Bavarian Nordic Provides Update on COVID-19 Booster Vaccine Program

• ABNCoV2 and the comparator vaccine demonstrated a reduced level of neutralizing antibodies against a circulating variant (Omicron XBB.1.5) in Phase 3 study.
• cVLP platform has proven its ability to induce strong and lasting immunity against the target virus, but Bavarian Nordic sees no commercial opportunity for the vaccine, as the platform is not suitable for quick adaptions to emerging variants.
• The Company will continue its dialogue with authorities on how best to leverage the learnings about the platform in a potential future pandemic situation.

COPENHAGEN, Denmark, August 31, 2023 – Bavarian Nordic A/S (OMX: BAVA) today reported additional Phase 3 results and provided an update on the development program for its cVLP-based COVID-19 booster vaccine candidate, ABNCoV2.

As previously reported, two weeks post a booster vaccination with ABNCoV2, the levels of neutralizing antibodies against the original SARS-CoV-2 variant (Wuhan index virus) were non-inferior to those stimulated in people vaccinated with Comirnaty and this result met the primary objective of the Phase 3 study. The Wuhan variant is no longer the primary concern, as the virus has mutated creating new circulating variants, such as Omicron XBB.1.5. In a follow-up analysis, when looking at this more distant variant, the levels of neutralizing antibodies induced by ABNCoV2 were lower than those stimulated by the non-adapted Wuhan-based Comirnaty, and fewer people had detectable antibodies following ABNCoV2 (64%) versus Comirnaty (85%). The levels of neutralizing antibodies induced by both vaccines were much lower than against the Wuhan variant.

A 6-month follow-up analysis will be conducted to evaluate the durability of the antibody responses from booster vaccination with ABNCoV2 and Comirnaty, which, if the Phase 2 durability results for ABNCoV2 are confirmed, may confirm an advantage over the comparator vaccine.

While safety data from the Phase 3 study will continue to be collected for 6 months, safety data from 4,205 individuals followed up for 2 months post vaccination showed ABNCoV2 to be well-tolerated with no serious adverse events being reported.

These data support the current position of many of the regulators (e.g. FDA, EMA and WHO) that request variant-specific COVID vaccines that will likely have to be adapted each year like flu vaccines. Unfortunately, ABNCoV2 cannot be readily adapted within the seasonal timeframe and as such ABNCoV2 no longer represents a commercial opportunity for Bavarian Nordic.