Are the antibodies developed by differing vaccines still the same?
Due to the nature of the immune system, even people who receive the same vaccine will have a different set of antibodies.
Our immune systems generate a vast number of essentially random recognition combinations, unique to every individual. This leads to a polyclonal response to both infections and vaccines, involving multiple antibodies and the fine details of those antibodies differ based on the specific antibodies in the &quot;library&quot; that the person's body has generated.
Now, different antigens do result in different antibodies being selected for, so one might expect there to be additional differences due to getting an mRNA coding for a SARS-CoV-2 spike protein vs. getting a whole inactivated virus. There's a reason that the spike protein is the preferred target, however, in that its position on the outside of the virus leads it to be a focal point for the response to an inactivated virus.
Bottom line: the responses will differ, but will likely always have a varied set of antibodies targeting the spike protein in any case.