LONDON – Valneva SA’s COVID-19 vaccine, VLA-2001, prompted a stronger immune response with fewer side effects than Astrazeneca plc’s product, according to headline data from the phase III trial. Shares in Valneva (NASDAQ:VALN) shot up by nearly 40% to close Oct. 18 at $39.21 when the data were announced, partly repairing the damage on Sept. 13 when the U.K. government cancelled a $1.65 billion contract with the French vaccines specialist for 100 million doses.