Which arm you choose when getting a vaccine matters, study shows
If you’re planning on getting the COVID-19 booster this fall, think back on when you received your original shot: In which arm was it administered?
Your immune response might be stronger if your booster goes in the same arm as your COVID-19 shot, according to a study published in the journal eBioMedicine and reported by CNN.
“The question seems so banal, so trivial that nobody before has thought to ask it,” study coauthor Martina Sester, a biologist and head of the department of the Institute of Infection Medicine at Saarland University Hospital in Germany, said in a news release.
The study analyzed data from 303 people who received the mRNA vaccine as well as a booster shot. It showed the number of “killer T cells” needed to fight the virus was higher in those who had both shots in the same arm, found in 67% in those who had shots in the same arm vs. 43% for those who didn’t.
Another theory, researchers said, is that the vaccine in the same arm targets the same lymph nodes and makes them better at fighting off infections.