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Bulletin of the World Health... Dec 2023A decrease in vaccine coverage in conflict-affected areas has placed Yemen at higher risk of polio outbreaks caused by vaccine-derived poliovirus strains.
PROBLEM
A decrease in vaccine coverage in conflict-affected areas has placed Yemen at higher risk of polio outbreaks caused by vaccine-derived poliovirus strains.
APPROACH
In response to polio outbreaks, the Yemeni health ministry and partners initiated multiple vaccination campaigns to deliver vaccines to children. We also implemented several measures to enhance communication, education, health promotion and hygiene, especially in camps for internally displaced people.
LOCAL SETTING
In 2009, Yemen achieved polio-free status and maintained it until 2019. However, the ongoing political conflict since 2015, coupled with challenges in delivering the polio vaccine to conflict-affected areas, resulted in two polio outbreaks: 35 cases caused by vaccine-derived poliovirus strain 1 between 2019 and 2021, and 230 cases due to vaccine-derived poliovirus strain 2 between November 2021 and December 2022.
RELEVANT CHANGES
In response to the first outbreak, by the end of 2020, we vaccinated 7.2 million children through nationwide vaccination campaigns, except in Sa'ada governorate due to a ban by the authorities. By the end of 2021, 3 800 313 children younger than 5 years had received polio vaccines. For the second outbreak, by the end of 2022, 4 463 389 vaccines had been given to children younger than 10 years, and 1 217 423 to those younger than 5 years.
LESSONS LEARNT
Vaccination campaigns in conflict-affected areas with low vaccine coverage remain crucial in eradicating polio. Efforts are needed to reach vulnerable groups such as displaced populations. Advocacy, communication and social mobilization actions help ensure broader public inclusion and participation in vaccination efforts to prevent polio outbreaks.
Topics: Child; Humans; Yemen; Poliomyelitis; Poliovirus; Poliovirus Vaccines; Disease Outbreaks
PubMed: 38024246
DOI: 10.2471/BLT.23.290122 -
Human Vaccines & Immunotherapeutics Dec 2023Poliomyelitis is an acute infectious disease caused by poliovirus. This bibliometric analysis aims to examine the status of poliomyelitis research in the past... (Review)
Review
Poliomyelitis is an acute infectious disease caused by poliovirus. This bibliometric analysis aims to examine the status of poliomyelitis research in the past 20 years. Information regarding polio research was obtained from the Web of Science Core Collection database. CiteSpace, VOSviewer, and Excel were used to perform visual and bibliometric analysis with respect to countries/regions, institutions, authors, journals and keywords. A total of 5,335 publications on poliomyelitis were published from 2002 to 2021. The USA was the county with the majority of publications. Additionally, the most productive institution was the Centers for Disease Control and Prevention. Sutter, RW produced the most papers and had the most co-citations. was the journal with the most polio-related publications and citations. The most common keywords were mainly about polio immunology research ("polio," "immunization," "children," "eradication" and "vaccine"). Our study is helpful for identifying research hotspots and providing direction for future research on poliomyelitis.
Topics: United States; Child; Humans; Poliomyelitis; Bibliometrics; Poliovirus; Centers for Disease Control and Prevention, U.S.; Databases, Factual
PubMed: 36803526
DOI: 10.1080/21645515.2023.2173905 -
Pathogens (Basel, Switzerland) Feb 2024The Global Polio Eradication Initiative made immense progress after its establishment in 1988 as a consequence of high coverage with various poliovirus vaccines in all... (Review)
Review
The Global Polio Eradication Initiative made immense progress after its establishment in 1988 as a consequence of high coverage with various poliovirus vaccines in all populations of the world. Problems have arisen in recent years, however, related to security issues in some countries, to the circulation of vaccine-derived polioviruses, and to the recognition that individuals with certain immune deficiencies can remain infected and infectious for many months or years. As natural infection and different vaccines have different effects on the immune system, the patterns of humoral and mucosal immunity to polioviruses in the world today are complex but are crucial to the ultimate success of the eradication initiative. This paper describes the background of the current situation and current immunological patterns and discusses their implications for managing population immunity to polioviruses in the years ahead.
PubMed: 38535527
DOI: 10.3390/pathogens13030183 -
MMWR. Morbidity and Mortality Weekly... Jul 2023This report describes the status of introductions globally for eight World Health Organization (WHO)-recommended new and underutilized vaccines, comprising 10 individual...
This report describes the status of introductions globally for eight World Health Organization (WHO)-recommended new and underutilized vaccines, comprising 10 individual vaccine antigens. By 2021, among 194 countries worldwide, 33 (17%) provided all of these 10 WHO-recommended antigens as part of their routine immunization schedules; only one low-income country had introduced all of these recommended vaccines. Universal hepatitis B birth dose; human papillomavirus vaccine; rotavirus vaccine; and diphtheria, tetanus, and pertussis-containing vaccine first booster dose have been introduced by 57%, 59%, 60%, and 72% of all countries worldwide, respectively. Pneumococcal conjugate vaccine, rubella-containing vaccine, measles-containing vaccine second dose, and Haemophilus influenzae type b vaccine have been introduced by 78%, 89%, 94%, and 99% of all countries, respectively. The annual rate of new vaccine introductions declined precipitously when the COVID-19 pandemic started, from 48 in 2019 to 15 in 2020 before rising to 26 in 2021. Increased efforts to accelerate new and underutilized vaccine introductions are urgently needed to improve universal equitable access to all recommended vaccines to achieve the global Immunization Agenda 2021-2030 (IA2030) targets.
