Impact of vaccination and non-pharmacological interventions on COVID-19: a review of simulation modeling studies in Asia

IntroductionEpidemiological modeling is widely used to offer insights into the COVID-19 pandemic situation in Asia. We reviewed published computational (mathematical/simulation) models conducted in Asia that assessed impacts of pharmacological and non-pharmacological interventions against COVID-19 and their implications for vaccination strategy.MethodsA search of the PubMed database for peer-reviewed, published, and accessible articles in English was performed up to November 2022 to capture studies in Asian populations based on computational modeling of outcomes in the COVID-19 pandemic. Extracted data included model type (mechanistic compartmental/agent-based, statistical, both), intervention type (pharmacological, non-pharmacological), and procedures for parameterizing age. Findings are summarized with descriptive statistics and discussed in terms of the evolving COVID-19 situation.ResultsThe literature search identified 378 results, of which 59 met criteria for data extraction. China, Japan, and South Korea accounted for approximately half of studies, with fewer from South and South-East Asia. Mechanistic models were most common, either compartmental (61.0%), agent-based (1.7%), or combination (18.6%) models. Statistical modeling was applied less frequently (11.9%). Pharmacological interventions were examined in 59.3% of studies, and most considered vaccination, except one study of an antiviral treatment. Non-pharmacological interventions were also considered in 84.7% of studies. Infection, hospitalization, and mortality were outcomes in 91.5%, 30.5%, and 30.5% of studies, respectively. Approximately a third of studies accounted for age, including 10 that also examined mortality. Four of these studies emphasized benefits in terms of mortality from prioritizing older adults for vaccination under conditions of a limited supply; however, one study noted potential benefits to infection rates from early vaccination of younger adults. Few studies (5.1%) considered the impact of vaccination among children.ConclusionEarly in the COVID-19 pandemic, non-pharmacological interventions helped to mitigate the health burden of COVID-19; however, modeling indicates that high population coverage of effective vaccines will complement and reduce reliance on such interventions. Thus, increasing and maintaining immunity levels in populations through regular booster shots, particularly among at-risk and vulnerable groups, including older adults, might help to protect public health. Future modeling efforts should consider new vaccines and alternative therapies alongside an evolving virus in populations with varied vaccination histories

Economic Burden of Pneumococcal Infections in Children Under 5Years of Age

The present study aimed to determine the cost of childhood pneumococcal infections under 5years of age and to provide further data for future health economy studies. Electronic medical records of children diagnosed with meningitis caused by S. pneumoniae and all-cause pneumonia, and acute otitis media (AOM) between January 2013-April 2014 were retrospectively evaluated. Direct costs for the treatments of hospitalized patients (pneumonia and pneumococcal meningitis) including costs of healthcare services consisted of costs of hospital bed, examination, laboratory analyses, scanning methods, consultation, vascular access procedures, and infusion and intravenous treatments. Direct costs for patients (AOM) treated in outpatient setting included constant price paid for the examination and cost of prescribed antibiotics. Indirect costs included cost of work loss of parents and their transportation expenses. Data of 130 children with pneumococcal meningitis (n = 10), pneumonia (n = 53), and AOM (n = 67) were analyzed. The total median cost was Euro4,060.38 (direct cost: Euro3,346.38 and indirect cost: Euro829.18) for meningitis, Euro835.91 (direct cost: Euro480.66 and indirect cost: Euro330.09) for pneumonia, and Euro117.32 (direct cost: Euro17.59 and indirect cost: Euro99.73) for AOM. The medication cost (p = 0.047), indirect cost (p = 0.032), and total cost (p = 0.011) were significantly higher in pneumonia patients aged 36 months than those aged <36 months; however, direct cost of AOM were significantly higher in the patients aged <36 months (p = 0.049). Results of the present study revealed that the treatment cost was significantly enhanced for hospitalization and for advanced disease. Thus, preventive actions, mainly vaccination, should be conducted regularly.WoSScopu

