Abstract:
Background: International analyses suggest that routine maternal vaccination with
seasonal trivalent influenza vaccine is cost-effective, but few studies have been done
in middle- to low- income countries.
Method: A decision-tree analysis was modelled for the South African public
healthcare setting over one year from a payer's perspective. Direct medical costs
and consequences were obtained from published literature. Incremental cost
effectiveness ratios (ICERs) and univariate sensitivity analyses were then measured.
Discounting was excluded due to the seasonality of influenza, limiting the time
horizon to a one year period.
Findings: The model predicted that to avert influenza-associated hospitalisations
amongst pregnant women and their infants less than six months of age, vaccination
of pregnant women was not cost-effective. This was irrespective of whether the
universal vaccination or HIV-targeted approach was used.
A base model simulating 100% vaccine uptake predicted that seasonal vaccination
of 100,000 pregnant women results in an estimated net cost of R69,118,114.05 per
neonatal influenza-associated hospitalisation averted. Similarly, the model
suggested that vaccinating 100,000 pregnant women would cost R1,197,779.79 per
maternal hospitalisation averted.
Univariate sensitivity analyses reinforced that influenza vaccination of pregnant
women was not cost-effective, except when lower incidence of maternal influenzaassociated
hospitalisations associated with antenatal influenza vaccination were simulated where the targeted approach became dominant. The latter analysis
predicted savings of R770,530.86 per maternal influenza-associated hospitalisation
averted.
Interpretation: The ICERs suggest that influenza vaccination amongst pregnant
women is not cost-effective in the South African public healthcare sector compared
to no vaccination, with respect to averting influenza-associated hospitalisations
amongst pregnant women and their infants less than six months of age. However,
these estimates should be re-evaluated, pending vaccine effectiveness studies of
higher methodological quality for low- and middle- income countries and using cost
inputs relevant to South African public healthcare setting. This analysis may provide
preliminary information regarding the upscaling of influenza vaccination amongst
pregnant women as a priority in the constraints of a limited healthcare budget and
careful consideration is required regarding vaccine mobilisation amongst pregnant
women.
