Fig. 5.

Simulated effect of phased pandemic influenza vaccination for homologous and heterologous vaccines at different levels of R₀ and coverage for USA. A. Vaccine coverage over time with a 30 day delay. Vaccine is delivered at a rate of 120 million doses each month or about 20% coverage per month. This is enough vaccine to give 60 million people with two doses, three weeks apart per month. Vaccine is delivered uniformly over the month. Day 0 is the beginning of pandemic H1N1 spread in the USA. When there is no delay in vaccine supply, vaccination would start on day 0. The dotted lines show the coverage for a strategy to vaccinate children first (red line) and then adults (blue line) starting when coverage reaches 70% in children. B. Epidemic curves when R₀ = 1.6 for homologous and heterologous vaccines, delivered with a 30 day delay. Both universal and the children first vaccination strategies are shown. C. Overall illness attack rates for homologous vaccine for the universal and child first vaccination strategies, both with and without the 30 day delay. D. Overall illness attack rates for heterologous vaccine for the universal and children first vaccination strategies, both with and without the 30 day delay.