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

Background Coronavirus disease 2019 (COVID-19) case numbers have increased following the emergence of the Omicron variant. This study estimated the impact of introducing and increasing the coverage of an Omicron-adapted bivalent booster vaccine in Malaysia. Research Design and Methods A combined cohort Markov decision tree model was used to compare booster vaccination with an Omicron-adapted bivalent COVID-19 vaccine versus no booster vaccination in Malaysia. The model utilized age-specific data from January 2021 to March 2022 derived from published sources. The outcomes of interest included case numbers, hospitalizations, deaths, medical costs, and productivity losses. The population was stratified into high-risk and standard-risk subpopulations, and the study evaluated the benefits of increased coverage in different age and risk groups. Results Vaccinating only high-risk individuals and those aged ≥ 65 years was estimated to avert 274,313 cases, 33229 hospitalizations, 2,434 deaths, Malaysian ringgit (MYR) 576 million in direct medical costs, and MYR 579 million in indirect costs. Expanding vaccination coverage in the standard-risk population to 75% was estimated to avert more deaths (31%), hospitalizations (155%), infections (206%), direct costs (206%), and indirect costs (281%). Conclusions These findings support broader population Omicron-adapted bivalent booster vaccination in Malaysia with potential for significant health and economic gains

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

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing COVID-19 has continuously evolved, requiring the development of adapted vaccines. This study estimated the impact of the introduction and increased coverage of an Omicron-adapted bivalent booster vaccine in Thailand. The outcomes of booster vaccination with an Omicron-adapted bivalent vaccine versus no booster vaccination were estimated using a combined cohort Markov decision tree model. The population was stratified into high- and standard-risk subpopulations. Using age-specific inputs informed by published sources, the model estimated health (case numbers, hospitalizations, and deaths) and economic (medical costs and productivity losses) outcomes in different age and risk subpopulations. Booster vaccination in only the elderly and high-risk subpopulation was estimated to avert 97,596 cases 36,578 hospitalizations, 903 deaths, THB 3,119 million in direct medical costs, and THB 10,589 million in indirect medical costs. These benefits increased as vaccination was expanded to other subpopulations. Increasing the booster vaccination coverage to 75% of the standard-risk population averted more deaths (95%), hospitalizations (512%), infections (782%), direct costs (550%), and indirect costs (687%) compared to the base case. Broader vaccination with an Omicron-adapted bivalent booster vaccine could have significant public health and economic benefits in Thailand.</p

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

Coronavirus disease 2019 (COVID-19) case numbers have increased following the emergence of the Omicron variant. This study estimated the impact of introducing and increasing the coverage of an Omicron-adapted bivalent booster vaccine in Malaysia. A combined cohort Markov decision tree model was used to compare booster vaccination with an Omicron-adapted bivalent COVID-19 vaccine versus no booster vaccination in Malaysia. The model utilized age-specific data from January 2021 to March 2022 derived from published sources. The outcomes of interest included case numbers, hospitalizations, deaths, medical costs, and productivity losses. The population was stratified into high-risk and standard-risk subpopulations, and the study evaluated the benefits of increased coverage in different age and risk groups. Vaccinating only high-risk individuals and those aged ≥ 65 years was estimated to avert 274,313 cases, 33229 hospitalizations, 2,434 deaths, Malaysian ringgit (MYR) 576 million in direct medical costs, and MYR 579 million in indirect costs. Expanding vaccination coverage in the standard-risk population to 75% was estimated to avert more deaths (31%), hospitalizations (155%), infections (206%), direct costs (206%), and indirect costs (281%). These findings support broader population Omicron-adapted bivalent booster vaccination in Malaysia with potential for significant health and economic gains.</p

Modelling the Potential Public Health Impact of Different COVID-19 Vaccination Strategies with an Adapted Vaccine in Singapore

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing COVID-19 has been a dynamically changing virus, requiring the development of adapted vaccines. This study estimated the potential public health impact alternative vaccination strategies for COVID-19 in Singapore. The outcomes of alternative vaccination strategies with a future adapted vaccine were estimated using a combined Markov decision tree model. The population was stratified by high- and standard-risk. Using age-specific inputs informed by local surveillance data and published sources, the model estimated health (case numbers, hospitalizations, and deaths) and economic (medical costs and productivity losses) outcomes in different age and risk subpopulations. Booster vaccination in only the elderly and high-risk subpopulation was estimated to avert 278,614 cases 21,558 hospitalizations, 239 deaths, Singapore dollars (SGD) 277 million in direct medical costs, and SGD 684 million in indirect medical costs. These benefits increased as vaccination was expanded to other subpopulations. Increasing the booster vaccination coverage to 75% of the standard-risk population averted more deaths (3%), hospitalizations (29%), infections (145%), direct costs (90%), and indirect costs (192%) compared to the base case. Broader vaccination strategies using an adapted booster vaccine could have substantial public health and economic impact in Singapore.</p