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A fundamental aspect of biological product safety is to assure absence of adventitious agents in the final product. Next-generation or high-throughput sequencing (NGS/HTS) has recently demonstrated detection of viruses that were previously missed using the recommended routine assays for adventitious agent testing of biological products. This meeting was co-organized by the International Alliance for Biological Standardization (IABS) and the U.S. Food and Drug Administration (FDA) to assess the current status and discuss the readiness of NGS for adventitious virus detection in biologics. The presentations included efforts for standardization, case studies on applications in biologics, comparison with routine virus detection assays, and current regulatory thinking. Participants identified the need for standard reference reagents, well-annotated databases, large data storage and transfer capacity, personnel with relevant expertise, particularly in bioinformatics; and harmonization of international regulations for testing biologic products and reagents used for their manufacturing. We hope this meeting summary will be of value to regulators and industry for considerations of NGS applications for adventitious virus detection in biologics., (Copyright © 2018.)

Bovine viral diarrhoea virus (BVDV) is a cattle pathogen that has previously been reported to be present in bovine raw materials used in the manufacture of biological products for human use. Seven lots of trivalent measles, mumps and rubella (MMR) vaccine and 1 lot of measles vaccine from the same manufacturer, together with 17 lots of foetal bovine serum (FBS) from different vendors, 4 lots of horse serum, 2 lots of bovine trypsin and 5 lots of porcine trypsin were analysed for BVDV using recently developed techniques, including PCR assays for BVDV detection, a qRT-PCR and immunofluorescence-based virus replication assays, and deep sequencing to identify and genotype BVDV genomes. All FBS lots and one lot of bovine-derived trypsin were PCR-positive for the presence of BVDV genome; in contrast all vaccine lots and the other samples were negative. qRT-PCR based virus replication assay and immunofluorescence-based infection assay detected no infectious BVDV in the PCR-positive samples. Complete BVDV genomes were generated from FBS samples by deep sequencing, and all were BVDV type 1. These data confirmed that BVDV nucleic acid may be present in bovine-derived raw materials, but no infectious virus or genomic RNA was detected in the final vaccine products., (Copyright © 2018 International Alliance for Biological Standardization. All rights reserved.)

When poliomyelitis is totally eradicated from the natural world containment will be vital to prevent its re-emergence. The matter has become pressing as type 2 component of oral polio vaccine was completely withdrawn by May 2016 as wild ty[e 2 was declared eradicated. Work on polioviruses must be contained in accordance with GAPIII (the third version of the Global Action Plan of WHO). Some activities will be essential for years after eradication. Vaccine production and control, surveillance and supportive applied and academic research must all continue. Most laboratories do not currently comply with GAPIII and could not do so in the short term without disruption of essential activities including vaccine supply. The development and use of safer strains is raised in GAPIII and the meeting considered the strains available and the uses to which they could be put to facilitate compliance with the aims of GAPIII., (Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.)

