OBJECTIVES

During the early COVID-19 pandemic (2020 to mid-2021), the Philippine government relied on nonpharmaceutical interventions such as lockdowns and Enhanced Community Quarantine (ECQ). With the emergency use authorization of vaccines, assessing their potential impact became essential. This study develops a Philippine model to evaluate the epidemiologic and economic effects of COVID-19 vaccination, estimating its impact on mortality, hospitalization, and mild/asymptomatic cases under various prioritization strategies, including booster doses and the presence of variants of concern.

METHODS

A dynamic transmission model (DTM) with an SEIR (Susceptible-Exposed-Infected-Recovered) structure was calibrated using local data, including case numbers, deaths, seroprevalence, vaccination coverage, and intervention costs. The model’s outputs informed a cost-effectiveness analysis (CEA) from health system and societal perspectives over a two-year horizon. Incremental Cost-Effectiveness Ratios (ICERs) were calculated, with costs adjusted to 2020 prices and discount rates of 3%-10% applied. Sensitivity analyses, including one-way and probabilistic approaches, assessed robustness, while a budget impact analysis (BIA) estimated government expenditures in 2020 and 2021.

RESULTS

Without vaccination, daily cases could have peaked at 400,000 between February and May 2021. A vaccination campaign was projected to reduce cases to around 20,000, significantly lowering mortality.  

From the health system perspective, the estimated cost without vaccination was PhP 14.46 trillion, with 93.83 million QALYs. With vaccination, costs dropped to PhP 2.36 trillion, while QALYs increased to 101.79 million. From the societal perspective, costs were PhP 14.68 trillion without vaccination and PhP 2.38 trillion with vaccination, with the same QALY outcomes.

CEA results confirmed that vaccination was cost-saving, with ICERs of -PhP 1,520,727.28 per QALY (health system) and -PhP 1,546,171.63 per QALY (societal). Sensitivity analyses supported these findings, with oneway sensitivity analysis showing minimal impact from parameter changes and probabilistic sensitivity analysis confirming cost-saving outcomes. The BIA estimated government expenditures of PhP 983.45 billion in 2020 and PhP 1.47 trillion in 2021 for the vaccine scenario, lower than the no-vaccine scenario.

CONCLUSION

Indeed, our modeling has shown that COVID-19 vaccines could mitigate the spread of COVID-19 and provide good value for money.

Human ; Covid-19 ; Cost-effectiveness Analysis ; Vaccines ; Philippines

A 48-year-old caucasian male was admitted to hospital with right-sided chest pain, pyrexia and cough. He had no history of dysentery. He was treated with erythromycin and cotrimoxazole for right lower lobe pneumonia but failed to respond. Tender hepatomegaly developed and ultrasound scan demonstrated multiple abscesses in the liver. Entamoeba histolytica was identified in his faeces. He was treated with intravenous metronidazole, chloramphenicol and gentamicin and then oral tinidazole, after which improvement was rapid. He was later transferred to Australia. Subsequent abdominal CAT scan and aspiration of abscesses confirmed the diagnosis of multiple amoebic liver abscesses with secondary bacterial infection. Final treatment was with oral ciprofloxacin and metronidazole for four weeks. Ultrasonography is a noninvasive technique which is invaluable in the diagnosis of abdominal and especially liver pathology. This technique should be available in larger centres in tropical countries. Anyone living in or visiting the tropics should be aware of possible exotic diseases presenting in unusual ways.
Anti-Bacterial Agents - therapeutic use ; Antitrichomonal Agents - therapeutic use ; Liver Function Tests