Are you right-handed or left-handed? Healthcare professionals often choose the opposite side to administer a vaccination. In case of pain or redness at the injection site, the patient can continue their daily life without hindrance thanks to their "dominant" arm. In the case of a booster, the choice of the arm to be vaccinated would be of great importance. By vaccinating in the same arm as for the first injection, the immune response would be faster and more effective, according to recent work published in the journal Cell.
Many factors influence the effectiveness of a vaccine: the base used to deliver the immunogen, how the immunogen was designed, the formulation, the adjuvants used, individual variations in the injection, the routes of administration, the number of vaccine doses, and the intervals between doses. Now, the arm used also plays a role.
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