Valneva SE announced positive homologous booster data from the Phase 1/2 study, of its inactivated, adjuvanted COVID-19 Vaccine candidate, VLA2001. Initial results confirm that VLA2001 significantly boosted immunity in participants who received VLA2001 as a primary vaccination.

In the study, 77 of the 153 original Phase 1/2 study participants, aged 18-55 years, received a booster dose seven to eight months after completion of their primary immunization with either a low, medium or high dose of VLA2001. All participants received a single booster vaccination with VLA2001 at the same (high) dose level used in the pivotal Phase 3 “Cov-Compare” trial. IgG Antibody titers (spike Protein -based) were measured at the time of the booster as well as two weeks after the booster dose with 45 of the 77 boosted participants included in the final analysis.
A third dose of VLA2001 elicited an excellent anamnestic response, with similar antibody levels observed whether participants were initially vaccinated with a low, medium or high dose (95%). This represents a strong boosting effect, increasing levels of antibodies against the Wuhan virus 42- to 106-fold, depending on the pre-boosting levels of antibodies.
Antibody levels measured two weeks after the booster dose were approximately four-fold higher compared to those observed two weeks after primary immunization.
Valneva will also evaluate the sera from the boosted participants for cross-neutralization against Variants of Concern, including Omicron.