Rabbi Dr. Mordechai Halperin, director of The Schlesinger Institute for Medical-Halachic Research said on Kan Moreshet that vaccines on Shabbat are a matter of life and death.
"If we are convinced that there is no intention to desecrate Shabbat, then yes, get vaccinated on Shabbat. Including going to the clinic on Shabbat."
The Schlesinger Institute was founded in Israel in 1966 under the auspices of Shaare Zedek Medical Center.