Publications by authors named "Jens-Peter Gregersen"

Looking for a robust and simple method to replace formaldehyde fumigation for the disinfection of virus-handling laboratories and facilities, we tested peracetic acid fogging as a method to inactivate stable viruses under practical conditions. Peracetic acid/hydrogen peroxide (5.8%/27.

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CONFERENCE PROCEEDING Proceedings of the PDA/FDA Adventitious Viruses in Biologics: Detection and Mitigation Strategies Workshop in Bethesda, MD, USA; December 1-3, 2010 Guest Editors: Arifa Khan (Bethesda, MD), Patricia Hughes (Bethesda, MD) and Michael Wiebe (San Francisco, CA) For decades conventional tests in cell cultures and in laboratory animals have served as standard methods for broad-spectrum screening for adventitious viruses. New virus detection methods based on molecular biology have broadened and improved our knowledge about potential contaminating viruses and about the suitability of the conventional test methods. This paper summarizes and discusses practical aspects of conventional test schemes, such as detectability of various viruses, questionable or false-positive results, animal numbers needed, time and cost of testing, and applicability for rapidly changing starting materials.

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This paper summarizes results obtained by multiplex PCR screening of human clinical samples for respiratory viruses and corresponding data obtained after passaging of virus-positive samples in MDCK 33016PF cells. Using the ResPlexII v2.0 (Qiagen) multiplex PCR, 393 positive results were obtained in 468 clinical samples collected during an influenza season in Germany.

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After more than 60 years, the conventional production of influenza vaccines employing fertilized chicken eggs has reached its limits - both in terms of temporal flexibility and vaccine production volume. This problem is compounded by the fact that the pandemic-driven situation in 2009 has roughly doubled the overall vaccine demand. Modern cell culture technology has significant advantages over the conventional method of manufacturing influenza vaccines employing embryonated chicken eggs, and enables manufacturers to respond rapidly to the increasing worldwide seasonal and pandemic-driven need for influenza vaccines.

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Prions are pathogenic proteins and are the cause for spongiform encephalopathies. Pathogenic prions differ from physiologically common non-pathogenic prions only in their sterical structure. Upon infection by a pathogenic prion protein, a series of reactions is initiated in which common non-pathogenic prion proteins are transformed into pathogenic prions.

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Cell culture-based production methods may assist in meeting increasing demand for seasonal influenza vaccines and developing production flexibility required for addressing influenza pandemics. MDCK-33016PF cells are used in propagation of a cell-based seasonal influenza vaccine (Optaflu); but, like most continuous cell lines, can grow in immunocompromised mice to produce tumors. It is, therefore, essential that no residual cells remain within the vaccine, that cell lysates or DNA are not oncogenic, and that the cell substrate does not contain oncogenic viruses or oncogenic DNA.

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After more than 60 years, the conventional production of influenza vaccines employing fertilized chicken eggs has reached its limits - both in terms of temporal flexibility and vaccine production volume. This situation is compounded by the fact that the present pandemic-driven situation has roughly doubled the overall vaccine demand virtually "overnight". Modem cell culture technology has significant advantages over the conventional method of manufacturing influenza vaccines employing embryonated chicken eggs, and enables manufacturers to respond rapidly to the exploding worldwide seasonal and pandemic-driven need for influenza vaccines.

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A risk-assessment model has demonstrated the ability of a new cell culture-based vaccine manufacturing process to reduce the level of any adventitious agent to a million-fold below infectious levels. The cell culture-derived subunit influenza vaccine (OPTAFLU), Novartis Vaccines and Diagnostics) is produced using Madin-Darby canine kidney (MDCK) cells to propagate seasonal viral strains, as an alternative to embryonated chicken-eggs. As only a limited range of mammalian viruses can grow in MDCK cells, similar to embryonated eggs, MDCK cells can act as an effective filter for a wide range of adventitious agents that might be introduced during vaccine production.

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Influenza vaccine production has traditionally relied on the use of embryonated chicken eggs for virus isolation and propagation, but recently, cell-culture-derived manufacturing methods have been introduced. During influenza vaccine production, by either conventional or cell culture methods, there is a risk of incidental contamination by adventitious agents. Thus, a risk-assessment model has been developed to qualitatively assess the potential risk of vaccine process contamination by viral pathogens.

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