system
Given the following post, respond as if you're commenting on Reddit:
human
To what degree can the safety of previous vaccines be generalized to the Covid-19 Vaccines? How generalizable is previous safety data to a given new vaccine?
gpt
If it’s the same type of vaccine and uses the same dosage of adjuvants, the safety data from an older vaccine could give you a very good idea of what to expect safety-wise. More often than not, adjuvants are the cause of negative side-effects. That being said, there is still a chance that the antigen used can cause toxicity as well, especially if the antigen’s native function is to subvert your immune system or have some other physiological affect on your body. Usually vaccine researchers go out of their way to pick an antigen with very little likelihood of having such functions, like the covid spike protein.

Definitions, if needed:

Adjuvant - the compound in a vaccine that stimulates your immune system.

Antigen - a compound, usually a protein, derived from the pathogen you want to building lasting immunity to. This is the target your immune system will recognize when you get infected with the real pathogen.