Table 1.

Deaths averted by switching to hypothetical fractional dosing regimens

NAb ratio (efficacy)	Dose
	1	1/2	1/3	1/4
Switching from 95% effective full dose
1.0 (95%)	0	22 to 47	32 to 69	37 to 80
0.8 (94%)	−2 to −1	21 to 45	31 to 67	37 to 79
0.4 (87%)	−12 to −4	18 to 34	28 to 59	34 to 73
0.2 (76%)	−29 to −10	13 to 22	23 to 44	29 to 60
Switching from 70% effective full dose
1.0 (70%)	0	20 to 35	30 to 52	35 to 64
0.8 (65%)	−6 to −3	18 to 31	27 to 45	33 to 57
0.4 (49%)	−27 to −13	−1 to 15	17 to 32	24 to 40
0.2 (34%)	−52 to −24	−26 to −5	−12 to 12	−3 to 21

Values are $1-(\#\mathit{deaths} \mathit{with} \mathit{fractional} \mathit{dose}/\#\mathit{deaths} \mathit{with} \mathit{standard} \mathit{dose})$. Ranges correspond to different epidemic scenarios (SI Appendix, section 2) from R = 0.99 to R = 2. Positive values (in bold) favor switching to the lower dose. Vaccination rate is proportional to reciprocal of dose. The standard dose (“dose = 1”) column is included for comparison with fractional doses and to illustrate the magnitude of additional burden of mortality due to various levels of loss of efficacy.