At 1/100 dilution, all samples had potent neutralizing activities capable of neutralizing at least 60% of input virion, with median level activities larger than 95% (Fig. 2C).
In contrast, H1N1 vaccination alone in influenza-naive mice elicited only vigorous homologous neutralizing activities but not cross-reactive neutralization activities.
Of serum samples that had MERS-CoV neutralizing antibody titers >1,280, a total of 24.2% (94/389) had concomitant neutralizing activities against BCoV.
While without prior sCD4 treatment, JR-FL was difficult to neutralize by sera from all three trials (Fig. 3B), significant neutralizing activities against JR-FL Env pseudotyped viruses upon exposure to sCD4 were found in these sera: 7 out of 12 (58%) from HVTN 203, 10 out of 12 (83%) from HVTN 041, and 20 out of 21 (95%) from DP6-001 with positive neutralizing activities (Fig 3C).
Neutralizing activities against SS1196, a primary isolate that is moderately sensitive to neutralization, allowed for some differentiation of the neutralization potential of each trial sera (Fig 1B).
Sera of the four recipients showed neutralizing activities against HPV16 and 52.
The B1 also has potent neutralizing activities against infection by pseudovirus expressing SARS-CoV S protein in vitro.
There was no significant difference in neutralizing activities between lipo1-J3 and lipo2-J3 compared to free J3-His (Fig. 6b), revealing no contribution from the size differences.
Both 1A5 and 2C5 possessed potent neutralizing activities, although they directed against distinct conformation-dependant epitopes as shown by ELISA and binding competition assay.
A single intraperitoneal injection of these antibodies conveyed distinct levels of adult and in utero protection from ZIKV infection, which closely mirrored their respective in vitro neutralizing activities.
Although neutralizing antibodies are believed to be protective, most of the antibody species that have neutralizing activities also have infection-enhancing activities at subneutralizing doses.
