Is the Spike protein a toxin? 

An article is circulating on Telegram echoing statements by immunologist Byram Bridle, who in an interview on a Canadian radio programme claimed that the Spike or S protein generated after the injection “is a toxin”. It is DECEITFUL. The S protein is not a toxin, nor is it a risk for health once the vaccine has been inoculated, although it is harmful when a natural covid-19 infection takes place.

"SARS-CoV-2 has a specific protein on its surface. We now know that the S protein enters into circulation. We think that the S protein could be a great antigenic target; we never imagined it was a toxin. So by vaccinating people, we are inadvertently inoculating them with a toxin."

A toxin is, according to the British Encyclopedia, “any substance poisonous to the organism”, that is, it is a rather broad concept. Sometimes, he continues, "it is a term restricted to poisonous elements spontaneously produced by living organisms (biotoxins)" and that "in addition to poisons produced by microorganisms such as bacteria, dinoflagellates and algae, there are toxins from fungi (mycotoxins), higher plants (phytotoxins) and animals (zootoxins)". 

Based on this definition, the S protein that is located on the surface of SARS-CoV-2 is, as it is known that when we develop covid-19 disease, it is "the one that allows the virus to bind to the receptor on the surface of human cells (ACE2) and infect them," recalls Adelaida Sarukhan, immunologist and scientific writer at the Institute for Global Health (ISGlobal, in Catalan) in Barcelona. In these cases, the protein can get out of control and be able to circulate in the bloodstream, reach other organs and attack them. 

“In the context of a natural infection, it has been proposed that soluble pieces of the Spike protein released by the infected cells can play a role in amplifying the pathogenesis of the disease due to the adhesion to the ACE receptors in the lungs”, the expert explains. 

This is different if we have obtained the protein through vaccination: "The Spike protein produced as a result of vaccination with mRNA-based injections or viral vectors is not soluble, but it remains stuck to the cell membrane," says Sarukhan. "Moreover, its production is highly localised in the area of injection (the arm) and, as the EMA itself explains, experiments in mice show that practically no circulating free protein is detected. So no, the vaccines are designed so that the S protein that is produced after injection into the cells of our body remains attached to the cell membrane, so that it cannot escape, and thus not be a harmful element or be considered a toxin. 

Choosing protein S to develop the vaccine was not by chance

Although the 'eureka!' moment may exist in science on occasion, the selection of the S protein among many others in the coronavirus was not accidental. Before SARS-CoV-2 came along, there were SARS (2002) and MERS (2012), two respiratory diseases also caused by a type of coronavirus that allowed us to know how to anticipate and develop better treatment strategies against covid-19: "The experience gained with other coronaviruses (SARS, MERS) had already indicated that the safest bet for generating good immunity against a coronavirus was to use the Spike protein. Thanks to this, we were able to make such rapid progress with the SARS-CoV-2 vaccines," the immunologist summarises.

This does not exclude that in the future we may see vaccines that include "other viral proteins, such as N (nucleocapsid), to enhance or diversify the immune response," he concludes. 

Numerous hoaxes circulating about the spicule protein and its effects on the body after vaccination, such as that it can be transmitted through the air, or that it is the origin of the rare thrombosis cases. Both of these claims are false.