Researchers have found that getting a vaccine booster shot in a different arm from the one you got the first in may improve the body’s immune response up to four-fold. While they exclusively studied responses to the COVID-19 vaccine, they suspect this effect may be seen with other multidose vaccines.
When you get a vaccine, do you have a ‘preferred arm’ that you present to the health professional administering it? Many opt to have vaccines, including booster shots, injected into the same arm, usually to prevent the muscle ache or heaviness that follows from affecting the use of their dominant arm or hand.
Historically, the choice of arm was not thought to matter to vaccine effectiveness. However, a new study by researchers at Oregon Health and Science University (OHSU) has found that when it comes to multidose vaccines, people who have one dose in one arm and the second in the other have an improved immune response.
“This question hasn’t really been extensively studied, so we decided to check it out,” said Marcel Curlin, the study’s corresponding author. “It turned out to be one of the more significant things we’ve found, and it’s probably not limited to just COVID vaccines. We may be seeing an important immunologic function.”