Rex Briggs, Founder & Executive Chairman of Marketing Evolution, who had developed forecasts of US COVID infections and deaths early in 2020, before it had been declared a pandemic, talked about the difficulties in “exponential forecasting” of events like a pandemic, compared to “stable state” forecasting of the impact of media, marketing, and creative. Just as companies might not have anticipated the impact of COVID-19 as it spread, they may be caught “flat-footed” in forecasting the exponential decay of the disease as vaccinations spread in 2021. Business forecasts of the impact of COVID in 2021 should take into account vaccination rates by age and surveys on acceptance of the vaccine.