Phase III study results for VLA 2001 show positive immunogenicity and booster data in COVID-19

The Company previously reported immunogenicity data at Day 43 post primary vaccination and has now evaluated immunogenicity in VLA2001-301 trial participants approximately two months following primary immunization (“Day 71”), as part of the prespecified analysis of secondary endpoints. At Day 71, neutralizing antibody titers induced by VLA 2001 were non-inferior to ChAdOx1-S: VLA2001 GMT was 444.0 (95% CI: 414.0, 476.2), ChAdOx1-S GMT was 411.8 (95% CI: 389.7, 435.0). Seroconversion rates remained constant at Day 71 (above 92% in both treatment groups). Additionally, T-cell responses analyzed in a sub-set of the 3,560 trial participants followed for approximately six months after primary vaccination (“Day 208”) showed that VLA 2001 induced broad antigen-specific IFN-gamma producing T-cells reactive against the S-protein, as well as the N- and M-proteins up to Day 208. The safety profile of VLA 2001 continues to be favorable and the vaccine was well tolerated up to Day 208.

The occurrence of COVID-19 cases (exploratory endpoint) was similar between the VLA 2001 and ChAdOx1-S groups, supporting earlier findings. There were no severe COVID-19 cases up to Day 208 in the direct comparative groups (above 30 years of age), which may suggest that both vaccines provided similar protection against severe COVID-19 disease caused by the circulating variant(s) (predominantly Delta). There was one severe COVID-19 case in the 18-29 years of age cohort (n=1040 participants) in a participant with a BMI >40 and history of asthma. A total of 958 participants from the VLA2001-301 trial received a single dose of VLA 2001 approximately eight months after priming with either VLA2001 or ChAdOx1-S (AstraZeneca) to evaluate the booster effect in both homologous and heterologous (“mix and match”) settings. Previously, VLA 2001 showed an excellent immune response after a third dose administered seven to eight months in participants who received VLA 2001 as a primary vaccination in a Phase I/II study.

In both the homologous and heterologous setting, VLA 2001 was able to boost immunity to higher neutralizing antibody titers than following priming, and to levels reported to be highly efficacious (90%) against SARS-CoV-24. Neutralizing antibody titers following a VLA 2001 booster dose administered approximately eight months after primary vaccination were between 3-fold (heterologous) to 28-fold (homologous) higher compared to pre-boost levels, in line with previous VLA 2001 Phase I/II homologous booster results. A booster dose of VLA 2001 was well tolerated by both VLA 2001- and ChAdOx1-S-primed participants. The tolerability profile of a booster dose with VLA 2001 was similar to the favorable profile observed after the first and second vaccination with VLA 2001 in the Phase I/II and initial Phase III trial results.