Sydney, April 30
Receiving a vaccine booster in the same arm as the first dose triggers a faster and stronger immune response and helps the body build protection faster, according to new research.
The findings could help improve vaccine strategies and may eventually lead to vaccines that need fewer boosters, Xinhua news agency reported.
The study, which was led by the Garvan Institute of Medical Research and the Kirby Institute at the University of New South Wales (UNSW) Sydney in Australia finds that the immune system responds more quickly when both doses are given in the same arm.
That's because immune cells in nearby lymph nodes, which are the body's infection-fighting hubs, become "primed" after the first shot. When the booster arrives in the same spot, these cells spring into action and help produce stronger antibodies, the team explained in the paper, published in the journal Cell.
Researchers discovered this effect first in mice, then confirmed it in a clinical study involving 30 people who received the Pfizer Covid-19 vaccine. Those who had both doses in the same arm developed faster and more effective protection, especially against Covid-19 variants like Delta and Omicron.
"This is a fundamental discovery in how the immune system organizes itself to respond better to external threats," said Tri Phan, director of the Precision Immunology Programme at the Garvan Institute.
While both groups ended up with similar antibody levels after four weeks, the same-arm group gained protection more quickly, a potential game-changer during pandemic outbreaks.
"If you've had your Covid jabs in different arms, don't worry, our research shows that over time the difference in protection diminishes," said the study's co-senior author Mee Ling Munier from the Kirby Institute.
But during a pandemic, even a few days can make a big difference, said Munier
— IANS
Reader Comments
Interesting research! During our vaccination drive, many centers alternated arms without much thought. Maybe our health ministry should consider this for future immunization programs. Though I wonder if this applies to all vaccines or just COVID shots? 🤔
Good to know! I got both my Covishield doses in the left arm because I'm right-handed. Guess I accidentally did the right thing! 😄 But seriously, this could be valuable info for our healthcare workers administering vaccines in rural areas too.
The sample size seems quite small (only 30 people). While the findings are promising, we should wait for larger studies before changing vaccination protocols. Our ICMR should conduct similar research with Indian vaccines like Covaxin.
Fascinating how our bodies work! The lymph node explanation makes sense. I remember my grandmother used to say "always keep medicines on one side" - maybe there was some traditional wisdom behind it after all!
While this is useful research, I hope it doesn't create unnecessary panic among people who got shots in different arms. As the study says, the difference diminishes over time. Let's focus on getting vaccinated rather than worrying about which arm!
This could be particularly important for our elderly population who need quicker protection. Maybe vaccination centers should note which arm was used for first dose in the CoWIN app for booster planning. Good job by Australian researchers! ðŸ‘
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