His innovative research has a direct effect on the two most pivotal decisions of flu shot design. One is its composition. WHO recommends which flu strains to include in the annual vaccine. A poor match between the selected virus strains and the ones that emerge during the season can reduce the vaccine’s effectiveness by half. The other decision is the timing. WHO has to make both the composition and timing decisions at least six months before the flu season starts. Selecting the strains too early with insufficient data increases the odds of there being a mismatch. But, delaying the decision will impact production lead times, resulting in delays or shortages in the flu shot supply. Production timing and availability can be the difference between life and death.