Dr. David Nabarro:

I think there will be seasonality with this because I am absolutely certain that people will get more sick in colder weather, but we want to be clear that this is not like flu. It looks as though the virus is stable and capable of being transmitted in hot weather as well as in cold weather, and it is a threat, therefore, in the warm seasons. It is a coronavirus and not flu. Part of the issue has been to help people to start thinking in terms of a different kind of mindset compared with a flu pandemic. "Continuous threat" is the language I keep using.

Face coverings really are necessary because people may well be able to transmit the virus before they develop symptoms of the disease. They may not know they are sick and, therefore, they may not know to self-isolate. The use of face coverings is important in situations where individuals are likely to be exposed to a lot of illness. This is drivers on public transport, cleaners in situations where, for example, they are dealing deal with communal facilities such as toilets, security guards, and till workers in supermarkets. In all these situations, the folk there are exposed to a lot so they should be dealing with people using face protection just in case the individual they are dealing with has actually got the virus. Spain seems to be developing a good policy on this, and I am impressed that there has been quite a high uptake. Of course, all the countries in east Asia are familiar with this after SARS in 2003. There are going to be questions about the extent to which you can rely on voluntary compliance or whether you need to make it mandatory. The Deputy did not ask me about that, but I think we need to try to push from saying people should do to people really must do, not just for their own sake but for the sake of the people who look after them. More and more I am getting worried about those who provide services being exposed to the virus by those who do not quite realise how risky they are.

I want to be absolutely certain that any vaccines available for Covid are fully tested through the full regime of the different clinical trials that are necessary for vaccines to make sure they are 100% safe. Of course, if there are individuals with side effects, it will be up to governments to decide what degree of side effects they are prepared to tolerate. We have got quite a widespread anti-vaccine movement going on in the world at the moment which means that measles, a disease for which we have a really good vaccine, is suddenly returning as a public health threat. So the safety part is super-important. Second, it is going to be necessary to demonstrate to the public that the vaccines really work. There are concerns that coronavirus will be difficult to develop an effective vaccine against. I am saying 18 months - going through all the clinical trials and get through the necessary approval stage - and possibly a year or even two years before everybody in the world can be vaccinated.

I want to ensure everyone gets a vaccine, not only those in countries that are able to pay for it. Therefore, it may be between two and a half years to three years or even three and a half years before everyone who needs it has access to an effective vaccine.