A recent study shows Oxford/ AstraZeneca’s vaccine gives powerful protection and generates robust long-term immune system responses that may last a lifetime! As well as generating virus-busting antibodies, the vaccine also creates “training camps” in the body for for search-and-destroy T-cells (CD8+ T-cells) which can kill even new variants!
What does this mean? It means your immune system can continue making these vital cells long after antibodies have waned- and possibly for the rest of your life! Researchers showed adenovirus vectors can target specific cells- known as stromal cells in tissues such as the lung – generating antigen ‘depots’ in these long-lived cells. These stromal cells were originally thought just to provide an inert scaffold for the tissues, but it appears that they are very dynamic cells with a major role in immune control. The long lived nature of the cells means that the antigen can be ‘shown’ to the immune system many times, effectively boosting the response, a critical element of generation of protective T-cells. They were also able to investigate other mechanisms which may explain the particular efficacy of adenovirus vectors, including the key chemical messenger involved in signalling to T-cells. This is a factor called IL-33 – an “alarmin” that is released when the stromal cells receive signals of distress. IL-33 acts to strongly boost to the metabolism of T-cells, resulting in effectively more energetic cells and a highly protective immune response.
“Adenoviruses have co-evolved with humans over a very long time, and learned a lot about the human immune system in the process. Viruses are always the best teachers, and here they have taught us an important lesson about how best to boost killer T-cell responses. The T-cells that come from these cellular training camps appear to have a very high level of “fitness.”