I remember reading that autoimmune diseases are more common in people descended from regions that survived the bubonic plague, and that it’s believed this is because the survivors of the plague had mutations which meant they had a more active immune system.
That's the neat thing, it doesn't have to. Every kWh that goes into these batteries is a kWh not purchased from the grid. The payback for the solar panels would very quickly add up.
In fact, trying to 100% charge the batteries via solar would not be the most economical way to operate as then you are just wasting money sending power back to the grid.
“Effectiveness” was a measurement of reduction in severe infection, not reduction of transmissibility. Nobody ever claimed there was a 90% reduction in transmission.
The Treasury (under the executive branch) could possibly regulate crypto as a currency, but most likely this would require new legislation from congress to give the Treasury the power to do so.