Binding and neutralization titer decline over time.

Binding titers to wild-type S protein (BAU/ml) of 1:100,000 diluted sera (A) and neutralization half-maximal inhibitory concentration (IC50) titers (IU/ml) of D614G pseudovirus (B) collected post complete vaccination and pre-booster for the four vaccination groups. The lower cutoff for binding was set at 30 BAU/ml (grey shading) and for neutralization titers at 2 IU/ml. Lines connect the geometric mean titers (GMT) of four weeks post complete vaccination and GMT of pre-booster titers per group. Vaccine groups are indicated by colors with BNT162b2 in green, mRNA-1273 in purple, AZD1222 in orange and Ad26.COV2.S in blue. (EMF)