Producing vaccines without the use of chemicals

into the suspension containing the pathogens - in fact, for an even dose distribution, liquid levels should not exceed 200 micrometers. Because there were no existing technologies capable of meeting these requirements, Fraunhofer IPA developed two new methods from scratch. In the first method, a cylinder is continuously wetted with the pathogen suspension, irradiated, and the inactivated liquid transferred into a sterile vessel. In other words, there are two reservoirs of liquid: one containing the active and one containing the inactive pathogens - connected to one another via a constantly turning cylindrical vessel or tumbler. “It’s a continuous process that can easily be scaled up for the mass production of vaccines,” says Thoma. The second method is more suited to lab-scale applications, in which small quantities of vaccine are produced for research or drug development purposes. In this instance, the solution containing the pathogens is placed in bags, which are then passed through the electron beam using a patented process.

A collaborative undertaking
This kind of project calls for a range of expertise that is perfectly covered by the four Fraunhofer Institutes involved in the initiative. Researchers at Fraunhofer IZI took responsibility for cultivating the various pathogens – including one for avian flu and one for equine influenza. “Following the irradiation, we also worked with our colleagues at Fraunhofer IGB to determine whether the pathogens had been fully inactivated, thus providing effective vaccine protection,” says Dr. Sebastian Ulbert, head of department at Fraunhofer IZI and the initiator of the project. The expertise in electron beam technology came from researchers at Fraunhofer FEP, who developed a system capable of delivering the low-energy electron beams at precise doses – this is necessary because, while the aim is to reliably inactivate the pathogen, care must also be taken to preserve the pathogen structure so that patients’ immune systems can produce the corresponding antibodies.

The new technology has already been implemented, and not only on the laboratory scale: “In the fall of 2018, a research and pilot facility entered into service here at Fraunhofer IZI. Using our continuous module – the wetted tumbler – we are currently able to produce four liters of vaccine per hour,” says Ulbert. That is not far off industrial scale, given that, for certain vaccines, 15 liters of pathogen suspension can yield a million doses of vaccine.

Discussions are already underway with partners in industry. However, it will be another two to four years before vaccines produced using electron beams can be tested in clinical trials.