Professor Philip Nolan:

It is about vaccination. It is also about detecting as many potentially importable cases as possible before you potentially import them. Missing a percentage of imported cases becomes critically important if, within that percentage, you are introducing new variants. The Deputy put his finger on the fundamental reason we are concerned in the safe reopening of travel to detect every possible case, and not only a percentage of cases, that might be coming into the country.

To answer the Deputy's second question about modelling, how quickly a more transmissible variant becomes dominant depends upon its transmission advantage, and we are not entirely sure what it is yet.

However, in the context of us having 200 to 300 new cases per day, it also depends, sadly, on how many cases we are likely to import. It depends on the number of imported new variants plus the rate at which it transmits within the population. Frankly, one can get a wide range of answers when one plugs that into different models. Models are not entirely useful in this context, because the assumptions are so broad. However, they point us to one thing, which is the vital role of surveillance at the point of entry and rapid public health intervention at the point of outbreak. These are the two things we know are critically important.