[mynegation]

Disclaimer: not an immunologist, no formal post secondary biological education, my thoughts on this are likely worthless.

I had the same question when it all started: how exposure to other coronaviruses affects the response to SARS-Cov-2, and what does it mean for people with different history of exposures.

One hypothesis was that older people have a higher probability of dying because their immune system does not produce antibodies fast enough to keep up with the virus. The other one was the complete opposite: that due to the long history of exposures to other coronaviruses they have too much of a response and cytokine storm as a result but that does not seem to be the case.