Document text
Economic analysis of an
additional dose of COVID -19 vaccine
University of Michigan
COVID -19 Vaccination Modeling Team
Model updates & additional analysis
February 2024
1
Study team
University of Michigan
•Lisa A. Prosser, PhD, Principal Investigator
•David W. Hutton, PhD, Co -Investigator
•Acham Gebremariam, MS, Programmer/Analyst
•Angela Rose, MS, MPH, Project Manager
•Kerra Mercon, MS, Research Assistant
Wake Forest University
•Cara Janusz, PhD
Additional contributors to 2021 Covid Vaccination Model:
Marisa Eisenberg, Emily Martin, Grace Chung, Janamarie
Perroud, Ellen Kim Deluca, Chris Cadham, Huey -Fen Chen,
Anton L.V. Avancena, Tran Doan, David SuhCenters for Disease Control and Prevention
•Jamie Pike, PhD, Health Economist, Project officer
•Megan Wallace, DrPH, Epidemiologist
•Ismael Ortega -Sanchez, PhD, Senior Economist
•Andrew Leidner, PhD, Economist
•Fangjun Zhou, PhD, Health Scientist
•Melisa Shah, MD, MPH, Medical Epidemiologist
•Danielle Moulia, MPH, Health Scientist
•Ruth Link -Gelles, PhD, Epidemiologist
•Sharon Saydah, PhD, Epidemiologist
2
Conflict of interest statement
3Authors have no known conflicts of interest.
Objectives
•Original aims*:
oEstimate annual disease burden and healthcare utilization associated with COVID -19
illness and COVID -19 booster vaccination, including cases of symptomatic illness,
hospitalizations, deaths, adverse events, costs, and quality -adjusted life years
oProject cost -effectiveness of an updated mRNA booster against COVID -19-associated
illness in persons ages ≥18 years
•Update s to the current version of the model:
oProbability of hospitalization: Oct 2022 -Sept 2023
oAdjusted vaccine impact: seasonality
o2-dose strategy (an additional mid -year dose)
4* An earlier analysis from this model was presented to ACIP on September 12, 2023: Prosser, Lisa A. (2023). Economic Analysis o f Vaccination with mRNA Booster Dose
against COVID -19 Among Adults.
Weekly rates of COVID -19 associated
hospitalizations by season, all ages
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2021 -2022
Annual probability of hospitalization, by age
Updated to COVID -NET data from Oct 2022 -Sept 2023 (table)
Age group Base caseRange
Low High*
18-49 y 44 10 204
50-64 y 155 41 479
65+ y 790 245 2090
Source: COVID -NET05001000150020002500
18-49 years 50-64 years 65+ yearsAnnual hospitalizations per 100,000
Sept 2023 model Updated Feb 2024 model
6*Adjusted to include upper limit from Oct 22 -Mar 23
Note: Table provides values for updated February 2024 model,
reflects rates for patients hospitalized due to COVID -19 as a
primary diagnosis
Seasonality -adjusted vaccine impact, 1 -dose strategy
61%
46%
22%
0%20%40%60%80%100%
0 73 146 219 292 365Vaccine Efficacy Against Hospitalization1st dose
020406080100120140
1 2 3 4 5 6 7 8 9 10 11 12Hospitalizations per 100,0001st dose
Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep All adults (18+ y) 65+ y only
7Source: COVID -NET, VISION, and IVY
02468101214161820
1 2 3 4 5 6 7 8 9 10 11 12Critical illness
per 100,000
020406080100120140
1 2 3 4 5 6 7 8 9 10 11 12Hospitalizations
per 100,000Seasonality -adjusted vaccine impact, 1 -dose strategy,
65+ y
8
1st dose
1st doseHospitalizations Critical illness
Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep
Source: COVID -NET, VISION, and IVY
Seasonality -adjusted vaccine impact, 2 -dose strategy,
65+ y
02468101214161820
1 2 3 4 5 6 7 8 9 10 11 12Critical illness
per 100,0002nd
dose1st
dose
9020406080100120140
1 2 3 4 5 6 7 8 9 10 11 12Hospitalizations
per 100,0002nd
dose1st
dose
Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Hospitalizations Critical illness
Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep
Source: COVID -NET, VISION, and IVY
Updated VE and seasonality -adjusted vaccine impact
Health outcomesSeptember 2023 analysis
VEFebruary 2024 analysis*
Seasonality -adjusted vaccine
impact
AgeBase
caseLow High AgeBase
caseLow High
1-dose
strategy•Symptomatic illness (non -
hospitalized)
•Hospitalization, uncomplicatedPooled
18+ y 0.269 0.088 0.418 65+ y 0.347 0.134 0.468
•Critical illness**
•DeathPooled
18+ y 0.403 0.191 0.671 65+ y 0.451 0.272 0.666
2-dose
strategy•Symptomatic illness (non -
hospitalized)
•Hospitalization, uncomplicatedPooled
18+ y 0.428 0.176 0.505 65+ y 0.434 0.179 0.509
•Critical illness**
