I received my last dose of Pfizer in May but I have decided to be a human experiment and get the Moderna as well which I have had one shot of so far a few days ago. No side effects so far. Just walked into Walmart told them I didn't have insurance, got the shot and appointment for the next one.
Is there some benefit you are hoping to achieve by getting two different mRNA vaccines? I was under the assumption they both worked about the same?
I don't believe they work the same because with this new Delta variant they are saying Moderna is better and not Pfizer. If they were really the same then the effectiveness should be the same with each variant.
If he doesn't end up frying or bursting his lymph nodes, it'll all just be "harmless" immune system training.