The attenuated phenotype of Sabin 3 poliovirus compared with its neurovirulent progenitor strain has been largely accounted for by mutations in the genome at positions 472 and 2034 (G. D. Westrop, K. A. Wareham, D. M. A. Evans, G. Dunn, P. D. Minor, D. I. Magrath, F. Taffs, S. Marsden, M. A. Skinner, G. C. Schild, and J. W. Almond, J. Virol. 63:1338-1344, 1989). By sequencing vaccine virus RNA, we recently identified another Sabin 3-specific mutation at position 2493 (U----C), which predicts an Ile----Thr change at the sixth residue of VP1 (C. Weeks-Levy, J. M. Tatem, S. J. DiMichele, W. Waterfield, A. F. Georgiu, and S. J. Mento, Virology 185:934-937, 1991). Viruses generated by using cDNAs which represent the vaccine sequence (LED3) and a derivative (VR318) possessing a single base change to the wild-type nucleotide (U) at 2493 were used to determine the impact of the 2493 mutation on virus phenotype. The VP1 proteins of LED3 and VR318 viruses were distinguishable by denaturing electrophoretic analysis. LED3 produced smaller plaques in Vero cells than VR318 virus did. Neurovirulence testing of these cDNA-derived viruses in monkeys demonstrated that the 2493 mutation in LED3 virus is attenuating.
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http://dx.doi.org/10.1128/JVI.66.5.3194-3197.1992 | DOI Listing |
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 PDFVaccines (Basel)
November 2024
Bill & Melinda Gates Foundation, Seattle, WA 98109, USA.
Although wild poliovirus type 2 has been eradicated, the prolonged transmission of the live- attenuated virus contained in the type-2 oral polio vaccine (OPV2) in under-immunized populations has led to the emergence of circulating vaccine-derived poliovirus type 2 (cVDPV2). The novel OPV2 (nOPV2) was designed to be more genetically stable and reduce the chance of cVDPV2 emergence while retaining comparable immunogenicity to the Sabin monovalent OPV2 (mOPV2). This study aimed to estimate the relative reduction in the emergence risk due to the use of nOPV2 instead of mOPV2.
View Article and Find Full Text PDFChina CDC Wkly
December 2024
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases (NITFID), National Immunization Programme, Chinese Center for Disease Control and Prevention, Beijing, China.
Introduction: Domestic Sabin-strain inactivated poliovirus vaccine (sIPV) was approved for use in China in 2015 and introduced into the national immunization schedule in a sequential schedule with oral poliovirus vaccine (OPV) in May 2016. However, a comprehensive analysis describing the characteristics, occurrences, and incidences of adverse events following immunization (AEFI) with sIPV in China is lacking.
Methods: Data on sIPV doses administered and AEFI reported from 2015 to 2022 were obtained from the Chinese National Immunization Information System (CNIIS).
J Appl Microbiol
January 2025
Department of Genetics, Microbiology and Statistics, School of Biology, Enteric Virus Laboratory, Barcelona 08028, Spain.
Enteroviruses (EVs) are a highly diverse group of viruses multiplying primarily in the gastrointestinal tract and/or the upper respiratory tract, initially distributed in two separate genera: Enterovirus and Rhinovirus, respectively. According to the similarities in genome organization and particle structure, rhinovirus species were later reclassified as also belonging to genus Enterovirus. Human EV infections are usually asymptomatic or causing mild clinical manifestations.
View Article and Find Full Text PDFViruses
November 2024
Department of Industrial Transformation, Institute of Medical Biology, Chinese Academy of Medical Sciences, Peking Union Medical College, Kunming 650000, China.
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