Moderna said vaccination with its COVID-19 vaccine produced neutralizing titers against all variants tested.
This included additional versions of the Beta variant (B.1.351, first identified in South Africa), three lineage variants of B.1.617 (first identified in India), including the Kappa (B.1.617.1) and the Delta variants (B.1.617.2); the Eta variant (B.1.525, first identified in Nigeria); and the A.23.1 and A.VOI.V2 variants first identified in Uganda and Angola, respectively.
The study methodology involved using serum samples from eight participants obtained one week after participants’ second dose of the primary series in the Phase 1 clinical trial of Moderna's COVID-19 vaccine. These most recent data, which were submitted as a preprint to bioRxiv, include neutralization assays against additional variant strains.
The current analysis showed minimal impact on neutralizing titers against the Alpha and A.23.1 variants relative to those against the ancestral strain (D614G). This analysis also showed a modest reduction in neutralizing titers against the Delta (2.1-fold), Gamma (P.1, 3.2-fold), Kappa (3.3-3.4-fold), and Eta (4.2-fold) variants relative to those against the ancestral strain.
Consistent with previous results, a 7.3 or 8.4-fold reduction in neutralizing titers was observed with the additional versions of the Beta variant relative to the ancestral strain. Additionally, an 8.0-fold reduction in neutralizing titers relative to the ancestral strain was observed with A.VOI.V2, the variant first identified in Angola, but currently not designated as a variant of concern or interest.