Topics: Humans; Infant; Diphtheria-Tetanus-Pertussis Vaccine; Pandemics; Haemophilus Vaccines; COVID-19; Vaccination; Measles Vaccine; Rubella Vaccine; Immunization Schedule; Poliovirus Vaccine, Inactivated; Hepatitis B Vaccines; Vaccines, Combined
PubMed: 37410663
DOI: 10.15585/mmwr.mm7227a2 -
Nature Jul 2023Vaccination with Sabin, a live attenuated oral polio vaccine (OPV), results in robust intestinal and humoral immunity and has been key to controlling poliomyelitis. As...
Vaccination with Sabin, a live attenuated oral polio vaccine (OPV), results in robust intestinal and humoral immunity and has been key to controlling poliomyelitis. As with any RNA virus, OPV evolves rapidly to lose attenuating determinants critical to the reacquisition of virulence resulting in vaccine-derived, virulent poliovirus variants. Circulation of these variants within underimmunized populations leads to further evolution of circulating, vaccine-derived poliovirus with higher transmission capacity, representing a significant risk of polio re-emergence. A new type 2 OPV (nOPV2), with promising clinical data on genetic stability and immunogenicity, recently received authorization from the World Health Organization for use in response to circulating, vaccine-derived poliovirus outbreaks. Here we report the development of two additional live attenuated vaccine candidates against type 1 and 3 polioviruses. The candidates were generated by replacing the capsid coding region of nOPV2 with that from Sabin 1 or 3. These chimeric viruses show growth phenotypes similar to nOPV2 and immunogenicity comparable to their parental Sabin strains, but are more attenuated. Our experiments in mice and deep sequencing analysis confirmed that the candidates remain attenuated and preserve all the documented nOPV2 characteristics concerning genetic stability following accelerated virus evolution. Importantly, these vaccine candidates are highly immunogenic in mice as monovalent and multivalent formulations and may contribute to poliovirus eradication.
Topics: Animals; Mice; Disease Models, Animal; Poliomyelitis; Poliovirus; Poliovirus Vaccine, Oral; Vaccines, Attenuated; Disease Eradication
PubMed: 37316671
DOI: 10.1038/s41586-023-06212-3 -
PloS One 2024Polio eradication is a current and common strategy throughout the globe. The study of the newly introduced inactivated poliovirus vaccine provides a grasp on the current...
INTRODUCTION
Polio eradication is a current and common strategy throughout the globe. The study of the newly introduced inactivated poliovirus vaccine provides a grasp on the current status of immunization and identifies any disparities in the implementation of the vaccine throughout Ethiopia. Thus, this study aimed to demonstrate the spatial distribution, coverage, and determinants of inactivated poliovirus vaccine immunization in Ethiopia.
METHOD
Spatial distribution and determinants of inactivated poliovirus vaccine immunization in Ethiopia were conducted using Ethiopian mini-demographic and health survey 2019 data. A total of 2,056 weighted children aged 12 to 35 months were included in the analysis. The association between the outcome and explanatory variables was determined by commuting the adjusted odds ratio at a 95% confidence interval. The p-value of less than 0.05 was used to declare factors as significantly associated with the inactivated poliovirus vaccine immunization.
RESULT
The weighted national coverage of inactivated poliovirus vaccine immunization in Ethiopia was 51.58% at a 95% confidence interval (49.42, 53.74). While the rates of inactivated poliovirus vaccine immunization were observed to be greater in Addis Ababa, Tigiray, Amahara, and Benishangul Gumuz provinces and lower in the Somali, Afar, and SNNPR provinces of Ethiopia, Antenatal care follow-up, place of delivery, place of residence, and region were significantly associated with inactivated poliovirus immunization in Ethiopia.
CONCLUSION
The distribution of inactivated poliovirus immunization was spatially variable across Ethiopia. Only about half of the children aged twelve to thirty-five months received the inactivated poliovirus vaccine in the country. The factors, both at the individual and community level, were significantly associated with inactivated poliovirus immunization. Therefore, policies and strategies could benefit from considering antenatal care follow-up, place of delivery, place of residence, and region while implementing inactivated poliovirus vaccine immunization.
Topics: Humans; Ethiopia; Poliovirus Vaccine, Inactivated; Female; Infant; Poliomyelitis; Male; Child, Preschool; Vaccination Coverage; Vaccination; Immunization Programs; Immunization
PubMed: 38820454
DOI: 10.1371/journal.pone.0301933 -
Nature Microbiology Sep 2023Timely detection of outbreaks is needed for poliovirus eradication, but gold standard detection in the Democratic Republic of the Congo takes 30 days (median). Direct...
Timely detection of outbreaks is needed for poliovirus eradication, but gold standard detection in the Democratic Republic of the Congo takes 30 days (median). Direct molecular detection and nanopore sequencing (DDNS) of poliovirus in stool samples is a promising fast method. Here we report prospective testing of stool samples from suspected polio cases, and their contacts, in the Democratic Republic of the Congo between 10 August 2021 and 4 February 2022. DDNS detected polioviruses in 62/2,339 (2.7%) of samples, while gold standard combination of cell culture, quantitative PCR and Sanger sequencing detected polioviruses in 51/2,339 (2.2%) of the same samples. DDNS provided case confirmation in 7 days (median) in routine surveillance conditions. DDNS enabled confirmation of three serotype 2 circulating vaccine-derived poliovirus outbreaks 23 days (mean) earlier (range 6-30 days) than the gold standard method. The mean sequence similarity between sequences obtained by the two methods was 99.98%. Our data confirm the feasibility of implementing DDNS in a national poliovirus laboratory.
Topics: Poliovirus; Nanopore Sequencing; Polymerase Chain Reaction; Dansyl Compounds
PubMed: 37591995
DOI: 10.1038/s41564-023-01453-4