mr Mustefa. The campaign employed a house-to-house approach, which not only reached children with polio vaccine but also helped identify zero-dose and under-vaccinated children for immunization. Additionally, the campaign was integrated with other health interventions and consequently 1491 children with clubfoot were identified and referred for corrective interventions. Dr Fadinding Manneh, Global Polio Eradication Initiative (GPEI) Coordinator for Ethiopia speaking on behalf of GPEI partners, highlighted the crucial role of integrated interventions during the campaign. 'We remain committed, together with all global immunization partners, to support the regions, zones and woredas to achieve high coverage in all integrated interventions and to boost population immunity and to prevent vaccine preventable diseases and clubfoot,' he said. Throughout the campaign, WHO, working closely with the Ethiopian Public Health Institute and UNICEF, played a pivotal role in ensuring the campaign success. From pre-campaign preparations, such as resource mobilization and the Ttraining of Trainers (ToT) for more than 90health workers, to real-time monitoring using tools like the Open Data Kit (ODK) - an open-source suite of tools designed for data collection in resource-constrained environment, contributing significantly to the campaign's logistical and operational effectiveness. Independent monitors and quality assurance surveyors were deployed in nearly half of the selected regions to assess the quality of the campaign, while feedback from the field was used to correct any issues immediately, ensuring higher coverage rates. Additionally, WHO Field Officers and Stop Transmission of Polio (STOP) team consultants supported the assessment of preparedness levels and involved in the micro planning process, cold chain inventory and the facilitation and training of the deployed team supervisors. In the post-campaign phase, targeted mop-up activities were conducted in areas with poor coverage, and children who were missed due to absence or other reasons were revisited and vaccinated. Ethiopia introduced the nOPV2 vaccine in October 2021 to address the outbreak of circulating vaccine-derived poliovirus (cVDPV). cVDPV occurs when the weakened virus from the oral polio vaccine (OPV) sheds in a vaccinated child's feces and circulates among unvaccinated children, potentially mutating into a more dangerous form that can cause paralysis. This variant virus typically spreads in areas with low vaccination coverage, where many children remain unvaccinated. With financial support from the Gates Foundation and Rotary International, through WHO and UNICEF, the campaign aimed not only to vaccinate children but also to provide critical support for the global fight against polio. For Meseret, like many other mothers, the vaccination campaign represents a powerful step toward ensuring a healthier, polio-free future for her child. 'It's a relief to know that my son is now protected,' she said. This simple act, she believes, could safeguard her child's future from the devastation that polio once caused. Ethiopia is one of the 24 countries in Africa implementing the Big Catch-up campaign, an initiative which aims to vaccinate millions of children who missed routine immunizations. The Big Catch-Up campaign is vital for ensuring that no child is left behind in the fight against vaccine-preventable diseases, particularly polio, and for reaching those in hard-to-reach areas or those who have missed vaccinations due to various barriers. Distributed by APO Group on behalf of World Health Organization (WHO) - Ethiopia.
