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Clinical Chemistry Sep 2020
Topics: Animals; COVID-19; Haplorhini; History, 20th Century; Humans; Pandemics; Poliomyelitis; Poliovirus; Poliovirus Vaccines; SARS-CoV-2
PubMed: 32870989
DOI: 10.1093/clinchem/hvaa155 -
Science (New York, N.Y.) Mar 2022Cases tumble in Pakistan and Afghanistan but African outbreaks now threaten eradication.
Cases tumble in Pakistan and Afghanistan but African outbreaks now threaten eradication.
Topics: Afghanistan; Africa; Disease Outbreaks; Humans; Immunization Programs; Pakistan; Poliomyelitis; Poliovirus; Poliovirus Vaccine, Oral
PubMed: 35271326
DOI: 10.1126/science.adb1920 -
Vaccine Apr 2023The global withdrawal of trivalent oral poliovirus vaccine (OPV) (tOPV, containing Sabin poliovirus strains serotypes 1, 2 and 3) from routine immunization, and the...
BACKGROUND
The global withdrawal of trivalent oral poliovirus vaccine (OPV) (tOPV, containing Sabin poliovirus strains serotypes 1, 2 and 3) from routine immunization, and the introduction of bivalent OPV (bOPV, containing Sabin poliovirus strains serotypes 1 and 3) and trivalent inactivated poliovirus vaccine (IPV) into routine immunization was expected to improve population serologic and mucosal immunity to types 1 and 3 poliovirus, while population mucosal immunity to type 2 poliovirus would decline. However, over the period since tOPV withdrawal, the implementation of preventive bOPV supplementary immunization activities (SIAs) has decreased, while outbreaks of type 2 circulating vaccine derived poliovirus (cVDPV2) have required targeted use of monovalent type 2 OPV (mOPV2).
METHODS
We develop a dynamic model of OPV-induced immunity to estimate serotype-specific, district-level immunity for countries in priority regions and characterize changes in immunity since 2016. We account for the changes in routine immunization schedules and varying implementation of preventive and outbreak response SIAs, assuming homogenous coverages of 50% and 80% for SIAs.
RESULTS
In areas with strong routine immunization, the switch from tOPV to bOPV has likely resulted in gains in population immunity to types 1 and 3 poliovirus. However, we estimate that improved immunogenicity of new schedules has not compensated for declines in preventive SIAs in areas with weak routine immunization. For type 2 poliovirus, without tOPV in routine immunization or SIAs, mucosal immunity has declined nearly everywhere, while use of mOPV2 has created highly heterogeneous population immunity for which it is important to take into account when responding to cVDPV2 outbreaks.
CONCLUSIONS
The withdrawal of tOPV and declining allocations of resources for preventive bOPV SIAs have resulted in reduced immunity in vulnerable areas to types 1 and 3 poliovirus and generally reduced immunity to type 2 poliovirus in the regions studied, assuming homogeneous coverages of 50% and 80% for SIAs. The very low mucosal immunity to type 2 poliovirus generates substantially greater risk for further spread of cVDPV2 outbreaks. Emerging gaps in immunity to all serotypes will require judicious targeting of limited resources to the most vulnerable populations by the Global Polio Eradication Initiative (GPEI).
Topics: Humans; Poliovirus; Poliovirus Vaccine, Oral; Poliomyelitis; Serogroup; Vaccination; Poliovirus Vaccine, Inactivated
PubMed: 35339308
DOI: 10.1016/j.vaccine.2022.03.013 -
International Journal of Molecular... Dec 2022The phenomenon of internal initiation of translation was discovered in 1988 on poliovirus mRNA. The prototypic -acting element in the 5' untranslated region (5'UTR) of... (Review)
Review
The phenomenon of internal initiation of translation was discovered in 1988 on poliovirus mRNA. The prototypic -acting element in the 5' untranslated region (5'UTR) of poliovirus mRNA, which is able to direct initiation at an internal start codon without the involvement of a cap structure, has been called an IRES (Internal Ribosome Entry Site or Segment). Despite its early discovery, poliovirus and other related IRES elements of type I are poorly characterized, and it is not yet clear which host proteins (a.k.a. IRES trans-acting factors, ITAFs) are required for their full activity in vivo. Here we discuss recent and old results devoted to type I IRESes and provide evidence that Poly(rC) binding protein 2 (PCBP2), Glycyl-tRNA synthetase (GARS), and Cold Shock Domain Containing E1 (CSDE1, also known as UNR) are major regulators of type I IRES activity.
