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.