The authors resume a several years' experience of potency testing inactivated polio vaccines with an in vivo-vitro assay based on inoculation of 3 week-old chicken and measure of neutralizing antibodies at 5 days on Hep 2 cells in a microplate system. Critical points, specificity and reproducibility are successively outlined. Preliminary combining results with determination of D-antigen by ELISA method and human immunization are submitted in view of a future standardization.
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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)
January 2025
Laboratory of Tick-Borne Encephalitis and Other Viral Encephalitides, Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of RAS (Institute of Poliomyelitis), Moscow 108819, Russia.
: We evaluate the immunotherapeutic potential of the yellow fever virus vaccine strain 17D (YFV 17D) for intratumoral therapy of pancreatic cancer in mice. : The cytopathic effect of YFV 17D on mouse syngeneic pancreatic cancers cells were studied both in vitro and in vivo and on human pancreatic cancers cells in vitro. : YFV 17D demonstrated a strong cytopathic effect against human cancer cells in vitro.
View Article and Find Full Text PDFZhonghua Yu Fang Yi Xue Za Zhi
January 2025
Immunization Program Institute of Shaanxi Provincial Center for Disease Control and Prevention, Xi'an 710054, China.
To investigate the safety of the tetravalent meningococcal conjugate vaccine (MPCV-ACYW) in combination with the inactivated poliomyelitis (IPV) vaccine and diphtheria-tetanus-acellular pertussis (DTaP) vaccine for infants aged 3-5 months and provide real-world evidence for the immunization strategy of vaccine combination. From June to October 2023, a total of 600 3-month-old infants were selected and divided into three groups: control group, mono-vaccination group and combined vaccination group. They were simultaneously or individually vaccinated with MPCV-ACYW, IPV and DTaP vaccines at 3, 4, and 5 months of age, 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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