The Oxford-AstraZeneca jab gives powerful protection that may last a whole lifetime, a new study has found.Apart from generating virus-busting antibodies, the vaccine also creates "training camps" in the body for search-and-destroy T-cells which can kill even the new variants, The Sun, UK, reported.It means the body can continue making these vital cells long after the antibodies have waned, as possibly for the rest of your life, it said.Scientists from Oxford, the UK, and Switzerland, writing in the journal 'Nature', said that T-cell protection is a "key feature" of adenovirus vaccines like the Oxford and J&J jabs.As per the report, researcher Burkhard Ludewig from Cantonal Hospital in Switzerland said: "The T-cells that come from these cellular training camps appear to have a very high level of 'fitness'."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."Hopefully we can put this to good use in designing new vaccines targeting other diseases like TB, HIV, hepatitis C and cancer."The researchers found that adenoviruses are able to get into long-lived tissue cells, known as fibroblastic reticular cells, which act as "training grounds" for T-cells.Previous studies have shown that the Oxford jab is more effective in generating T-cells than mRNA vaccines like Pfizer and Moderna.T-cell levels are difficult to measure, but the new study gives hope that they may last a lifetime, the report said.Paul Klenerman from the Nuffield Department of Medicine at Oxford said: "Millions of people have received adenovirus vaccines around the world. The ultimate goal with these vaccines is the induction of long-term immune system protection using both antibodies and T-cells."This research helps us to understand more on the process of vaccination, and why the effects on killer T-cells are so prolonged."