Daijiworld Media Network - Sydney

Sydney, Apr 30: New research led by the Garvan Institute of Medical Research and the Kirby Institute at the University of New South Wales (UNSW) Sydney, Australia, suggests that receiving a vaccine booster in the same arm as the first dose leads to a faster and stronger immune response. This finding could revolutionize vaccine strategies and potentially reduce the need for multiple booster shots in the future.

The study, published in the journal Cell, reveals that when both doses are administered in the same arm, the immune system responds more rapidly and effectively. Immune cells in nearby lymph nodes, which act as the body's infection-fighting hubs, are "primed" by the initial dose. When the booster is delivered to the same area, these cells spring into action, leading to the production of stronger antibodies.

The researchers initially observed this phenomenon in mice and later confirmed it in a clinical trial involving 30 individuals who received the Pfizer COVID-19 vaccine. The results showed that participants who received both doses in the same arm developed faster and more robust protection, particularly against variants like Delta and Omicron.

Tri Phan, director of the Precision Immunology Programme at the Garvan Institute, emphasized the significance of this discovery. "This is a fundamental finding in how the immune system organizes itself to respond better to external threats," Phan said.

While the antibody levels after four weeks were similar in both groups, those who received both doses in the same arm gained protection more quickly. This accelerated immune response could prove crucial in pandemic situations, where every day counts.

Mee Ling Munier, co-senior author of the study from the Kirby Institute, reassured individuals who received their COVID-19 shots in different arms, noting that over time, the difference in protection would lessen. However, Munier highlighted that during a pandemic, even a few days of faster immunity could make a significant difference in controlling outbreaks.

This breakthrough research could have long-term implications for vaccine development, potentially reducing the need for frequent booster shots and optimizing vaccine strategies globally.