A new vaccine for Europe

A new vaccine (“Nuvaxovid”) from the US biotechnology company Novavax has been approved by the European Medicines Agency (EMA).

By Jean-Marc Sabatier *

The European Medicines Agency has just authorized Novavax’s vaccine, which uses more conventional technology than that of mRNA vaccines.
It is a so-called “recombinant” or “subunit” vaccine, with a recombinant protein (modified S protein), and is therefore different from current vaccines with mRNA, viral vectors or inactivated viruses.

Composition : Five micrograms of antigen (pre-fusion form of modified S protein including the transmembrane domain) and fifty micrograms of adjuvant, including Matrix-M (a derivative of Panama wood saponin).

Advantage : Quantity of fixed antigen injected (the potential deleterious effects must be transient because the peak protein will be degraded without possible renewal).

Major drawbacks:

• The vaccine is based on the (modified) viral spike protein, which is itself deleterious if it is able to bind to its ACE2 receptor in the renin-angiotensin system (as well as to the TLR4 receptor in innate immune cells). This is all the more likely as it appears that the modified spike protein has the capacity to combine to form trimers (like those present on the surface of the virus, called spicules).
• The peak protein must be that of the historic “Wuhan” strain which disappeared about 18 months ago; thus, the real efficacy of this vaccine could be much lower than that described, in particular with the emergence and the preponderance of the delta and omicron variants of SARS-CoV-2.

ACE2 : angiotensin-2 converting enzyme
TLR4 : Toll-like receptor-4

* Jean-Marc Sabatier, research director at the CNRS and doctor in cell biology and microbiology, affiliated to the Institute of Neurophysiopathology (INP), of the University of Aix-Marseille. Editor-in-chief of international scientific journals: “Coronaviruses” and “Infectious Disorders – Drug Targets”.