Older People Are the Last to Be Infected
Whether older people are actually infected with a delay, or whether the effect is only caused by a delay in testing/detection/reporting, cannot be determined from these figures at first.
Especially in the case of children with rather mild symptoms, there may well be a delay until the infection is detected. The situation is different in the age group 80+: there are proportionally much more severe courses of the disease than in the other age groups. Accordingly, the infections are more conspicuous there. There is also no evidence that the incubation period in this age group is longer than in the other age groups. This suggests that older people do indeed become infected with a delay.
The following considerations support this: The age groups with the most contacts and the greatest mobility are the age groups 15-34 and 35-59. It is therefore plausible to assume that these are the age groups that primarily drive the infection process and are thus among the earliest in terms of time. Now, a great many people in the age group do not have daily intensive contact with these younger age groups – not all relatives visit their (grand) parents daily and in old people's and nursing homes attention was paid very early on to the protection of the residents, which very probably delayed rapid transmission. In addition, people in the 80+ age group have relatively few social contacts on average, so it is plausible that they are the last to be affected by the infection.
This time delay must be kept in mind when making decisions around the measures to be taken.
If the incidence of infection in younger people reacts more quickly to measures, then the effectiveness of measures as a whole on individual age groups cannot be assessed by comparing incidence values over a common period of time. Finally, it may be that the effectiveness in the age group 80+ only becomes apparent a few days later than in the younger age groups. If measures are aimed at preventing the health care system from reaching its capacity limits, this delay must also be taken into account. The oldest people in our society have the highest probability of needing intensive medical care in the event of an infection. Therefore, one should think about taking measures even earlier.