Instead of fighting nature to make vaccines, GSK scientists take advantage of a natural process in bacteria. Gram-negative bacteria naturally shed some of their outer membrane. Using Generalized Modules for Membrane Antigens (GMMA) technology, GSK researchers turn those so-called blebs into treatments.
The GMMA process causes the bacteria to make many of these blebs, which can be engineered to include several antigens, and modified to reduce the natural toxicity of the blebs. That creates a multi-valent vaccine.
“In the end, you have one element that presents several antigens to the immune system” says Giulia Giordano, PhD, vaccine development leader at GSK Vaccines in Belgium. “Having several antigens is sometimes the only way to make a vaccine efficacious for bacterial infections.”
By keeping most of the natural composition of the outer membrane, GMMA technology stimulates the immune system to target the invading bacteria.
This largely natural process also simplifies bioprocessing. After fermentation, just two filtration steps are needed to produce a final product. “This makes the technology quite simple,” continues Giordano. It could also be turned into a continuous process, which would allow a smaller fermenter and production facility in general. As a result, “this can be a very interesting manufacturing process for low-income countries,” Giordano explains. “A vaccine could then be made in the country where it’s needed.”
Especially for low-income countries, GSK is developing vaccines against Salmonella and Shigella using GMMA technology. In addition to being effective, these vaccines need to be easy to distribute. Giordano points out the GSK’s GMMA vaccines are stable across a range of temperatures.
“GMMA technology is a powerful tool to have in-house and apply as needed,” Giordano says. “Of course, using GMMA depends on the bacteria and what the vaccine must perform, but there is a good match for several projects.”