TY - JOUR
T1 - Sustaining effective COVID-19 control in Malaysia through large-scale vaccination
AU - Jayasundara, Pavithra
AU - Peariasamy, Kalaiarasu M.
AU - Law, Kian Boon
AU - Abd Rahim, Ku Nurhasni Ku
AU - Lee, Sit Wai
AU - Ghazali, Izzuna Mudla M.
AU - Abayawardana, Milinda
AU - Le, Linh Vi
AU - Khalaf, Rukun K.S.
AU - Razali, Karina
AU - Le, Xuan
AU - Chong, Zhuo Lin
AU - McBryde, Emma S.
AU - Meehan, Michael T.
AU - Caldwell, Jamie M.
AU - Ragonnet, Romain
AU - Trauer, James M.
N1 - Funding Information:
This study was supported by the World Health Organization Regional Office for the Western Pacific and the Australian Medical Research Future Fund’s COVID-19 Rapid Response Digital Health Infrastructure scheme ( RRDHI000027 ). JMT is a recipient of an Early Career Fellowship from the Australian National Health and Medical Research Council ( APP1142638 ). MTM is a recipient of a Discovery Early Career Researcher Award from the Australia Research Council ( DE210101344 ). JMC is funded by the United States National Aeronautics and Space Administration Ecological Forecasting Program ( NNX17AI21G ).
Publisher Copyright:
© 2021
PY - 2021/12
Y1 - 2021/12
N2 - Introduction: As of 3rd June 2021, Malaysia is experiencing a resurgence of COVID-19 cases. In response, the federal government has implemented various non-pharmaceutical interventions (NPIs) under a series of Movement Control Orders and, more recently, a vaccination campaign to regain epidemic control. In this study, we assessed the potential for the vaccination campaign to control the epidemic in Malaysia and four high-burden regions of interest, under various public health response scenarios. Methods: A modified susceptible-exposed-infectious-recovered compartmental model was developed that included two sequential incubation and infectious periods, with stratification by clinical state. The model was further stratified by age and incorporated population mobility to capture NPIs and micro-distancing (behaviour changes not captured through population mobility). Emerging variants of concern (VoC) were included as an additional strain competing with the existing wild-type strain. Several scenarios that included different vaccination strategies (i.e. vaccines that reduce disease severity and/or prevent infection, vaccination coverage) and mobility restrictions were implemented. Results: The national model and the regional models all fit well to notification data but underestimated ICU occupancy and deaths in recent weeks, which may be attributable to increased severity of VoC or saturation of case detection. However, the true case detection proportion showed wide credible intervals, highlighting incomplete understanding of the true epidemic size. The scenario projections suggested that under current vaccination rates complete relaxation of all NPIs would trigger a major epidemic. The results emphasise the importance of micro-distancing, maintaining mobility restrictions during vaccination roll-out and accelerating the pace of vaccination for future control. Malaysia is particularly susceptible to a major COVID-19 resurgence resulting from its limited population immunity due to the country's historical success in maintaining control throughout much of 2020.
AB - Introduction: As of 3rd June 2021, Malaysia is experiencing a resurgence of COVID-19 cases. In response, the federal government has implemented various non-pharmaceutical interventions (NPIs) under a series of Movement Control Orders and, more recently, a vaccination campaign to regain epidemic control. In this study, we assessed the potential for the vaccination campaign to control the epidemic in Malaysia and four high-burden regions of interest, under various public health response scenarios. Methods: A modified susceptible-exposed-infectious-recovered compartmental model was developed that included two sequential incubation and infectious periods, with stratification by clinical state. The model was further stratified by age and incorporated population mobility to capture NPIs and micro-distancing (behaviour changes not captured through population mobility). Emerging variants of concern (VoC) were included as an additional strain competing with the existing wild-type strain. Several scenarios that included different vaccination strategies (i.e. vaccines that reduce disease severity and/or prevent infection, vaccination coverage) and mobility restrictions were implemented. Results: The national model and the regional models all fit well to notification data but underestimated ICU occupancy and deaths in recent weeks, which may be attributable to increased severity of VoC or saturation of case detection. However, the true case detection proportion showed wide credible intervals, highlighting incomplete understanding of the true epidemic size. The scenario projections suggested that under current vaccination rates complete relaxation of all NPIs would trigger a major epidemic. The results emphasise the importance of micro-distancing, maintaining mobility restrictions during vaccination roll-out and accelerating the pace of vaccination for future control. Malaysia is particularly susceptible to a major COVID-19 resurgence resulting from its limited population immunity due to the country's historical success in maintaining control throughout much of 2020.
KW - COVID-19
KW - Mathematical modelling
KW - Vaccination
KW - Variants of concern
UR - http://www.scopus.com/inward/record.url?scp=85118494884&partnerID=8YFLogxK
U2 - 10.1016/j.epidem.2021.100517
DO - 10.1016/j.epidem.2021.100517
M3 - Article
C2 - 34739906
AN - SCOPUS:85118494884
SN - 1755-4365
VL - 37
JO - Epidemics
JF - Epidemics
M1 - 100517
ER -