•DeathPooled
18+ y 0.552 0.382 0.672 65+ y 0.549 0.386 0.669
Source: COVID -NET, VISION, and IVY* Updated hospitalization rates Oct 22 - Sept 23, seasonality -adjusted vaccine impact
**Hospitalization requiring ICU and/or ventilator assistance
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Additional assumptions: 2 -dose strategy
•Adverse events: Twice the number of the 1 -dose strategy
•Costs of vaccination: Twice the cost of the 1 -dose strategy
•See supplementary slides 32 -33
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Analysis Plan
•Updated analysis : Calculate incremental cost -effectiveness ratios comparing
updated mRNA booster (1 -dose strategy) to no booster, using updated
hospitalization and seasonality -adjusted vaccine impact
•Second dose : Conduct base case and uncertainty analyses (one -way sensitivity
and scenario analyses) comparing no booster, 1 -dose, and 2 -dose strategies
•Project disaggregated outcomes stratified by intervention strategy and by age
subgroups (18 -49y, 50 -64y, 65+y) – supplemental slides
oCases
oHospitalizations
oDeaths
oCosts
oQALYs
oAdverse events
***This presentation reports preliminary results from the second phase of an ongoing analysis***
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Results
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Incremental cost -effectiveness ratios (ICERs),
comparison to September 2023 analysis, societal
perspective, preliminary results
Age Intervention strategyICER
($/QALY)
September 2023 analysisICER
($/QALY)
February 2024 analysis
18-49 yNo updated COVID -19 vax - -
Updated COVID -19 vax, 1 -dose strategy $115,588 $163,255
50-64 yNo updated COVID -19 vax - -
Updated COVID -19 vax, 1 -dose strategy $25,787 $80,427
65+ yNo updated COVID -19 vax - -
Updated COVID -19 vax, 1 -dose strategy Cost -saving $11,936
14QALY = quality -adjusted life year
Incremental cost -effectiveness ratios (ICERs),
adding a 2 -dose strategy, societal perspective,
preliminary results
Age group Intervention strategyICER
($/QALY)
18-49 yNo updated vax -
Updated Covid -19 vax, 1 -dose strategy $163,255
Updated Covid -19 vax, 2 -dose strategy $1,317,714
50-64yNo updated vax -
Updated Covid -19 vax, 1 -dose strategy $80,427
Updated Covid -19 vax, 2 -dose strategy $777,612
65+ yNo updated vax -
Updated Covid -19 vax, 1 -dose strategy $11,936
Updated Covid -19 vax, 2 -dose strategy $255,122
15QALY = quality -adjusted life year
ICERs, 1 -way sensitivity analysis,
probability of hospitalization, societal perspective,
preliminary results
*Probability of hospitalization inputs, base case (range): 18-49 y: 0.000443 (0.000101 - 0.00204); 50 -64 y: 0.00155 (0.000413 - 0.00479);
65+ y: 0.0079 (0.00245 - 0.0209)
ICER = incremental cost -effectiveness ratio; QALY = quality -adjusted life yearAge
groupStrategyICER ($/QALY)
Base case Lower bound Upper bound
18-49 yUpdated Covid -19 vax, 1 -dose strategy $163,255 $195,442 $69,538
Updated Covid -19 vax, 2 -dose strategy $1,317,714 $1,507,831 $807,114
50-64 yUpdated Covid -19 vax, 1 -dose strategy $80,427 $161,605 Cost saving
Updated Covid -19 vax, 2 -dose strategy $777,612 $1,193,501 $349,971
65+ yUpdated Covid -19 vax, 1 -dose strategy $11,936 $81,544 Cost saving
Updated Covid -19 vax, 2 -dose strategy $255,122 $566,141 $80,182
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Alternative season scenarios
17050100150200250300
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
June
July
Aug
SeptHospitalizations per 100,000
18-49 50-64 65+050100150200250300
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
June
July
Aug
SeptHospitalizations per 100,000
18-49 50-64 65+Alternative season #2
(spring peak)
050100150200250300
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
SepHospitalizations per 100,000
18-49 50-64 65+Alternative season #1
(winter peak)Base case
050100150200250300
1 2 3 4 5 6 7 8 9 10 11 12Hospitalizations
per 100,0001st doseSeasonality -adjusted vaccine impact:
alternative season scenario #1 (winter peak)
Health outcomes Age groupSeasonality -adjusted vaccine impact, alternative scenario #1 (winter peak)
1-dose 2-dose
Base Lower Upper Base Lower Upper
Symptomatic illness and
hospitalization65+ years0.334 0.121 0.460 0.443 0.181 0.516
Critical care and death 0.432 0.229 0.657 0.540 0.379 0.660
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2nd dose
Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep
050100150200250300
1 2 3 4 5 6 7 8 9 10 11 12Hospitalizations
per 100,0001st doseSeasonality -adjusted vaccine impact:
alternative season scenario #2 (spring peak)
Health outcomes Age groupSeasonality -adjusted vaccine impact, alternative scenario #2 (spring peak)
1-dose 2-dose
Base Low High Base Low High
Symptomatic illness and
hospitalization65+ years0.269 0.070 0.401 0.439 0.194 0.514
Critical care and death 0.444 0.190 0.670 0.571 0.410 0.688
19050100150200250300
Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept
18-49 50-64 65+
2nd dose
Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep
ICERs, scenario analysis varying seasonality, societal
perspective, preliminary results
20Age
groupIntervention strategyBase case ICER
$/QALYAlternative season #1
(winter peak)
ICER ($/QALY)Alternative season #2
(spring peak)
ICER ($/QALY)
65+ yUpdated Covid -19 vax, 1 -dose strategy $11,936 $14,788 $25,126
Updated Covid -19 vax, 2 -dose strategy $255,122 $198,802 $115,650
ICER = incremental cost -effectiveness ratio; QALY = quality -adjusted life year
ICER, scenario analysis varying probability of
hospitalization*, age 65+, societal perspective,
preliminary results
21Intervention strategyICER ($/QALY)
¼ base case
(198 per 100,000)½ base case
(395 per 100,000)Base case
(790 per 100,000)2x base case
(1580 per 100,000)3x base case
(2370 per 100,000)4x base case
(3160 per 100,000)
Updated Covid -19 vax, 1 -dose $93,904 $52,541 $11,936 Cost saving Cost saving Cost saving
Updated Covid -19 vax, 2 -dose $624,028 $433,533 $255,122 $120,341 $64,599 $34,133
*Adjusted risk of hospitalization by underlying condition: chronic obstructive pulmonary disease: 0.9, history of stroke: 0.9 , coronary artery
disease: 1.3, asthma: 1.4, hypertension: 2.8, obesity: 2.9, diabetes: 3.2, chronic kidney disease: 4.0, severe obesity: 4.4. Ko et al 2021.
ICER = incremental cost -effectiveness ratio; QALY = quality -adjusted life year
ICER, scenario analyses varying vaccination costs,
age 65+, societal perspective, preliminary results
Intervention strategyICER ($/QALY)
$20 $60 Base case $120
Updated Covid -19 vax, 1 -dose strategy Cost saving Cost saving $11,936
Updated Covid -19 vax, 2 -dose strategy $72,240 $145,393 $255,122
Intervention strategyICER ($/QALY)
All lower Base case All upper
Updated Covid -19 vax, 1 -dose strategy Cost saving $11,936 $53,251
Updated Covid -19 vax, 2 -dose strategy $50,768 $255,122 $443,059Varying vaccine dose cost only
Varying all vaccination -related costs*
22*Multi -way sensitivity analysis varying vaccine dose cost, vaccine administration cost, time costs of vaccination, and cost of
vaccine -associated adverse events to lower and upper bounds. See supplementary slides 32 -33 for input data.
ICER = incremental cost-effectiveness ratio; QALY = quality -adjusted life year
Limitations
•Unpublished data used to derive key parameters in the model: vaccine effectiveness,
symptomatic illness, probabilities of hospitalization and critical illness
•Data sources vary in representativeness, generalizability
•VE estimates derived from data on bivalent booster
•Few seasons to date to estimate seasonality
•MarketScan data for ages 65+ only includes those with supplemental insurance
•Evidence base for long covid is especially scarce
•Model does not include reduced transmission (conservative approach)
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Summary
•1-dose strategy, updated inputs (hospitalization, seasonality -adjusted VE)
➢Vaccination averts substantial morbidity and mortality as demonstrated through
estimated disaggregated outcomes (supplementary slides)
➢ICERs for 50 -64y and 65+ age groups remain robust to changes in parameter inputs
across plausible ranges (with a few exceptions)
➢ICERs for 18 -49y remain sensitive to changes in parameter inputs; more favorable for
higher VE, higher risk of hospitalization, and critical illness
•2-dose strategy
➢Not economically favorable for 18 -49y or 50 -64y across plausible parameter ranges
➢For 65+ years, ICERs are sensitive to probability of hospitalization, costs, and
seasonality
➢ICERs are more favorable in scenarios with higher risk of hospitalization, lower costs,
and alternate seasonality
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