Which studies?
https://www.miamiherald.com/news/coronavirus/article252185473.html
"studies have found vaccine-derived antibodies are more robust compared to those from natural infection — and the job is done without causing illness or other long-term complications often brought on by the disease.
Two doctors from Italy compared the process of infection and vaccination in relation to variants to the plot of an action movie.
It “begins with a character (the virus) running freely across the globe, eluding capture until being finally sent to jail (built by natural immunity). However, if this prison is not secure enough, the virus could escape, aided by certain mutations,” Dr. Emanuele Andreano and Dr. Rino Rappuoli of the Monoclonal Antibody Discovery Lab, wrote in Nature. “Vaccine-induced immunity… should help ensure those escape routes are securely closed.”
An April study that has not been peer-reviewed found that two doses of either the Pfizer or Moderna vaccines offered 10 times higher levels of antibodies compared to those developed after natural infection.
Another April paper showed that people who were previously infected with the coronavirus experienced significant boosts in their preexisting antibodies after two doses of the Pfizer vaccine, which also offered protection against coronavirus variants."