COVID-19 vaccines make a spike protein that binds to a naturally occurring protein in the body

Most vaccines tend to have adverse responses within 2 months of injection. Why could it be different for COVID-19 vaccines? This simple point may hold the answer. In order to engineer a spike protein that duplicates the viral spike protein, it also needs to bind tightly to ACE-2. Link to papers in comments.

Never before have we made a vaccine that binds …