The partisan gap, measured by deaths above what would normally be expected, was particularly stark during last year’s Delta wave, when all adults had access to vaccines but stark differences emerged between Democrats and Republicans’ vaccination rates.

The gap shrank during the Omicron wave, as the variant could evade some of the vaccines’ protection.

In the pre-vaccine phase of the pandemic, blue states — particularly big cities — were hit hardest beginning in March 2020. But once those initial outbreaks subsided, the virus took off in red states and less populated areas.

The big picture: The virus has proved itself to be exhaustingly unpredictable in many ways over the last two years. But there’s no doubt that tools like high-quality masks and vaccines reduce the risk of catching the virus, and in the case of vaccines, of dying from it.