Filenews 18 October 2021
Symptoms: fever, cough, chills... The feature: strong mutations. The flu arrives in the northern hemisphere and with it the vaccination campaign. Until now vaccines against this virus have been using technologies known, but not 100% effective, and the emergence of vaccines with messenger RNA can change the facts.
More and more laboratories are starting to develop vaccines against the flu virus using this new technology. Sanofi, the world's leading pharmaceutical company in flu vaccines, has thus begun testing for a vaccine with monovalent RNA - targeting a single strain of the virus - and next year will begin trials for a four-patient vaccine.
The American Pfizer proceeded in September with the first injections to humans of a flu vaccine that uses the messenger RNA, already used in its vaccine against Covid-19. The American biotech company Moderna began testing in early July.
But what is interesting about this technology, which has proven its effectiveness against Covid-19, but has never been used against other viruses?
Flu vaccines have been around for years. However, their effectiveness is not complete: they use inactivated viruses, which must be prepared long beforehand and have an effectiveness ranging from 40% to 60%, even 70%.
"Six months before the epidemic, we are evaluating the strains that are circulating the most. Sometimes we make a mistake and this creates a significant increase in mortality," explains Claude-Anies Reno, an immunologist and research director at Inserm.
Attractive market
After all, "the problem when we inactivate a virus to prepare a vaccine is that this can destroy certain surface proteins," reno clarifies, the same ones that trigger the immune response.
On the contrary, messenger RNA does not require the production of antigens (the substance foreign to the body that causes the immune response) in millions of eggs, since it is the human cell that will produce, itself, the proteins of the virus.
"If the World Health Organization (s.s.: which identifies the strains to be used) warns that the prevailing strains have changed, we will be able to change much faster (the vaccine) with RNA, than with existing technology," underlines Jean-Jacques Lefin, an analyst at Bryan, Garnier & Co. The result is an increased efficacy that can reach 95%.
Consequently, many researchers are involved in the subject. Norbert Pardi, a vaccine specialist at the University of Pennsylvania, was particularly concerned with the issue by creating, thanks to messenger RNA, many antigens in a single vaccine, which he tested on mice.
"These multivalent vaccines will likely cause an overall higher immune response" than today's flu vaccines, he told The French Agency recently.
This technology does, however, have difficulties, including the maintenance of vaccines at a very low temperature.
"We will have to reach thermostable vaccines, which are kept in the refrigerator at 2 to 8 degrees Celsius, in a syringe. There is a lot to be done to be able to turn messenger RNA towards the flu," Explained Toma Triomph, vice president of Sanofi's vaccine industry, recently explained.
And we must not forget "the question of acceptance: will the population be reassured, by the time these vaccines come, the population will be reassured, with regard to this technology, or will they continue to have reservations?" asks Jean-Jacques Lefin.
However, no one is discouraged. "Sanofi understood that she cannot ignore this technology. Flu vaccines represent sales of 2.5 billion euros each year for them," he adds.
"It's a very attractive market for large labs. Apart from Moderna, which is new in this field, the others, such as Sanofi, AstraZeneca or GSK, are very well positioned when it comes to influenza," observes Jamila El Bugrini, a biotechnology expert at brokerage analysis firm Invest Securities.
"This represented $5 billion in sales in 2020. In 2021, $6.5 billion is expected, even $7 billion," he explains, while estimating annual growth for 2020-2026 at 7% to 8%.
ANA-MPA
