New booster aims to shield the vulnerable from COVID-19

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Male, female or transgender, ≥ 18 years old at Day 0. * Provide inform consent form * Participant who has: * 3 doses of mRNA vaccines * 2 doses of mRNA vaccines and previous COVID-19 infection * 2 doses of Coronavac and 1 Comirnaty, or, 1 Coronavac and 2 Comirnaty * Participant who has: * HIV infection with CD4 Tcells counts \<400 * Primary antibody deficiency disorders * Kidney disease on dialysis * Kidney transplant at least \>1 year * Auto Immune Disease (AID) in treatment with rituximab * For a female of childbearing potential, to have a negative pregnancy test at Day 0 * Use of any of these contraception: * Female: hormonal contraception, intrauterine device, vasectomized partner, sexual abstinence, condom. * Male: Vasectomized participant, sexual abstinence, condom. Exclusion Criteria: * History of anaphylaxis to any prior vaccine * Participants has received or plans to receive live attenuated vaccines, other not live vaccines, or Vaxzevria or Janssen vaccines. * Pregnant or breast-feeding at Day 0. * A confirmed COVID-19 diagnose \<90 days prior to vaccination day 0. * A clinically significant acute illness or fever at screening or 48h before day 0. * Participant had a surgery requiring hospitalisation and has not received the hospital discharge. * Participant has an ongoing severe and non-stable psychiatric condition * Participant has a problematic or risky use of substances including alcohol * Participant has a bleeding disorder that contraindicates intramuscular injection * Participant suffering from post-acute COVID-19 syndrome / long COVID * Participant received any immunotherapy to prevent/treat COVID-19 in the last 90 days * Participant is already participating in another research involving drug, biologics or device * Participant has donated ≥450 ml of blood products within 12 weeks before screening * Participant has any medical condition and/or finding that in the investigator opinion might increase participant risk, interfere with the study or impair interpretation of study data.