The site in which to administer vaccines booster makes the difference: the reason, just discovered, will help design more effective vaccination campaigns.
The date of the last vaccination is not the only aspect to remember, when you present yourself for a booster. Even the arm presented at the first vaccine counts. Now an Australian study has clarified why to receive the dose of recall of the vaccines in the same arm where you received the first time produced A faster immune response.
The discovery, published in the scientific journal Cellcan be used to raise the effectiveness of the next vaccination campaigns, especially in the case of new pandemics.
Ready to intervene. The scientists of the Garvan Institute of Medical Research and the Kirby Institute of the University of New South Wales in Sydney have discovered that vaccines activate macrophagesimmune cells that usually play the role of “brushes” of the human body, within the lymph nodes closest to the vaccination site. These pre-alert cells then direct the positioning of the lymphocytes Bin charge of producing antibodies, so that they activate more quickly at the time of the booster. The discovery, initially emerged in studies on mice, was then confirmed on man.
Prepare the defenses. The lymph nodes are the seat of the immune response to vaccines, where antibodies production takes place. For this reason, it is completely normal that these small glands located along the lymphatic vessels can enlarge, a few days after a vaccination. When the vaccines introduce the harmless version of a pathogen (the antigen) into the human body or the instructions to produce it, the lymph nodes filter it and act as a “training camps” in which to organize the immune defenses against that virus.
The other role of macrophages. Once searches have shown that Memory B cells, capable of remembering a specific antigen and producing tailor -made antibodies in its presence, gather in the lymph node closest to the vaccine injection site.
Now Australian scientists have discovered that when the booster is administered in the same point as the first vaccine, the pre-alerted macrophages in the first vaccination efficiently capture the antigen and activate the memory B cells so that quickly produce antibodies high quality. They are like the orchestra directors of an effective vaccination response.
Better in the same arm. The discovery was confirmed in a clinical study on 30 volunteers who were to receive The Booster of the anti-Covid vaccine in MRNA of Pfizer-Biontech. Twenty of them received the dose of recall in the same arm as the first and 10 in the opposite arm. Volunteers of the first group produced neutralizing antibodies against Sars-Cov-2 Much fasterwithin the first week after the dose-Booster.
And their antibodies are also more effective results against the Delta and Moraron variants.
Weeks that count. Within four weeks from the Booster, the volunteers of both groups presented equivalent doses of antibodiesa protection that in both cases then attenuated over time. But a faster answer could be particularly important when playing against time, like In case of pandemic.
At the level of the population, those more weeks of optimal coverage could mean a remarkable reduction of contagions. Therefore, the strategy of vaccinating everyone in the same arm of the first time could contribute to reaching the immunity of flock faster.
In addition, understanding how to interact macrophages and memory B cells will contribute to designing the next generation of vaccines, increasing its effectiveness immediately, and reducing the need for recall doses.
