No vaccinations really until January and the steep drop off began early January. 133 million vaccines administered, probably 25% immune, another 50 plus million cases even though only 30 million reported. We are probably over 50% now closing in on 60% and need only 70 for herd immunity, real close.
Time will tell if the vaccines confer long term immunity. But maybe that won’t be needed if it just buys enough time for the virus to run out of hosts. So far so good. But there is a reason they have to give 2 shots, and talk about a booster shot. I suspect the vaccine makers have some doubts about the lasting effects of these vaccines - which they should since they only have a limited set of data to work with. Hopefully it will last like natural immunity should.
According to the OP, the samples they tested showed roughly 4x more people had antibodies than the reported numbers of infected. So perhaps you (we) have underestimated natural immunity rates.