A chimaeric poliovirus carrying a type-2-specific neutralization epitope on a type 1 capsid was created by site-directed mutagenesis of the Mahoney strain of poliovirus type 1. An EcoRV and a HindIII restriction sites were first constructed in the cDNA of poliovirus type 1 at nucleotide positions 2756 and 2786, respectively, i.e. on either side of the sequence encoding neutralization epitope C3 (VP1 amino acids 93-103), which is part of neutralization site NImI. The cDNA sequence framed by the two sites was next taken out and replaced by custom-made oligonucleotides encoding the equivalent region of VP1 from the Lansing strain of poliovirus type 2. The DNA from the plasmid carrying such a hybrid construct was transfected onto CV1 cells generating a chimaeric virus, v510. Neutralization of v510 with a panel of monoclonal antibodies showed that v510 has lost the poliovirus type 1 C3 epitope but acquired a new, poliovirus type-2-specific neutralization epitope. Preliminary results indicate that v510 also shows neurovirulence for mice, which is a specific trait of the Lansing strain of poliovirus type 2.
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http://dx.doi.org/10.1016/s0769-2617(88)80008-x | DOI Listing |
Int J Nanomedicine
January 2025
School of Basic Medicine, Ningxia Medical University, Yinchuan, People's Republic of China.
Background: Colorectal cancer (CRC) is a highly malignant and aggressive gastrointestinal tumor. Due to its weak immunogenicity and limited immune, cell infiltration lead to ineffective clinical outcomes. Therefore, to improve the current prophylaxis and treatment scheme, offering a favorable strategy efficient against CRC is urgently needed.
View Article and Find Full Text PDFJ Infect Dis
January 2025
School of Public Health, Medical Research Council Centre for Global Infectious Disease Analysis, Imperial College London, London, United Kingdom.
Background: Between 2016 and 2023, 3248 cases of circulating vaccine-derived type 2 poliomyelitis (cVDPV2) were reported globally and supplementary immunization activities (SIAs) with monovalent type 2 oral poliovirus vaccine (mOPV2) and novel type 2 oral poliovirus vaccine (nOPV2) targeted an estimated 356 and 525 million children, respectively. This analysis estimates the community-level impact of nOPV2 relative to mOPV2 SIAs.
Methods: We fitted interrupted time-series regressions to surveillance data between January 2016 and November 2023 to estimate the impact of nOPV2 and mOPV2 SIAs on cVDPV2 poliomyelitis incidence and prevalence in environmental surveillance across 37 countries, directly comparing the impact of SIAs in 13 countries where both vaccines were used.
Vaccines (Basel)
January 2025
Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, MD 20993, USA.
Background/objectives: Conventional live oral poliovirus vaccines (OPVs) effectively prevent poliomyelitis. These vaccines are derived from three attenuated Sabin strains of poliovirus, which can revert within the first week of replication to a neurovirulent phenotype, leading to sporadic cases of vaccine-associated paralytic poliomyelitis (VAPP) among vaccinees and their contacts. A novel OPV2 vaccine (nOPV2) with enhanced genetic stability was developed recently; type 1 and type 3 nOPV strains were engineered using the nOPV2 genome as a backbone by replacing the capsid precursor polyprotein (P1) with that of Sabin strains type 1 and type 3, respectively.
View Article and Find Full Text PDFEuro Surveill
January 2025
Medicines and Healthcare products Regulatory Agency (MHRA), South Mimms (Potters Bar), United Kingdom.
In 2024, circulating vaccine-derived poliovirus type 2 (cVDPV2) was detected in wastewater samples in Finland, Germany, Poland, Spain and the United Kingdom (UK). All strains were genetically linked, but sequence analysis showed high genetic diversity among the strains identified within individual wastewater sites and countries and an unexpected high genetic proximity among isolates from different countries. Taken together these results, with sequential samples having tested positive in various sites, a broader geographic distribution beyond positive sampling sites must be considered.
View Article and Find Full Text PDFLancet Infect Dis
January 2025
WHO, Conakry, Guinea.
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