(BFM Stock Exchange) – The specialist in infectious diseases has published results showing that this vaccine has a good persistence of antibodies four years after vaccination.

Valneva still resumes a little altitude on the stock market, this Tuesday, September 30. The action of the specialist in vaccines resumes 9% in the middle of the afternoon, increasing its rise over the whole of 2025 to 131.2%.

The increase of the day is carried by positive data for IXCHIQ, the company’s vaccine against chikungunya. This vaccine is marketed in several countries including Canada, Brazil, the United Kingdom and the European Union.

These data relate more precisely to the persistence of the presence of serum antibodies against chikungunya.

The company conducted by the company has shown that four years after the injection of a dose of the vaccine, the rate of seropositivity (in the medical field the seropositivity reflects the positive reaction to a serum and therefore the presence of antibodies) reached 95% in the 254 adults to have participated in the study.

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Reassuring figures

“These results are online with Valneva’s expectations for this vaccine and confirms a robust and durable persistence of antibodies in all vaccinated age groups,” the company said in a press release.

“There are two aspects: first these data is very good, reassuring, and show that the long -term walking vaccine. Then there is a catch -up effect for the action that was sealed by the announcement of the FDA (Food and Drug Administration, the American health authority, editor’s note)”, comments an analyst.

A month ago, the FDA decided to suspend the license from Ixchiq in the United States, interrupting the expeditions and sales of the vaccine. What had resulted in a plunge of more than 22% of the action. This announcement had also struck the beautiful resumption of the title, which was previously carried by the approval of Ixchiq in Brazil and the expansion of its use to adolescents in Canada.

An intriguing decision of the FDA

The suspension of Ixchiq by the FDA was enough to surprise. In hollow, the French company had made it clear that it did not judge the decision of the American authority justified.

“Valneva believes that these cases have symptoms comparable to those reported above, during clinical trials and after placing the vaccine, especially in the elderly for which the indication of the vaccine includes warnings and precautions,” said company in a statement.

The group continues to “analyze these cases in detail and, if necessary, carry out any procedures relating to the decision of the FDA, in accordance with the applicable legal procedures”, she warned.

The IXCHIQ vaccine had generated a total of 7.5 million euros in sales in the first half of 2025, thus representing less than 10% of the total of Valneva income (91 million euros).

“In the medium term (4-5 years), and according to our estimates, Ixchiq could generate a peak of annual sales around 200 million euros,” said Mohamed Kaabouni, analyst at Portzamparc in April.

Beyond this vaccine, Valneva had announced positive data at the beginning of the month for a phase II test (an intermediate stage) for its Lyme disease vaccine co-developed with the American pharmaceutical giant Pfizer. The title then returned to 10%.