Table 2.

Impact of Variant/Mutation Frequency Among Locally Circulating Viruses and Influence on Efficacy on NNT of Monoclonal Antibodies^a

		Mutation Making mAbs Ineffective		Mutation Making mAbs 50% Less Effective		Mutation Making mAbs 25% Less Effective
Mutation Frequency, %	Not Treated Hospitalization Rate, %	mAb Treated Hospitalization Rate, %	NNT	mAb Treated Hospitalization Rate, %	NNT	mAb Treated Hospitalization Rate, %	NNT
0	7	2	20	2	20	2	20
10	7	2.5	22	2.25	21	2.13	21
20	7	3	25	2.5	22	2.25	21
30	7	3.5	29	2.75	24	2.38	22
40	7	4	33	3	25	2.5	22
50	7	4.5	40	3.25	27	2.63	23
60	7	5	50	3.5	29	2.75	24

Abbreviation: NNT, number needed to treat.

^aTo determine the impact of mutation frequency/effect on monoclonal antibodies, the following process was followed. The 5% absolute difference between treatment and no treatment was multiplied by the mutation frequency (eg, 0.1 for 10%) and the impact the mutation has on efficacy (eg, 0.5 for a 50% decrease in efficacy). The sum of these numbers was then subtracted from the 5% absolute difference to determine the new absolute difference (eg, 5 × 0.1 × 0.5 = 0.25; 5 – 0.25 = 4.75) and then subtracted from the untreated event rate to determine the new event rate for treated patients (eg, 7 – 4.75 = 2.25%). The new absolute difference was then used to calculate the NNT (eg, 100/4.75 = NNT 21).