Thank you for your comment. The association found in this study is indeed a signal to watch out for. I agree data is still limited to conclude if this signal is true or false alarm.

The idea of not using the spike protein to induce immunity may be one solution to mitigating vaccine side effects. But I believe this would be very difficult to achieve. Even in natural infections, it's the antibodies against the spike protein that are mainly responsible for reducing the severity of Covid. Antibodies formed against other parts of the virus, like nucleocapsid or ORF proteins, are not as protective, if I'm not wrong.