Vaccine effectiveness

Because RSV-vaccines are still under development, assumptions had to be made regarding the vaccine effectiveness. As explained above, we considered vaccination at three different moments: during the third trimester of pregnancy, and at 2 and 4 months of age in infants. In our base case scenarios we assumed vaccination coverage of 85% for all vaccinations. The initial vaccine efficacy of vaccination during pregnancy was assumed to be 60%. The first infant dose at 2 months of age was assumed to keep the vaccine effectiveness at 60%. The second infant dose at 4 months of age was assumed to raise the vaccine effectiveness to 75% and provide this level of protection until the date the vaccinated child became 2 years old.

Potential herd protection effects were not included, because of insufficient data to inform and calibrate such a model for Turkey. Moreover, transmission dynamic modelling studies from Kenya indicate that vaccination against RSV during pregnancy or in infants does not likely infer a substantial herd protection effect [36], [37].