I came to counter him with a joke, but the downvoters beat me to it. Anyways:

The vaccine is more like going to the gym. We could continue our ancestor's practice of trying to run from lions, which was possibly better adrenaline practice, and even mostly successful. We might not be scientifically certain of the long-term side-effects of going to the gym, but I'll just rely on the gym nonetheless. And good for you going to the gym too!