Modeling the potential public health impact of different vaccination strategies with an omicron-adapted bivalent vaccine in Malaysia

Figures & data

Figure 1. Model structure. The Markov component (top) and decision tree component (bottom) of the model are shown. Abbreviations: ICU = intensive care unit; PASC = post-acute sequelae of COVID-19.

Table 1. Base case results and expanding vaccination to other age and risk groups.

	Base Case: Age ≥65 Years and High Risk			Age >55 Years and High Risk			Age >55 Years, Age 6 Mo-5 Years, and High Risk
	No Vaccination	Vaccination	Incremental Impact	No Vaccination	Vaccination	Incremental Impact	No Vaccination	Vaccination	Incremental Impact
Vaccine doses administered	0	5,469,261	5,469,261	0	5,992,760	5,992,760	0	6,576,703	6,576,703
Deaths	13,387	10,953	2,434	13,387	10,795	2,593	13,475	10,875	2,600
Hospitalizations	347,084	313,855	33,229	347,084	310,486	36,598	375,536	336,527	39,009
Infections	5,031,118	4,756,805	274,313	5,031,118	4,733,676	297,442	5,320,001	5,001,249	378,751
Direct medical costs (million MYR)	8,387	7,811	576	8,387	7,757	630	8,953	8,280	672
Testing cost (million MYR)	1,268	1,209	59	1,268	1,204	64	1,340	1,272	69
AE management cost	0	149,908	−149,908	0	164,256	−164,256	0	180,262	−180,262
Inpatient treatment cost (million MYR)	3,603	3,256	347	3,603	3,220	382	3,895	3,488	407
Outpatient treatment cost (million MYR)	815	773	347	815	769	382	860	811	407
Post-COVID condition treatment cost (million MYR)	2,702	2,574	128	2,702	2,563	139	2,858	2,709	148
Indirect costs (million MYR)	11,584	11,006	579	11,584	10,957	628	11,585	10,957	629
Productivity loss due to illness (million MYR)	11,409	10,835	574	11,409	10,786	623	11,409	10,786	623
Productivity loss due to death (million MYR)	11	9	2	11	9	2	11	9	2
Education loss (million MYR)	164	161	3	164	161	3	164	161	3

*Base case coverage in the high-risk population: 0% (5–11 years), 1.5% (12–17 years), 58.2% (18–29 years), 69.3% (30–54 years), 73.6% (55–64 years), 72.6% (65–74 years), and 61.9% (≥75 years)

Abbreviations: AE = adverse event, MYR = Malaysian ringgit.

Table 2. Scenario analysis results expanding vaccination in the standard-risk population compared to base case of Age ≥65 and High Risk.

	Base case: Age ≥ 65and High Risk*	Standard RiskCoverage: 25%	Standard RiskCoverage: 50%	Standard RiskCoverage: 75%
Vaccine doses administered	5,469,261	10,811,476	16,153,691	21,495,905
Deaths averted	2,434	2,684	2,935	3,185
Hospitalizations averted	33,229	50,385	67,541	84,698
Infections averted	274,313	537,856	801,399	1,064,942
Direct medical costs averted (million MYR)	576	972	1,368	1,765
Indirect costs averted (million MYR)	579	1,121	1,663	2,205

*Base case coverage: low-risk population: 0% (5–64 years), 72.6% (65–74 years), and 61.9% (≥75 years); high-risk population: 0% (5–11 years), 1.5% (12–17 years), 58.2% (18–29 years), 69.3% (30–54 years), 73.6% (55–64 years), 72.6% (65–74 years), and 61.9% (≥75 years)

Standard-risk population comprises individuals with no comorbidities.

Abbreviations: MYR = Malaysian ringgit.

Table 3. Scenario analysis results expanding vaccination in the standard-risk population compared to base case of Age ≥55 and High Risk.

	Base case: Age > 55and High Risk*	Standard RiskCoverage: 25%	Standard RiskCoverage: 50%	Standard RiskCoverage: 75%
Vaccine doses administered	5,992,760	11,157,203	16,321,646	21,486,089
Deaths averted	2,593	2,789	2,986	3,182
Hospitalizations averted	36,598	52,610	68,622	84,634
Infections averted	297,442	553,131	808,819	1,064,508
Direct medical costs averted (million MYR)	630	1,008	1,386	1,764
Indirect costs averted (million MYR)	628	2,161	3,065	3,968

*Base case coverage: low-risk population: 0% (5–64 years), 72.6% (65–74 years), and 61.9% (≥75 years); high-risk population: 0% (5–11 years), 1.5% (12–17 years), 58.2% (18–29 years), 69.3% (30–54 years), 73.6% (55–64 years), 72.6% (65–74 years), and 61.9% (≥75 years)

Standard-risk population comprises individuals aged 5–54 years with no comorbidities.

Abbreviations: MYR = Malaysian ringgit.

Table 4. Scenario analysis results expanding vaccination in the standard-risk population compared to base case of Age 6 mo-4 years or > 55 and High Risk.

	Base case: Age 6 mo-4 yearsor >55 years and High Risk*	Standard RiskCoverage: 25%	Standard RiskCoverage: 50%	Standard RiskCoverage: 75%
Vaccine doses administered	6,576,703	11,741,146	16,905,589	22,070,031
Deaths averted	2,600	2,796	2,993	3,190
Hospitalizations averted	39,009	55,021	71,033	87,045
Infections averted	378,751	575,440	830,128	1,085,817
Direct medical costs averted (million MYR)	672	1,050	1,428	1,806
Indirect costs averted (million MYR)	1,301	2,204	3,107	4,011

*Base case coverage: low-risk population: 25% (6 months-4 years), 0% (5–64 years), 72.6% (65–74 years), and 61.9% (≥75 years); high-risk population: 25% (6 months-4 years), 0% (5–11 years), 1.5% (12–17 years), 58.2% (18–29 years), 69.3% (30–54 years), 73.6% (55–64 years), 72.6% (65–74 years), and 61.9% (≥75 years)

Standard-risk population comprises individuals aged 5–54 years with no comorbidities.

Abbreviations: MYR = Malaysian ringgit.

Table 5. Scenario analysis results varying the disease burden in the base-case analysis of the high-risk population.

	Wave 1 (Alpha Variant)	Wave 2 (Delta Variant)	Base Case: Wave 3 (Omicron Variant)
Vaccine doses administered	5,469,261	5,469,261	5,469,261
Deaths averted	436	9,740	1,446
Hospitalizations averted	13,270	45,497	21,799
Infections averted	30,473	195,947	274,371
Direct medical costs averted (million MYR)	163	633	458
Indirect costs averted (million MYR)	70	523	573

Wave 3 served as the base case.

Wave 1 (Alpha variant) was between January 2021 and March 2021, Wave 2 (Delta variant) was between July 2021 and September 2021, and Wave 3 (Omicron variant) was between January 2022 and March 2022.

High-risk population comprises individuals with at least one comorbidity and individuals aged ≥65 years.

Abbreviations: MYR = Malaysian ringgit.

Figure 2. One-way deterministic sensitivity analysis. Tornado diagram showings the top 25 parameters with the greatest impact on the results.