Trying to predict when we might start seeing vaccinations show up measurably in COVID data is difficult to model. It depends, for instance, on how the demographics of COVID spread match up to the demographics of who is getting the vaccine first. But we can make some guesses.

Vaccinations start to really kick in 3 weeks after first injection (~50% reduction in susceptibility). We'll be 3 weeks past 5% of the US having a first shot on February 14. Assuming a 7-10 day data delay, that suggests we might start seeing a vaccine impact by the end of Feb.

But at the rate we are going (1.1 million vaccines/day, likely up to 1.5 million/day within 2 weeks), basically any American adult who wants a vaccine will get one by early April. So vaccines will be hammering COVID spread well before then. Late-March at the latest, I'd imagine.

There are 209 million American adults. If we assume generously that 60% will go out and seek a vaccine, that's 125 million.

The vaccine model at COVID-19 Projections estimates that we'll get to 125 million first doses on April 4.

And remember: This is the pace we are ALREADY ON. If the Biden Administration can speed up vaccines - as they are promising - this will happen even faster.

There is no excuse to not plan for a fully opened United States this summer.