Economic evaluation of prenatal GBS immunization in China: A modeling analysis

Invasive Group B <i>Streptococcus</i> (GBS) infection is a fatal disease that causes a significant disease burden in young infants worldwide. GBS vaccines being developed are a potential means of preventing GBS; however, their cost-effectiveness in China is unknown. Using a decision analysis model, we simulated the cost-effectiveness of a GBS vaccine for pregnant women compared with no intervention over the lifetime of their newborns from the Chinese healthcare system perspective. We estimate the incremental cost–effectiveness ratio (ICER) and analyzed the impact of uncertainties in key parameters through deterministic sensitivity analysis and probabilistic sensitivity analysis. The vaccine could reduce GBS cases by 49% and yield an ICER of $25,267 per QALY. Based on WTP of 0.5x, 1x, 1.5x, and 3x GDP per capita in 2021, the cost-effective vaccine price would be $23, $37, $51, and $92 per dose, respectively. The results were most sensitive to the cost of the vaccine, GBS incidence, and vaccine efficacy. When the vaccine price is $65, and the vaccine efficacy is 80%, 90% of iterations fell under the $37,663 threshold. When the vaccine price changed to $33, the vaccine is cost-effective under $12,554 (1xGDP per capita) and all iterations fell under $37,663. GBS vaccination is likely to be cost-effective in China at WTP thresholds of $37,663 (3xGDP per capita). Enhancing vaccine efficacy and lowering costs further improve cost-effectiveness. A budget impact analysis will be crucial upon licensure.