Comparable virus inactivation by bovine or vegetable derived Tween 80 during solvent/detergent treatment

Assessing infectivity of emerging enveloped viruses in wastewater and sewage sludge: Relevance and procedures

The emergence of SARS-CoV-2 has heightened the need to evaluate the detection of enveloped viruses in the environment, particularly in wastewater, within the context of wastewater-based epidemiology. The studies published over the past 80 years focused primarily on non-enveloped viruses due to their ability to survive longer in environmental matrices such as wastewater or sludge compared to enveloped viruses. However, different enveloped viruses survive in the environment for different lengths of time. Therefore, it is crucial to be prepared to assess the potential infectious risk that may arise from future emerging enveloped viruses. This will require appropriate tools, notably suitable viral concentration methods that do not compromise virus infectivity. This review has a dual purpose: first, to gather all the available literature on the survival of infectious enveloped viruses, specifically at different pH and temperature conditions, and in contact with detergents; second, to select suitable concentration methods for evaluating the infectivity of these viruses in wastewater and sludge. The methodology used in this data collection review followed the systematic approach outlined in the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines. Concentration methods cited in the data gathered are more tailored towards detecting the enveloped viruses' genome. There is a lack of suitable methods for detecting infectious enveloped viruses in wastewater and sludge. Ultrafiltration, ultracentrifugation, and polyethylene glycol precipitation methods, under specific/defined conditions, appear to be relevant approaches. Further studies are necessary to validate reliable concentration methods for detecting infectious enveloped viruses. The choice of culture system is also crucial for detection sensitivity. The data also show that the survival of infectious enveloped viruses, though lower than that of non-enveloped ones, may enable environmental transmission. Experimental data on a wide range of enveloped viruses is required due to the variability in virus persistence in the environment.

Non-Compartment and compartmental pharmacokinetics, efficacy, and safety of Kedrion FIX concentrate

BACKGROUND

An open-label phase II, multicenter clinical trial was conducted at 11  Haemophilia Centres in  Italy, Romania, and Turkey, to evaluate the pharmacokinetics (PK), efficacy, and safety of high purity, plasma-derived, double virus inactivated and double nano-filtered factor IX (pd-FIX) concentrate (Kedrion FIX), EudraCT Number: 2005-006186-14.

MATERIAL AND METHODS

16 previously treated patients (PTPs) with severe or moderately severe haemophilia B were enrolled in the study. At enrolment, 14 underwent the first PK assessment (PK I), and the second PK (PK II) assessment was performed after six months of treatment (5 on-demand and nine prophylaxis) at the end of the study. PK parameters were evaluated by Non-Compartmental Analysis (NCA), One-Compartment model (OCM), and Two-Compartment Model (TCM). Efficacy of Kedrion FIX in all 16 patients was evaluated by the number of bleeding events, and clinical response following the infusions. Periodic FIX inhibitor assays and thrombogenicity tests were scheduled throughout the study to assess the safety of the drug.

RESULTS

As compared to the published data on PK of pdFIX, Kedrion FIX displayed a longer half-life (22.37-55.73 hrs), reduced clearance, and regular volume of distribution at PK I by both NCA and OCM. The comparison of outcomes of PK II with those of PK I by OCM,  also showed significant changes, particularly in patients on prophylaxis, who showed some improved parameters of PK. Due to two outlier values at the end of the trial, the NCA parameters of PK I were not compared to those of PK II. Breakthrough bleeds were successfully treated with 1 or 2 infusions. No significant adverse events were observed during the study.

DISCUSSION

During the six-month clinical study period, the use of Kedrion FIX resulted in a safe and effective pd-FIX concentrate with excellent PK characteristics.

Inactivation and Removal of Chikungunya Virus and Mayaro Virus from Plasma-derived Medicinal Products

Background: Chikungunya virus (CHIKV) and Mayaro virus (MAYV) are closely related members of the Semliki Forest complex within the genus alphavirus and are transmitted by arthropods, causing acute febrile illness in humans. CHIKV has spread to almost all continents, whereas autochthonous MAYV infections have been reported in South America and in the Caribbean. Nevertheless, there was concern about potential spread of MAYV to other regions similar to CHIKV in the past. The risk for transmission of emerging viruses by blood transfusion and the safety of plasma-derived medicinal products (PDMPs) are constant concerns. The manufacturing processes of PDMPs include procedures to inactivate/remove viruses. Methods: In this study, we investigated the reduction of MAYV and CHIKV by heat inactivation in various matrices, solvent/detergent treatment and nanofiltration. Results: Unexpectedly, MAYV was significantly more resistant to heat and solvent/detergent treatment compared to CHIKV. However, being similar in size, both MAYV and CHIKV were removed below the detection limit by 35 nm virus filters. Conclusions: The inactivation profiles of different alphavirus members vary considerably, even within the Semliki Forest Complex. However, robust dedicated viral inactivation/removal procedures commonly used in the plasma product industry are effective in inactivating or removing MAYV and CHIKV.

