(Bloomberg) -- Valneva SE said it’s expanding clinical trials of its Covid-19 inoculation and is still in talks with the European Union on a supply contract, as the French company tries to advance its vaccine development after the U.K. government canceled an order this month.

The company said Thursday it has begun enrolling adolescents in a third-phase trial, and it expects ongoing tests to provide some results in the fourth quarter, which are intended to form the basis for gaining regulatory approval for use in adults.

Valneva also said it’s pursuing other customers as well as continuing discussions with the European Commission. The stock plummeted 42% on Sept. 13 after the U.K. canceled its supply contract, alleging that Valneva breached obligations under the agreement. Neither Valneva nor the U.K. has specified the problem.

The French company also said it has begun giving booster shots to adults in an earlier-stage trial.

Valneva’s vaccine works by taking a sample of the disease that has been killed and using it to stimulate an immune response without creating infection.

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