Topics: Poliovirus; Internal Ribosome Entry Sites; Trans-Activators; Regulatory Sequences, Nucleic Acid; Codon, Initiator; RNA, Messenger; Protein Biosynthesis; 5' Untranslated Regions; RNA, Viral
PubMed: 36555135
DOI: 10.3390/ijms232415497 -
Emerging Infectious Diseases Feb 2021Since May 2019, the Central African Republic has experienced a poliomyelitis outbreak caused by type 2 vaccine-derived polioviruses (VDPV-2s). The outbreak affected...
Since May 2019, the Central African Republic has experienced a poliomyelitis outbreak caused by type 2 vaccine-derived polioviruses (VDPV-2s). The outbreak affected Bangui, the capital city, and 10 districts across the country. The outbreak resulted from several independent emergence events of VDPV-2s featuring recombinant genomes with complex mosaic genomes. The low number of mutations (<20) in the viral capsid protein 1-encoding region compared with the vaccine strain suggests that VDPV-2 had been circulating for a relatively short time (probably <3 years) before being isolated. Environmental surveillance, which relies on a limited number of sampling sites in the Central African Republic and does not cover the whole country, failed to detect the circulation of VDPV-2s before some had induced poliomyelitis in children.
Topics: Central African Republic; Child; Disease Outbreaks; Humans; Poliomyelitis; Poliovirus; Poliovirus Vaccine, Oral
PubMed: 33496226
DOI: 10.3201/eid2702.203173 -
Current Opinion in Neurology Jun 2023Recent outbreaks of poliomyelitis in countries that have been free of cases for decades highlight the challenges of eradicating polio in a globalized interconnected... (Review)
Review
PURPOSE OF REVIEW
Recent outbreaks of poliomyelitis in countries that have been free of cases for decades highlight the challenges of eradicating polio in a globalized interconnected world beset with a novel viral pandemic. We provide an epidemiological update, advancements in vaccines, and amendments in public health strategy of poliomyelitis in this review.
RECENT FINDINGS
Last year, new cases of wild poliovirus type 1 (WPV1) were documented in regions previously documented to have eradicated WPV1 and reports of circulating vaccine-derived poliovirus type 2 (cVDPV2) and 3 (cVDPV3) in New York and Jerusalem made international headlines. Sequencing of wastewater samples from environmental surveillance revealed that the WPV1 strains were related to WPV1 lineages from endemic countries and the cVDPV2 strains from New York and Jerusalem were not only related to each other but also to environmental isolates found in London. The evidence of importation of WPV1 cases from endemic countries, and global transmission of cVDPVs justifies renewed efforts in routine vaccination programs and outbreak control measures that were interrupted by the COVID-19 pandemic. After the novel oral poliovirus vaccine type 2 (nOPV2) received emergency authorization for containment of cVDPV2 outbreaks in 2021, subsequent reduced incidence, transmission rates, and vaccine adverse events, alongside increased genetic stability of viral isolates substantiates the safety and efficacy of nOPV2. The nOPV1 and nOPV3 vaccines, against type 1 and 3 cVDPVs, and measures to increase accessibility and efficacy of inactivated poliovirus vaccine (IPV) are in development.
SUMMARY
A revised strategy utilizing more genetically stable vaccine formulations, with uninterrupted vaccination programs and continued active surveillance optimizes the prospect of global poliomyelitis eradication.
Topics: Humans; Poliovirus; Pandemics; COVID-19; Poliovirus Vaccine, Oral; Poliomyelitis; Disease Outbreaks
PubMed: 37078665
DOI: 10.1097/WCO.0000000000001156 -
QJM : Monthly Journal of the... Jul 2021Medical advances of great importance in improving diagnosis, treatment or prevention of disease are often called 'breakthroughs'. The processes by which breakthroughs...
