How is Matrix-M made?

Soapbark trees are grown and harvested in very regulated, controlled conditions. When the trees are pruned, bark is harvested and ground into fine, pure powder. Saponins are extracted and prepared for use. Once all the processing steps are complete, the Matrix-M adjuvant is mixed with vaccine nanoparticles to produce the finished, ready-to-use vaccine. Saponins, from the Quillaja saponaria tree, help generate a robust immune response.1

Matrix-M adjuvant production process
Trees are pruned and bark is harvested

Saponins are found in the tree’s bark. Bark is harvested sustainably, without felling the whole tree.

Quilliaja saponaria (Soapbark) tree. Bark containing saponins.
Bark is processed

Bark extract is processed to isolate saponin subtypes components that are then freeze-dried into powders that contain highly purified saponin molecules.

Fraction-A. Fraction-C.
Matrix-M adjuvant formation

The two saponin subtypes are formulated in a liquid format, producing the distinctive structures of Matrix-A and Matrix-C and mixed using a precise ratio to form Matrix-M adjuvant.

Matrix-A adjuvant. Matrix-C adjuvant.
Final vaccine

Matrix-M adjuvant is mixed with the vaccine antigen to form the final vaccine product.

Vaccine antigen, Matrix-A and Matrix-C

Infographic displaying the Matrix-M adjuvant production process

The harvesting practice of Quillaja is regulated within Chile, regardless of use.  

The pharmaceutical industry uses a relatively small proportion of the total amount of saponins produced, which are also used in foods and other products. Saponins used in vaccines must be of extremely high quality and part of a sustainable supply. 

Due to the high demand for this naturally occurring product, the harvesting of saponin-producing trees is highly regulated. In Chile, landowners need a special permit to cut down a Quillaja saponaria Molina tree and are only allowed to prune up to 35% of its biomass every 5 years.2 Significant investments have been made in forestry and production practices to ensure a sustainable supply. Specialized low-impact harvesting methods have been developed,2 and harvesting is coupled with reforestation efforts. Saponin extraction methods are also under constant review to improve efficiency and quality, and Novavax is committed to the responsible, sustainable harvesting of saponins for use in our vaccines.

  1. Keech C, et al. N Engl J Med. 2020;383(24):2320–2332.
  2. San Martín R, Briones R. Econ Bot. 1999;53:302–311.