Cost-effectiveness of vaccinating pregnant women against pandemic influenza in Colombia

Objective. Estimating the cost-effectiveness ratio of vaccinating pregnant women against the 2009 pandemic influenza A (H1N1) in Colombia during the second wave of the pandemic. Methods. A decision tree was constructed, which simulated the health results (deaths and years of potential life lost [YPLL]) in two cohorts of pregnant women; one vaccinated, the other unvaccinated. The model's parameters were drawn from scientific literature and costs were estimated on the basis of a previous study. Incremental cost-effectiveness ratios (ICER) were calculated. Results. Vaccinating pregnant women against pandemic flu would have prevented between 4 664 and 15 741 outpatient visits and between 119 and 401 hospitalizations. Between US$ 249 530 and US$ 842 163 in costs of care would have been avoided. For the base scenario, vaccinating pregnant women would be cost-effective (ICER/YPLL avoided US$ 7 657). This ICER was responsive to the disease's fatality rate; vaccination would not be cost-effective in Colombia in scenarios with a lower fatality rate. Conclusions. Vaccinating pregnant women against pandemic influenza is cost-effective in a scenario with a high mortality rate. The existing evidence that pregnant women are at increased risk of complications and that the vaccine is safe would justify its use in pregnant women.