Thomas R. Kreil

Clinical evidence suggests that antibodies from reconvalescent donors (persons who have recovered from infection) may be effective in the treatment of Ebola virus infection. Administration of this treatment to Ebola virus–infected patients while preventing the transmission of other pathogenic viruses may be best accomplished by use of virus-inactivated reconvalescent plasma.

The testing for adventitious viruses is of critical importance during development and production of biological products. The recent emergence and ongoing development of broad virus detection methods calls for an evaluation of whether these methods can appropriately be implemented into current adventitious agent testing procedures. To assess the suitability of several broad virus detection methods, a comparative experimental study was conducted: four virus preparations, which were spiked at two different concentrations each into two different cell culture media, were sent to four investigators in a blinded fashion for analysis with broad virus detection methods such as polymerase chain reaction-electrospray ionization mass spectrometry (PCR-ESI/MS), microarray, and two approaches utilizing massively parallel sequencing. The results that were reported by the investigators revealed that all methods were able to identify the majority of samples correctly (mean 83%), with a surprisingly narrow range among the methods, that is, between 72% (PCR-ESI/MS) and 95% (microarray). In addition to the correct results, a variety of unexpected assignments were reported for a minority of samples, again with little variation regarding the methods used (range 20-45%), while false negatives were reported for 0-25% of the samples. Regarding assay sensitivity, the viruses were detected by all methods included in this study at concentrations of about 4-5 log10 quantitative PCR copies/mL, and probably with higher sensitivity in some cases. In summary, the broad virus detection methods investigated were shown to be suitable even for detection of relatively low virus concentrations. However, there is also some potential for the production of false-positive as well as false-negative assignments, which indicates the requirement for further improvements before these methods can be considered for routine use.

The role of virus filtration in assuring the safety of biopharmaceutical products has gained importance in recent years. This is due to the fundamental advantages of virus filtration, which conceptually can remove all pathogens as long as their size is larger than the biomolecule of commercial interest, while at the same time being neutral to the biological activity of biopharmaceutical compound(s). Major progress has been made in the development of adequate filtration membranes that can remove even smaller viruses, or possibly even all.Establishing down‐scaled models for virus clearance studies that are fully equivalent with respect to operating parameters at manufacturing scale is a continuing challenge. This is especially true for virus filtration procedures where virus clearance studies at small‐scale determine the operating parameters, which can be used at manufacturing scale. This has limited volume‐to‐filter‐area‐ratios, with significant impact on process economics.An advanced small‐scale model of virus filtration, which allows the investigation of the full complexity of these processes, is described here. It includes the automated monitoring and control of all process parameters, as well as an electronic data acquisition system, which is fully compliant with current regulatory requirements for electronic records in a pharmaceutical environment. Biotechnol. Bioeng. 2015;112: 633–637.

Neuraminidase-inhibiting (NAi) antibodies have been reported to be an independent correlate of protection from influenza disease, but the NAi antibody response to influenza vaccination has never been assessed in chronically ill or immunocompromised participants. Using an enzyme-linked lectin assay, we demonstrated that 2 immunizations with a Vero cell culture-derived, whole-virus H5N1 A/Vietnam vaccine induces NAi antibodies in 94.3% of chronically ill and 83.8% of immunocompromised participants. A booster with a heterologous A/Indonesia H5N1 vaccine induced comparable NAi antibody titers in both groups and resulted in 100% seropositivity. These data support prepandemic H5N1 vaccination strategies for these highly vulnerable risk groups.

Convalescent plasma and fractionated immunoglobulins have been suggested as prophylactic or therapeutic interventions during an influenza pandemic.

We demonstrate 2 month old, female B10.T(6R) are highly resistant to systemic infection with the KIM5 strain of Yersinia pestis, and that B10.T(6R) mice become susceptible to Y. pestis infection by 5 months of age. In this study, both young (2 month) and middle-aged (5-12 month) B10.T(6R) were infected with equal CFUs of Y. pestis. The LD₅₀ of young B10.T(6R) mice was ∼1.4 × 10⁴ CFU, while middle-aged B10.T(6R) mice exhibited an LD₅₀ of ∼60 CFU. An elevated bacterial burden was found in the spleens of middle-aged mice at 24 and 60 h and in the livers at 60 h postinfection. Immune cell infiltration was greater in the livers of resistant young mice as compared to middle-aged and the susceptible C57BL/6N strain of mice. Unlike susceptible mice, young B10.T(6R) mice did not develop necrotic lesions throughout the liver. Instead livers from young B10.T(6R) mice contained granulomatous-like structures. Immunohistochemical staining of liver sections from these mice at 60 h postinfection revealed that the majority of immune cells present in these structures consisted of neutrophils. These findings suggest that resistance to plague in B10.T(6R) mice correlates with early formation of neutrophilic lesions in the liver.

BACKGROUND: Chikungunya virus (CHIKV) outbreaks were previously restricted to parts of Africa, Indian Ocean Islands, South Asia, and Southeast Asia. In 2007, however, the first autochthonous CHIKV transmission was reported in Europe. High‐level viremia, a mosquito vector that is also present in large urban areas of Europe and America, and uncertainty around the resistance of this Alphavirus toward physiochemical inactivation processes raised concerns about the safety of plasma derivatives. To verify the safety margins of plasma products with respect to CHIKV, commonly used virus inactivation steps were investigated for their effectiveness to inactivate this newly emerging virus.STUDY DESIGN AND METHODS: Pasteurization for human serum albumin (HSA), vapor heating for Factor VIII inhibitor bypassing activity, solvent/detergent (S/D) treatment for intravenous immunoglobulin (IVIG), and incubation at low pH for IVIG were investigated for their capacity to inactivate CHIKV and the closely related Sindbis virus (SINV). The obtained results were compared to previous studies with West Nile virus and the commonly used model virus bovine viral diarrhea virus.RESULTS: The data generated demonstrate the effective inactivation of CHIKV as well as SINV by the inactivation steps investigated and thereby support results from earlier validation studies in which model viruses were used.CONCLUSION: High inactivation capacities with respect to CHIKV were demonstrated. This provides solid reassurance for the safety of plasma products and the results verify that the use of model viruses is appropriate to predict the inactivation characteristics of newly emerging viruses when their physicochemical properties are well characterized.