DUBLIN — The interplay of age and vulnerability to illness has been under unprecedented spotlight due to the coronavirus pandemic, which has killed mostly older people affected by pre-existing conditions or ‘co-morbidities.’ with huge death tolls in nursing homes in many countries. But while the conventional wisdom – that people are more likely to get sick as they get older – still holds, according to the University of Oxford, their health in general, for good or bad, is less likely to be affected by genes as Father Time catches up.