1.Forecasting the effects of vaccination on the COVID-19 pandemic in Malaysia using SEIRV compartmental models
Mei Cheng LIM ; Sarbhan SINGH ; Chee Herng LAI ; Balvinder Singh GILL ; Mohd Kamarulariffin KAMARUDIN ; Ahmed Syahmi Syafiq MD ZAMRI ; Cia Vei TAN ; Asrul Anuar ZULKIFLI ; Mohamad Nadzmi Md NADZRI ; Nur'ain MOHD GHAZALI ; Sumarni MOHD GHAZALI ; Nuur Hafizah MD IDERUS ; Nur Ar Rabiah Binti AHMAD ; Jeyanthi SUPPIAH ; Kok Keng TEE ; Tahir ARIS ; Lonny Chen Rong Qi AHMAD
Epidemiology and Health 2023;45(1):e2023093-
OBJECTIVES:
This study aimed to develop susceptible-exposed-infectious-recovered-vaccinated (SEIRV) models to examine the effects of vaccination on coronavirus disease 2019 (COVID-19) case trends in Malaysia during Phase 3 of the National COVID-19 Immunization Program amidst the Delta outbreak.
METHODS:
SEIRV models were developed and validated using COVID-19 case and vaccination data from the Ministry of Health, Malaysia, from June 21, 2021 to July 21, 2021 to generate forecasts of COVID-19 cases from July 22, 2021 to December 31, 2021. Three scenarios were examined to measure the effects of vaccination on COVID-19 case trends. Scenarios 1 and 2 represented the trends taking into account the earliest and latest possible times of achieving full vaccination for 80% of the adult population by October 31, 2021 and December 31, 2021, respectively. Scenario 3 described a scenario without vaccination for comparison.
RESULTS:
In scenario 1, forecasted cases peaked on August 28, 2021, which was close to the peak of observed cases on August 26, 2021. The observed peak was 20.27% higher than in scenario 1 and 10.37% lower than in scenario 2. The cumulative observed cases from July 22, 2021 to December 31, 2021 were 13.29% higher than in scenario 1 and 55.19% lower than in scenario 2. The daily COVID-19 case trends closely mirrored the forecast of COVID-19 cases in scenario 1 (best-case scenario).
CONCLUSIONS
Our study demonstrated that COVID-19 vaccination reduced COVID-19 case trends during the Delta outbreak. The compartmental models developed assisted in the management and control of the COVID-19 pandemic in Malaysia.