Bavarian Nordic A/S announced the results of a six-month follow-up analysis from a Phase 2 clinical trial of ABNCoV2, a VLP-based, non-adjuvanted COVID-19 booster vaccine candidate. Previously reported results from the trial showed, that vaccination with 100ug ABNCoV2 in 103 seropositive subjects was able to demonstrate a strong boosting effect, increasing the existing levels of SARS-CoV-2 neutralizing antibodies against both the Wuhan variant and variants of concern (Alpha, Beta, Delta and Omicron) to levels reported to be highly efficacious (>90%) against SARS-CoV-21. A cohort of 41 subjects were followed for six months post vaccination.

From this cohort, two subjects with confirmed COVID-19 disease were excluded from the immune analysis. Six months post vaccination, neutralization titers were six times higher than pre-boost titers against Wuhan and nearly 10 times higher than the pre-boost titers for Omicron BA.1. This represented less than a 50% decline in the peak neutralizing titers after six months and compared to the data published for mRNA vaccines2,3,4, the antibody decay appears less sharp, indicating a potentially longer duration of protection across variants of concern.