Reduction of the infectivity of baculovirus stocks frozen at ultra-low temperature in serum-free media: The role of lipid emulsions

The infectivity of stocks of baculoviruses produced in serum-free media is sensitive to freezing at ultra-low temperatures. The objective of this work was to elucidate the causes of such sensitivity, using as a model the freezing of stocks of Anticarsia gemmatalis multiple nucleopolyhedrovirus (AgMNPV), a baculovirus widely employed as biological insecticide. Titers of supernatants of cell cultures infected with AgMNPV in four different serum-free media supplemented with lipid emulsions were reduced by 50 to 90% after six months freezing. By using a full factorial experiment, freezing and lipid emulsion, as well as the interaction between them, were identified as the main factors reducing the viral titer. The virucidal effect of the lipid emulsion was reproduced by one of their components, the surfactant Polysorbate 80. Damaged viral envelopes were observed by transmission electron microscopy in most particles frozen in a medium supplemented with lipid emulsion or Polysorbate 80. Additionally, Polysorbate 80 also affected the infectivity of AgMNPV stocks that were incubated at 27°C. The identification of the roles played by the lipid emulsion and Polysorbate 80 is not only a contribution to the understanding of the mechanisms underlying the inactivation of baculovirus stocks produced in serum-free media during storage at ultra-low temperature, but is also an input for the rational development of new procedures aimed at improving both the preservation of baculovirus stocks and the composition of culture media for the production of baculovirus-based bioproducts in insect cells. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1559-1569, 2016.

Inactivation of enveloped and non-enveloped viruses in the process of chemical treatment and gamma irradiation of bovine-derived grafting materials

BACKGROUND

Xenografts, unlike other grafting products, cannot be commercialized unless they conform to stringent safety regulations. Particularly with bovine-derived materials, it is essential to remove viruses and inactivate infectious factors because of the possibility that raw materials are imbrued with infectious viruses. The removal of the characteristics of infectious viruses from the bovine bone grafting materials need to be proved and inactivation process should satisfy the management provision of the Food and Drug Administration (FDA). To date, while most virus inactivation studies were performed in human allograft tissues, there have been almost no studies on bovine bone.

METHODS

To evaluate the efficacy of virus inactivation after treatment of bovine bone with 70% ethanol, 4% sodium hydroxide, and gamma irradiation, we selected a variety of experimental model viruses that are known to be associated with bone pathogenesis, including bovine parvovirus (BPV), bovine herpes virus (BHV), bovine viral diarrhea virus (BVDV), and bovine parainfluenza-3 virus (BPIV-3). The cumulative virus log clearance factor or cumulative virus log reduction factor for the manufacturing process was obtained by calculating the sum of the individual virus log clearance factors or log reduction factors determined for individual process steps with different physicochemical methods.

RESULTS

The cumulative log clearance factors achieved by three different virus inactivation processes were as follows: BPV ≥ 17.73, BHV ≥ 20.53, BVDV ≥ 19.00, and BPIV-3 ≥ 16.27. On the other hand, the cumulative log reduction factors achieved were as follows: BPV ≥ 16.95, BHV ≥ 20.22, BVDV ≥ 19.27, and BPIV-3 ≥ 15.58.

CONCLUSIONS

Treatment with 70% ethanol, 4% sodium hydroxide, or gamma irradiation was found to be very effective in virus inactivation, since all viruses were at undetectable levels during each process. We have no doubt that application of this established process to bovine bone graft manufacture will be effective and essential.

