we actually predicted on the 18th of december, our own modelling we put out, we thought that one in ten nhs staff would be off sick by this time because we could see the trajectory of infection rates rising. remember that people who work in nhs are part of the general population and in london, one in ten people are infected and that will reflect in those that work in public services such as the health service. the other problem we have is that front—line staff aren't able to stay at home. they are much more in contact with people and if you're a doctor or a nurse or a health care worker, you are going to be in contact closeby patients who are carrying the infection. the other problem is we are not being provided in most settings with the higher—grade masks that filtrate against airborne spread so there is also the chance we can get infected at work.