Nucleic acid amplification techniques (NAT) are routinely used for clinical diagnostics and monitoring hepatitis B virus (HBV) infections, and are implemented on a voluntary basis for blood screening. A collaborative study was performed to evaluate a replacement WHO International Standard for HBV for the standardization of NAT. Two lyophilised HBV candidates were evaluated by 16 laboratories worldwide, alongside the existing HBV International Standard. The overall mean potency estimates for the candidate samples 1 and 2, relative to sample 3 (2nd HBV International Standard), from quantitative assays, were 5.93 and 5.98 log 10 International Units (IU)/mL respectively. The variability in individual laboratory mean estimates for samples 1-3 for quantitative assays was ∼0.3 log 10 IU/mL. The inter-laboratory variability for qualitative assays was higher. Accelerated thermal degradation studies indicate that both lyophilised candidates are stable and suitable for long-term use. Overall, the results suggested that both candidates were suitable as replacement International Standards. Sample 1 (NIBSC code 10/264) was established as the 3rd WHO International Standard for HBV for NAT with an assigned potency of 850,000 IU/mL (∼5.93 log 10 IU/mL), when reconstituted in 0.5 mL of nuclease-free water. It is intended for the calibration (in IU) of secondary reference materials used in HBV NAT., (Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Variability in viral load measurements using nucleic acid amplification techniques (NAT) has a significant impact on the management of Epstein-Barr virus (EBV)-associated diseases, and has highlighted a need for standardisation of these measurements. The aim of this collaborative study was to evaluate the suitability of a range of candidate reference materials to harmonise EBV viral load measurements in a wide range of NAT assays. Candidate materials included lyophilised and liquid whole virus preparations of the EBV B95-8 strain, and preparations of Namalwa and Raji cells. Variability between the individual laboratory mean estimates for each candidate was 2.5 log10 copies/mL. The agreement between laboratories was improved when the potency of each candidate was expressed relative to the lyophilised B95-8 preparation. The results of the study indicate the suitability of this candidate as the 1st WHO International Standard for EBV for NAT. It was established in October 2011 by the WHO's Expert Committee on Biological Standardisation with an assigned potency of 5 × 10(6) International Units (IU) (NIBSC code 09/260). It is intended to be used for the calibration of secondary reference materials, used in EBV NAT assays, in IU, thereby improving the comparability of patient viral load measurements., (Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Variability in the performance of nucleic acid amplification technology (NAT)-based assays presents a significant problem in the diagnosis and management of human cytomegalovirus (HCMV) infections. Here we describe a collaborative study to evaluate the suitability of candidate reference materials to harmonize HCMV viral load measurements in a wide range of NAT assays. Candidate materials comprised lyophilized Merlin virus, liquid Merlin virus, liquid AD169 virus, and purified HCMV Merlin DNA cloned into a bacterial artificial chromosome. Variability in the laboratory mean HCMV concentrations determined for virus samples across the different assays was 2 log10. Variability for the purified DNA sample was higher (>3 log10). The agreement between laboratories was markedly improved when the potencies of the liquid virus samples were expressed relative to the lyophilized virus candidate. In contrast, the agreement between laboratories for the purified DNA sample was not improved. Results indicated the suitability of the lyophilized Merlin virus preparation as the 1st WHO International Standard for HCMV for NAT. It was established in October 2010, with an assigned potency of 5 × 10(6) International Units (IU) (NIBSC code 09/162). It is intended to be used to calibrate secondary references, used in HCMV NAT assays, in IU., (Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Each year the production of seasonal influenza vaccines requires antigen standards to be available for the potency assessment of vaccine batches. These are calibrated and assigned a value for haemagglutinin (HA) content. The calibration of an antigen standard is carried out in a collaborative study amongst a small number of national regulatory laboratories which are designated by WHO as Essential Regulatory Laboratories (ERLs) for the purposes of influenza vaccine standardisation. The calibration involves two steps; first the determination of HA protein in a primary liquid standard by measurement of total protein in a purified influenza virus preparation followed by determination of the proportion of HA as determined by PAGE analysis of the sample; and second, the calibration of the freeze-dried reference antigen against the primary standard by single radial immunodiffusion (SRD) assay. Here we describe a collaborative study to assess the effect of adding a deglycosylation step prior to the SDS-PAGE analysis for the assessment of relative HA content. We found that while the final agreed HA value of the samples tested was not significantly different with or without deglycosylation, the deglycosylation step greatly improved between-laboratory agreement., (Copyright © 2012 The International Alliance for Biological Standardization. All rights reserved.)

The results of tests of the neurovirulence of three yellow fever vaccine preparations of different lineages are presented. Two preparations that have been used to make vaccines of acceptable safety and efficacy gave very similar results. A third preparation from the Robert Koch Institute, designated 168-73, was proposed as a reference preparation for the mouse potency assay in 1985 by WHO, but has been more often used as a reference in the monkey neurovirulence test. In the test described here 168-73 was of lower virulence than either of the other two preparations., (Copyright © 2011 The International Association for Biologicals. Published by Elsevier Ltd. All rights reserved.)

In the 1950s the use of primary rhesus macaque kidney cultures to propagate poliovirus for vaccine production led to the contamination of vaccines with simian virus 40 (SV40). African green monkey kidney (AGMK) cultures free of SV40 were used as an alternative cell substrate for vaccine manufacture. In this study we evaluate oral poliovirus seeds, vaccine bulks and vaccines themselves for the presence of a common contaminant of AGMK cultures, simian cytomegalovirus (SCMV). Using sensitive polymerase chain reaction (PCR) techniques, nearly half of the samples analysed were found to be contaminated with SCMV sequences. However, vaccine bulks, positive by PCR for SCMV failed to show any evidence of infectious virus in these studies. One poliovirus vaccine and one seed, propagated on rhesus macaque kidney cultures were found to be positive for the rhesus monkey CMV by PCR.