There have been a lot of questions about immunity since the start of the coronavirus pandemic.
COVID-19 is a new virus. So when it first hit there were a lot of questions about whether patients who recovered were immune and for how long.
Initial reports were not great. With studies finding antibodies fading in a few months after infection. But now scientists have been able to do more robust research and the news is good.
The study has not been peer-reviewed or published in a scientific journal, but it is the largest and longest research project so far on coronavirus immunity.
It shows that immunity could last years, maybe even decades.
It supports other recent research that shows while antibodies may fall, immune memory sticks around.
Helper T cells that recognize coronavirus after fighting it before, recruit other immune cells to make the needed antibodies.
Despite the good news, this does not mean you are 100 percent safe after recovery. There have been rare but documented cases of reinfection.
Researchers do say this could mean you will only need to be vaccinated every decade or so, unlike once a year with the flu shot.