Abstract
BackgroundAround the world, controlling the COVID-19 pandemic requires national coordination of multiple intervention strategies. As vaccinations are globally introduced into the repertoire of available interventions, it is important to consider how changes in the local supply of vaccines, including delays in administration, may be addressed through existing policy levers. This study aims to identify the optimal level of interventions for COVID-19 from 2021 to 2022 in the Philippines, which as a developing country is particularly vulnerable to shifting assumptions around vaccine availability. Furthermore, we explore optimal strategies in scenarios featuring delays in vaccine administration, expansions of vaccine supply, and limited combinations of interventions.MethodsEmbedding our work within the local policy landscape, we apply optimal control theory to the compartmental model of COVID-19 used by the Philippine government’s pandemic surveillance platform and introduce four controls: (a) precautionary measures like community quarantines, (b) detection of asymptomatic cases, (c) detection of symptomatic cases, and (d) vaccinations. The model is fitted to local data using an L-BFGS minimization procedure. Optimality conditions are identified using Pontryagin’s minimum principle and numerically solved using the forward–backward sweep method.ResultsSimulation results indicate that early and effective implementation of both precautionary measures and symptomatic case detection is vital for averting the most infections at an efficient cost, resulting in >99% reduction of infections compared to the no-control scenario. Expanding vaccine administration capacity to 440,000 full immunizations daily will reduce the overall cost of optimal strategy by 25%, while allowing for a faster relaxation of more resource-intensive interventions. Furthermore, delays in vaccine administration require compensatory increases in the remaining policy levers to maintain a minimal number of infections. For example, delaying the vaccines by 180 days (6 months) will result in an 18% increase in the cost of the optimal strategy.ConclusionWe conclude with practical insights regarding policy priorities particularly attuned to the Philippine context, but also applicable more broadly in similar resource-constrained settings. We emphasize three key takeaways of (a) sustaining efficient case detection, isolation, and treatment strategies; (b) expanding not only vaccine supply but also the capacity to administer them, and; (c) timeliness and consistency in adopting policy measures.Graphic
Highlights
Around the world, controlling the COVID-19 pandemic requires national coordination of multiple inter‐ vention strategies
Optimal control strategies for COVID‐19 in the Philippines Solving the stated optimal control problem in Eqs. 2–4 generates the optimal levels of precaution ( u1 ), asymptomatic detection ( u2 ), symptomatic detection ( u3 ), and vaccination ( u4 ) over the 2-year period from January 1, 2021 to December 31, 2022 (Fig. 3)
In the Philippines, where long-term states of community lockdown have prevailed as the government’s response to shortterm fluctuations in COVID-19 cases [39], our findings suggest that an optimal, cost-effective strategy would entail relaxations to such measures—but only under the condition that symptomatic case detection is properly implemented
Summary
Around the world, controlling the COVID-19 pandemic requires national coordination of multiple inter‐ vention strategies. As vaccinations are globally introduced into the repertoire of available interventions, it is impor‐ tant to consider how changes in the local supply of vaccines, including delays in administration, may be addressed through existing policy levers. We explore optimal strategies in scenarios featuring delays in vaccine administration, expansions of vaccine supply, and limited combinations of interventions. In the year since the emergence of the global coronavirus disease 2019 (COVID-19) pandemic, national policies have had to decisively manage diverse issues of resource availability, institutional capacity, and collective behavioral change [1,2,3]. Important questions emerge with respect to how governments may adequately adjust existing policies available for pandemic control in relation to multiple scenarios
Sign-in/Register to view highlights & summary 
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call