Same-Arm Vaccine Boosts Immunity Speed, Study Suggests

Sydney — Today — New research suggests that administering a vaccine and booster in the same arm could accelerate immune response.An Australian study, published in cell, examined 30 volunteers, discovering that those receiving both doses in the same arm generated antibodies quicker. This revelation,led by the University of New South Wales,illuminates how the immune system works,offering crucial insights for future vaccine strategies,as cited by a leading immunologist.

Hear’s a rewritten version of the article,focusing on clarity,conciseness,and a more engaging tone:

Health: Same-Arm Vaccine Boosts Immunity Speed,Study Suggests

Published: April 30,2025

Getting your vaccine and booster shot in the same arm might give your immune system a faster kickstart,according too new research.

An Australian study published in the journal cell suggests that injecting both doses of a vaccine into the same arm leads to a quicker antibody response.

Researchers at the University of New South Wales (UNSW) in Sydney studied 30 volunteers who received the Pfizer-BioNTech mRNA COVID-19 vaccine. They found that those who received both doses in the same arm produced antibodies more rapidly than those who switched arms between injections.

The researchers believe this enhanced efficiency is because the first vaccine dose activates immune cells in the lymph nodes near the injection site. When the second dose is administered in the same location, these primed immune cells are ready to immediately boost the immune response.”This is a basic discovery on how the immune system is organized,” said Professor Tri Phan, Director of the Garvan Institute of Medical Research Immunology program. “Nature has developed this brilliant system, and we are just starting to understand it.”

Vaccines stimulate the progress of antibody-producing immune cells (memory B lymphocytes) and other cells,such as macrophages,which interact with them and “speak” so that they modify antibodies as a function of mutations in the virus or that they react faster.

Interestingly, a previous study from Oregon Health & Science University suggested that using different arms for each dose resulted in a higher antibody count.

Mee Ling munier, co-author of the UNSW study and researcher in vaccinology, notes that the benefit of same-arm vaccination is primarily observed after the second dose. Thus, it’s unlikely to have a significant impact on annual vaccines like the flu shot.