Table 4.

Model parameters estimated on Phase I participants by Pasin et al.¹⁶ and the new estimates obtained on pooled Phase I and Phase II data and considering adjustment for laboratory effects.

Parameter	Meaning	Phase I data		Phase I & II data
		Mean	95% CI	Mean	95% CI
Fixed effects
δAb	Antibody decay rate (day−1)	0.029	[0.027; 0.033]
Women				0.0251	[0.0223; 0.0283]
Men				0.0353	[0.0296; 0.0421]
$\log \left(2\right)/{\delta }_{\mathrm{Ab}}$	Antibody half-life (days)	24	[22; 26]
Women				27.6	[24.5; 31.1]
Men				19.6	[16.4; 23.4]
δS	SL ASCs decay rate (day−1)	0.231	[0.15; 0.36]	0.333	[0.326; 0.340]
$\log \left(2\right)/{\delta }_{\mathrm{S}}$	SL ASCs half-life (days)	3.0	[1.9; 4.7]	2.08	[2.04; 2.13]
δL	LL ASCs decay rate (year−1)	3.16 × 10−4	[1.46; 7.03] × 10−4	1.25 × 10−4
$\log \left(\mathbf{2}\right)/{\mathit{\delta }}_{\mathit{L}}$	LL ASCs half-life (years)	6.0	[2.7; 13]	15.0
ϕS	SL ASCs influx (EU/mL/day)	2755	[1852; 4100]
Mean Age (31.3 years)				3057	[2418; 3865]
FC ΔAge = + 1 yeara				0.934	[0.915; 0.954]
ϕL	LL ASCs influx (EU/mL/day)
African part.		16.6	[13.7; 20.1]	10.2	[9.01; 11.4]
Eur. part.		70.7	[54.0; 92.7]	36.6	[27.3; 49.2]
α	Scaling factor—lab effects
αfocus				1.04	[0.93; 1.16]
αQ2sol				1.00	[0.98; 1.02]
Random effects
${\omega }_{{\varphi }_{\mathrm{S}}}$	Sd of RE on ϕS	0.92	[0.83; 1.01]	0.84	[0.56; 1.13]
${\omega }_{{\varphi }_{\mathrm{L}}}$	Sd of RE on ϕL	0.85	[0.78; 0.92]	0.88	[0.81; 0.96]
${\omega }_{{\delta }_{\mathrm{Ab}}}$	Sd of RE on δAb	0.30	[0.24; 0.36]	0.35	[0.29; 0.41]
Error model
σAb	Sd of error model	0.10	[0.10; 0.10]	0.107	[0.101; 0.112]

CI confidence interval, EU ELISA units, Eur. European, FC fold change, LL ASCs long-lived antibody-secreting cells, Part. participants, RE random effects, SL ASCs short-lived antibody-secreting cells, Sd standard deviation.

^aRepresents the multiplicative factor to apply to the value of ϕ_S, obtained for the mean age, for an increase in participant age of 1 year: ϕ_S(Mean Age + 1 year) = ϕ_S(Mean Age) × FC(ΔAge = +1). Therefore, the percentage of decrease of ϕ_S for a participant X years older than the mean age is given by 100×(1−FC(ΔAge = +1)^X).