Enhancement of Cell-Based Vaccine Manufacturing through Process Intensification.

There are many drivers to intensify the manufacturing of vaccines. The emergence of SARS-CoV-2 has only added to them. Since the pandemic began, we have been seeing an acceleration of vaccine development and approval, including application of novel prophylactic vaccine modalities. We have also seen an increase in the appreciation and general understanding of what had been a somewhat obscure discipline. Concurrently, there has been great interest in the application of new understandings and technology to the intensification of biopharmaceutical processes in general. The marriage of these developments defines the field of vaccine manufacturing process intensification Difficulties in its implementation include the many disparate vaccine types-from conjugate to hybrid to nucleic acid based. Then, there are the respective and developing manufacturing methods, modes, and platforms-from fermentation of transformed bacteria to the bioreactor culture of recombinant animal cells to production of virus-like particles in transgenic plants. Advances are occurring throughout the biomanufacturing arena, from process development (PD) techniques to manufacturing platforms, materials, equipment, and facilities. Bioprocess intensification refers to systems for producing more product per cell, time, volume, footprint, or cost. The need for vaccine manufacturing process intensification is being driven by desires for cost control, process efficiency, and the heightened pressures of pandemic response. We are seeing great interest in the power of such disciplines as synthetic biology, process simplification, continuous bioprocessing, and digital techniques in the optimization of vaccine PD and manufacturing. Other powerful disciplines here include process automation, improved monitoring, optimized culture materials, and facility design. The intent of this short commentary is to provide a brief review and a few examples of the exciting advances in the equipment, technology, and processes supporting this activity.

Exosome manufacturing status.

Exosomes are secreted by mammalian cells and are widely distributed in cellular systems. They are a medium of information and material transmission. The complexity of exosome nature and function is not thoroughly understood. Nevertheless, they are being confirmed as mediators of intercellular communication and play significant roles in many physiological and pathological processes. Significant obstacles to the efficient and robust isolation of large quantities of pure and specific exosomes still exist. These include a lack of understanding of the relationship between exosome characteristics and function, and a shortage of scalable solutions to separate specific exosomes from other large entities remain. Hence, generic production platforms are desired. While solutions suitable for exosome manufacturing under GMP are available, most have been developed for other purposes.

Digital biomanufacturing supporting vascularization in 3D bioprinting.

Synergies in bioprinting are appearing from individual researchers focusing on divergent aspects of the technology. Many are now evolving from simple mono-dimensional operations to model-controlled multi-material, interpenetrating networks using multi-modal deposition techniques. Bioinks are being designed to address numerous critical process parameters. Both the cellular constructs and architectural design for the necessary vascular component in digitally biomanufactured tissue constructs are being addressed. Advances are occurring from the topology of the circuits to the source of the of the biological microvessel components. Instruments monitoring and control of these activates are becoming interconnected. More and higher quality data are being collected and analysis is becoming richer. Information management and model generation is now describing a "process network." This is promising; more efficient use of both locally and imported raw data supporting accelerated strategic as well as tactical decision making. This allows real time optimization of the immediate bioprinting bioprocess based on such high value criteria as instantaneous progress assessment and comparison to previous activities. Finally, operations up- and down-stream of the deposition are being included in a supervisory enterprise control.

Optimization of HIV-1 infectivity assays.

HIV-1 reporter cell lines are the backbone of diagnostic assays, vaccine and drug development efforts. Performing HIV-1 infection experiments in a T cell background is desirable for many reasons. However, a low susceptibility to infection with primary patient isolates in available reporter T cell lines has limited such efforts. We here demonstrate that optimization of HIV-1 receptor expression and the utilization of serum free medium compositions can increase susceptibility of reporter T cell lines to HIV-1 infection by up to two orders of magnitude.