They took a while, but they ended up coming.
The preliminary results of the vaccine candidate of French Sanofi, coupled with the British GSK, were announced on Monday, several months after its competitors.
And according to the manufacturer, the product works: "We have between 95 and 100% seroconversion, therefore the appearance of antibodies when you are vaccinated", welcomed its president Olivier Bogillot.
Data obtained on 18-95 year olds that will have to be confirmed before seeing this new anti-Covid weapon on the market.
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When to expect to have it?
Its commercialization is expected by the end of this year, but it is still necessary that everything goes well by then! The results proclaimed on Monday are said to be phase 2. "This is the step that allows to validate the safety of the product, to measure the immune response and to choose the right dosage", summarizes Dominique Deplanque, pharmacologist and clinical research expert at the Lille University Hospital (North). But only the essential phase 3 "will make it possible to know if - and how - the vaccine reduces the probability of being sick".
Scheduled to start in the coming weeks, it will include 35,000 volunteers. "It will not be so simple, especially to have a diversity of age, warns the vice-president of the French Society of Virology, Mylène Ogliastro. In Europe or the United States, a large part of the elderly have already received their injection. However, the results must be robust. It should be noted that, like the four vaccines already in circulation, its marketing authorization could be granted before the end of the phase 3 trial.
What is its technology?
Exit the messenger RNA of Pfizer and Moderna. Exit the AstraZeneca and Janssen adenoviruses. Hello, the "recombinant protein with adjuvant"! “It's a great innovation from the 1980s,” notes Professor Ogliastro. Here, we will administer to the patient the typical Spike protein of the coronavirus, after having made it in the laboratory by means of another virus, the insect baculovirus.
“Before its injection, the protein is purified and an adjuvant is added to enhance the immune response. The product is delivered
completely
to the body so that it can be on alert and defend itself in the event of a real infection, ”explains Dominique Deplanque. A technology already used in Sanofi's papillomavirus (HPV) vaccine. And also by Novavax, an American company which is developing another candidate vaccine against Covid, and is also testing a unique influenza-Covid serum.
Is it effective against variants?
Difficult today to say, because it was designed on the "historic" strain of the virus. Phase 3 will in particular make it possible to test its administration in two doses against the South African variant. “A priori, there is no reason to think that it would not be effective, reassures Mylène Ogliastro. But if this were to be the case, its drawback is that it is less adaptable than messenger RNA vaccines which, on the other hand, can be quickly modified. "
Doesn't he come after the battle?
The usefulness of this product, expected at least this fall, almost a year after its competitors, questions while 20 million French people have already received a first dose. "It's a very good booster vaccine," Sanofi president Olivier Bogillot defended on Monday. This recall, single or regular, is in fact not excluded. “And then, it is not only the Western countries that must be vaccinated, but the whole planet! The more we have available, the better, ”notes Professor Deplanque. Two strong points: it should be inexpensive and easily stored.