Do anti-covid vaccines quickly become obsolete in the face of virus mutations? Some start-ups are working on vaccines that will remain in effect for years or longer. But the possibility is still very uncertain.
“It can protect for many years”, assures AFE Alexis Peroles, the boss of OSE Immunotherapeutics, about a vaccine project for which this French startup has just started its first clinical trial.
Promise is a vaccine that prevents the presence of variants, there are new strains of coronaviruses that differ from those from which vaccines were first developed.
This is one of the great current unknowns of the epidemic: to what extent are the currently administered vaccines, like American Pfizer, effective when these variants multiply?
So far, they seem to be holding up well, but Pfizer’s owner, Albert Borla, recently, considered the possibility that he would have to inject a newly updated dose of his vaccine every year.
Facing this challenge, many biotechs are following a different path from current vaccines: they first seek to stimulate T lymphocytes, part of the immune response that focuses on the detection and elimination of previously infected cells – and viruses. But not only.
Vaccines in circulation, on the other hand, first target the production of antibodies, which directly detect and destroy the virus before it infects a cell. This does not mean that these vaccines do not induce any T cell response – the first data are rather encouraging – but this is not their priority angle of attack.
However, T lymphocytes theoretically have several advantages over antibodies. They can live longer in the body and react to virus components that are less likely to be mutated than detected by antibodies.
In France, the track “T Response” is performed by OSE and Lyon, a contestant from Osivax, who even promises a “universal” vaccine, ready to respond to any possible variant. is. The state has given them millions of euros in funding, while France lags behind in the development of a covid vaccine.
These projects are isolated because some laboratories believe in a universal vaccine. Of the nearly 400 anti-covid vaccine projects identified by the World Health Organization (WHO), only a few claim this perspective.
The most advanced is the American ImmunityBio which was published last month rather than encouraging results yet is still very preliminary.
Because the reality of these vaccines is still very uncertain. No related group makes a single promise before next year and many scientists doubt that this leadership will succeed.
Some people are surprised that it is not confusing to react in advance to the emergence of new strains in the future.
“When there is a mass vaccination, it is in itself (…) a pressure that can lead the virus to develop so as to avoid the vaccine, whatever it is”, AFP said. Warned the British virologist Julian Tang, who therefore sees “double-edged swords” in vaccines designed to make a very wide brew.
The second big question is that if we prepare a response instead of T lymphocytes, to what extent will our body resist the virus.
“I have doubts about the effectiveness of such vaccines,” French virologist Yves Gaudin told AFP.
Lymphocytes and antibodies work in the tandem. If antibodies do not respond well, T lymphocytes “will not be of much use”, he stressed, adding that the norm is a vaccine that is effective on both schemes.
But, well, if these new vaccines become a reality, they will be injected, at least in Europe and the United States, to people who have already received current vaccines. Therefore their antibodies will be prepared.
It is argued by Mr. Peyroles in OSE Immunotherapeutics to ensure that his vaccine would, in the event of a positive result, gain its place.
With this vaccine, “you develop by fullness and comprehensiveness, over breadth and duration, thanks to defense early vaccines,” he says.
He also argues that such a vaccine would provide protection to individuals who naturally struggle to develop antibodies, for example because they have certain cancers and diabetes.