Valneva says no conclusions should be drawn on its vaccine from UK booster study

Reuters

Published Dec 03, 2021 15:27

Updated Dec 03, 2021 16:56

PARIS (Reuters) -French biotech firm Valneva said on Friday no conclusions should be drawn on the effectiveness of its COVID-19 vaccine by a British study, which found it was the only shot out of seven that offered no immunity boost when given to people previously immunized with Pfizer (NYSE:PFE)'s vaccine.

Shares in Valneva fell by up to 24% on Friday following the publication of results of Britain's COV-Boost study, which looked at the effectiveness of alternative vaccines as boosters for people who previously received Pfizer or AstraZeneca (NASDAQ:AZN) shots.

All seven vaccines given in the COV-Boost study increased immunity when given as booster shots to people who had previously received two doses of AstraZeneca's vaccine.

The other six - but not Valneva's VLA2001 - were also found to increase immunity when given to people who had been vaccinated with Pfizer.

Valneva said participants in the study had been given their booster doses after a shorter interval than usual, and that vaccines made from inactivated viruses, such as its candidate, typically require a longer interval to be effective.

"The setting in this study leads us to believe that COV-Boost does not allow any conclusions to be reached regarding the use of VLA2001 as a booster in a real-life setting," it said in an e-mailed statement in response to a Reuters query.

"Valneva believes it is likely that the short interval between the second shot and booster shot could have adversely impacted the results for VLA2001, given that a longer interval is generally required for inactivated vaccines."

The European Union's drug regulator said on Thursday it had started a rolling review of Valneva's vaccine - which could speed up approval of the shot - weeks after the EU signed a supply deal with the company.

Unlike shots by Pfizer-BioNTech, AstraZeneca, Johnson & Johnson (NYSE:JNJ) and Novavax, the Valneva shot exposes the immune system to the entire coronavirus, not just the spike protein.