Medical advances of great importance in improving diagnosis, treatment or prevention of disease are often called 'breakthroughs'. The processes by which breakthroughs are achieved are multiple, but may include necessity (a problem which must be solved), opportunity (the time must be right), chance (the unexpected), curiosity (a desire to understand mechanisms) and ingenuity (ability to find a solution). Discovery can be the start of a chain reaction, so that the breakthrough at the end of the chain becomes "inevitable". Two examples are given in which these attributes played a part (i) the development of a vaccine against the poliomyelitis virus and (ii) the harnessing of penicillin as a therapeutic agent to treat serious bacterial infections.
Topics: Bacterial Infections; Humans; Penicillins; Poliomyelitis; Poliovirus; Vaccines
PubMed: 32840628
DOI: 10.1093/qjmed/hcaa257 -
PLoS Pathogens Sep 2021During replication, RNA viruses accumulate genome alterations, such as mutations and deletions. The interactions between individual variants can determine the fitness of...
During replication, RNA viruses accumulate genome alterations, such as mutations and deletions. The interactions between individual variants can determine the fitness of the virus population and, thus, the outcome of infection. To investigate the effects of defective interfering genomes (DI) on wild-type (WT) poliovirus replication, we developed an ordinary differential equation model, which enables exploring the parameter space of the WT and DI competition. We also experimentally examined virus and DI replication kinetics during co-infection, and used these data to infer model parameters. Our model identifies, and our experimental measurements confirm, that the efficiencies of DI genome replication and encapsidation are two most critical parameters determining the outcome of WT replication. However, an equilibrium can be established which enables WT to replicate, albeit to reduced levels.
Topics: Coinfection; Defective Viruses; Humans; Models, Theoretical; Poliovirus; Virus Replication
PubMed: 34570820
DOI: 10.1371/journal.ppat.1009277 -
Journal of Immunological Methods May 2022Next generation poliovirus vaccines are critical to reaching global poliovirus eradication goals. Recent efforts have focused on creating inactivated vaccines using...
Next generation poliovirus vaccines are critical to reaching global poliovirus eradication goals. Recent efforts have focused on creating inactivated vaccines using attenuated Sabin strains that maintain patient safety benefits and immunogenicity of conventional inactivated vaccines while increasing manufacturing safety and lowering production costs, and on developing novel oral vaccines using modified Sabin strains that provide critical mucosal immunity but are further attenuated to minimize risk of reversion to neurovirulence. In addition, there is a push to improve the analytical tools for poliovirus vaccine characterization. Conventional and Sabin inactivated poliovirus vaccines typically rely on standard plate-based ELISA as in vitro D-antigen potency assays in combination with WHO international standards as calibrants. While widely utilized, the current D-antigen ELISA assays have a long time to result (up to 72 h), can suffer from lab-to-lab inconsistency due to non-standardized protocols and reagents, and are inherently singleplex. For D-antigen quantitation, we have developed the VaxArray Polio Assay Kit, a multiplexed, microarray-based immunoassay that uses poliovirus-specific human monoclonal antibodies currently under consideration as standardized reagents for characterizing inactivated Sabin and Salk vaccines. The VaxArray assay can simultaneously quantify all 3 poliovirus serotypes with a time to result of less than 3 h. Here we demonstrate that the assay has limits of quantification suitable for both bioprocess samples and final vaccines, excellent reproducibility and precision, and improved accuracy over an analogous plate-based ELISA. The assay is suitable for adjuvanted combination vaccines, as common vaccine additives and crude matrices do not interfere with quantification, and is intended as a high throughput, standardized quantitation tool to aid inactivated poliovirus vaccine manufacturers in streamlining vaccine development and manufacturing, aiding the global polio eradication effort.
Topics: Antibodies, Viral; Antigens, Viral; Enzyme-Linked Immunosorbent Assay; Humans; Poliomyelitis; Poliovirus; Poliovirus Vaccine, Inactivated; Poliovirus Vaccine, Oral; Reproducibility of Results; Vaccines, Inactivated
PubMed: 35314144
DOI: 10.1016/j.jim.2022.113259 -
BMJ (Clinical Research Ed.) Jul 2023
Topics: Humans; Pandemics; Poliomyelitis; Poliovirus
PubMed: 37468140
DOI: 10.1136/bmj.p1605