Dr. Colm Henry:

Looking at the proxy for this which is how long immunity lasts, we know that antibodies, particularly that spike protein, the bit that clasps the virus onto surfaces, can sustain for six months or so. The neutralising antibody, which is the really effective antibody against the virus, seems to wane so much after a few months. This may inform how we vaccinate people when, and if, this population-effective vaccine comes out.

It is too early to say. There is certainly antibody production, which seems to be quite sensitive. As for how long that lasts, what immunity that gives an individual and what protection it gives in respect of somebody not getting reinfected, it is too early to say, except, as I said to the Senator, that there have been reports in the medical literature on individual case histories that state a small number.