TABLE 2.

Correlation coefficients between viral neutralization and immunogenicity levels in subgroups based on vaccine 1-to-blood collection interval, and between-cohort comparisons

Immunogenicity measurea	Correlation coefficient (95% CI) short V1b-to-BCc interval	Correlation coefficient (95% CI) long V1-to-BC interval	Fisher’s Z	P value
Anti-spike total	0.61 (0.42 to 0.75)	0.91 (0.85 to 0.95)	−4.37	<0.0001
Anti-spike IgG	0.49 (0.26 to 0.66)	0.89 (0.82 to 0.93)	−4.73	<0.0001
Anti-RBD IgG	0.53 (0.31 to 0.70)	0.91 (0.85 to 0.95)	−5.00	<0.0001
Anti-NTD IgG	0.51 (0.29 to 0.68)	0.88 (0.80 to 0.93)	−4.34	<0.0001
ACE-2 RBD	0.49 (0.27 to 0.67)	0.89 (0.81 to 0.93)	−4.73	<0.0001

^aAll measured as concentrations.

^bV1, first vaccine date.

^cBC, blood collection date.