Maturation of the Gag core decreases the stability of retroviral lipid membranes

To better understand how detergents disrupt enveloped viruses, we monitored the biophysical stability of murine leukemia virus (MLV) virus-like particles (VLPs) against a panel of commonly used detergents using real-time biosensor measurements. Although exposure to many detergents, such as Triton X-100 and Empigen, results in lysis of VLP membranes, VLPs appeared resistant to complete membrane lysis by a significant number of detergents, including Tween 20, Tween 80, Lubrol, and Saponin. VLPs maintained their structural integrity after exposure to Tween 20 at concentrations up to 500-fold above its CMC. Remarkably, VLPs containing immature cores composed of unprocessed (uncleaved) Gag polyprotein were significantly more resistant to detergent lysis than VLPs with mature cores. Although the maturity of retroviral Gag is known to influence the stability of the protein core structure itself, our studies suggest that the maturity of the Gag core also influences the stability of the lipid bilayer surrounding the core.

Virus reduction in an intravenous immunoglobulin by solvent/detergent treatment, ion-exchange chromatography and terminal low pH incubation

Virus reduction by several steps in the manufacturing process for the intravenous immunoglobulin Vigam(®), has been investigated. The solvent/detergent step based on treatment with 0.3% tri-n-butyl phosphate and 1% polysorbate 80 at 37 °C, was confirmed to be effective for a range of enveloped viruses. Virus infectivity was undetectable i.e. >6 log inactivation within 30 min of the standard 6 h process. This was consistent over the range of conditions tested i.e. solvent/detergent and protein concentration, temperature and pH. The ion-exchange chromatography step in the process was also able to remove some viruses. Virus spiked followed by blank column runs confirmed the effectiveness of the sanitisation step for ensuring there was no virus cross contamination between column runs. The terminal low pH incubation step was also able to inactivate enveloped viruses, as well as some non-enveloped viruses. The combination of these three steps ensures a high margin of virus safety for this product.

Robustness of solvent/detergent treatment of plasma derivatives: a data collection from Plasma Protein Therapeutics Association member companies

BACKGROUND

Solvent/detergent (S/D) treatment is an established virus inactivation technology that has been applied in the manufacture of medicinal products derived from human plasma for more than 20 years. Data on the inactivation of enveloped viruses by S/D treatment collected from seven Plasma Protein Therapeutics Association member companies demonstrate the robustness, reliability, and efficacy of this virus inactivation method.

STUDY DESIGN AND METHODS

The results from 308 studies reflecting production conditions as well as technical variables significantly beyond the product release specification were evaluated for virus inactivation, comprising different combinations of solvent and detergent (tri(n-butyl) phosphate [TNBP]/Tween 80, TNBP/Triton X-100, TNBP/Na-cholate) and different products (Factor [F]VIII, F IX, and intravenous and intramuscular immunoglobulins).

RESULTS

Neither product class, process temperature, protein concentration, nor pH value has a significant impact on virus inactivation. A variable that did appear to be critical was the concentration of solvent and detergent.

CONCLUSION

The data presented here demonstrate the robustness of virus inactivation by S/D treatment for a broad spectrum of enveloped test viruses and process variables. Our data substantiate the fact that no transmission of viruses such as human immunodeficiency virus, hepatitis B virus, hepatitis C virus, or of other enveloped viruses was reported for licensed plasma derivatives since the introduction of S/D treatment.

Inactivation of vesicular stomatitis virus through inhibition of membrane fusion by chemical modification of the viral glycoprotein

Membrane fusion is an essential step in the entry of enveloped viruses into their host cells triggered by conformational changes in viral glycoproteins. We have demonstrated previously that modification of vesicular stomatitis virus (VSV) with diethylpyrocarbonate (DEPC) abolished conformational changes on VSV glycoprotein and the fusion reaction catalyzed by the virus. In the present study, we evaluated whether treatment with DEPC was able to inactivate the virus. Infectivity and viral replication were abolished by viral treatment with 0.5mM DEPC. Mortality profile and inflammatory response in the central nervous system indicated that G protein modification with DEPC eliminates the ability of the virus to cause disease. In addition, DEPC treatment did not alter the conformational integrity of surface proteins of inactivated VSV as demonstrated by transmission electron microscopy and competitive ELISA. Taken together, our results suggest a potential use of histidine (His) modification to the development of a new process of viral inactivation based on fusion inhibition.

Good manufacturing practice production of adenoviral vectors for clinical trials

The increasing importance of recombinant adenoviral vectors for gene therapy, cancer therapy, and the development of prophylactic and therapeutic vaccines has led to worldwide efforts toward scalable process development suitable for commercial manufacturing of replication-deficient adenoviral vectors. This review focuses on the manufacturing of adenovirus for clinical trials in the context of good manufacturing practice conditions and regulations.