Are there more cases among the elderly, because the generally better immune system of younger people is more likely to prevent it getting established ?
Or are more cases just being reported for the elderly because the young may just think they have a cold, but the elderly are much harder hit by symptoms ?
Don't know.
The Italians have said that it was initially the elderly who were presenting as cases and more recently its been younger cases that have appeared.
I think I'd probably say that older people presented earlier in part because they had more serious cases, but I also think there's something about it taking longer for younger people to catch the disease too.
Perhaps that's to do with level of exposure meaning for example that elderly people are infected on first exposure (100% chance of infection if exposed) to the disease but a younger person might be exposed once and not get it until say their third exposure (33% chance of infection if exposed). As the disease becomes more common, you are more likely to be exposed multiple times.
I am very much speculating, but that could be one explanation.
That would mean an absence of cases in metropolitan areas could be to do with younger people needing more exposure - if that's the case then it makes cities a ticking time bomb in a different way to counties like Devon as they will explode in numbers from apparently no where....