The A’s have it but the B’s don’t in Moderna Inc.’s pivotal phase III study of mRNA-1010, a seasonal flu vaccine for adults living in the southern hemisphere. Interim results showed the vaccine achieved superiority on seroconversion rates for influenzas A/H3N2 and A/H1N1, superiority on geometric mean titer ratios for influenza A/H3N2 and noninferiority on geometric mean titer ratios for influenza A/H1N1. However, noninferiority was not met for the endpoints against the influenza B/Victoria- and B/Yamagata-lineage strains.