 U.S.-listed shares of Valneva SE VALN, 12.95 were up 14.9 in trading on Thursday after the company said in a news release that its experimental COVID-19 booster shot boosted antibody levels in people who were already vaccinated with Valnevas primary series of shots. The Phase 12 study assessed antibody levels between seven to eight months after participants had been fully vaccinated with the companys shots, which are still considered investigational. 