Patrick Vallance @uksciencechief and Chris Whitty @CMO_England are speaking at a #covid19 briefing for science journalists. Live tweets coming up.
CW: As science advisers to the government, you are dealing with uncertainty. You have large numbers of scientists from different disciplines. There are lots of questions we don’t know the answer to.
When we started out in Jan/Feb there were 2 scenarios that were realistic. 1. A major outbreak in China with some spillover elsewhere. It could be controlled at source. The virus going away was a realistic outcome.
The other plausible outcome was that this would turn into a widespread epidemic/pandemic. Our original strategy tried to cover off both scenarios.
Now it seems so improbable that we could have made this go away that producing advice to cover it now seems a mistake.
Q: Should there be more emphasis on the provisional nature of the modelling? PV: We’re very clear about that – it’s a prediction with wide confidence intervals. The politicians understand that.
CW: We are now quite confident about mortality rates. We still don’t know what proportion of people catch this and don’t show symptoms. But the models are improving as data improves.
CW: The track of the epidemic has followed the path we thought it would follow since we made the decision that it would become a pandemic. The question is what to do at what stage.
The interventions have significant health and social downsides. If you do them too early you get all the negatives but very little effect on the epidemic. You have to judge when they are worthwhile.
How long will this go on for? PV: The priority is to reduce the peak as much as we can. Once we’re there we can think about relaxing measures. Testing is important to see how many people have had it. We dealing with a brand new virus. Putting timelines on things is not possible.
CW: As time has gone by we have become more confident about the death rate. It varies significantly depending on age. In the UK, it looks higher than other countries because our testing system is based on people who have reached hospital.
CW: Our aim is to delay the peak and pull the peak down, so it is better matched to what the health service can manage. People can die because of infection, or they can die because the health service is overwhelmed.
Another advantage is if you let an epidemic run its course, you get “overshoot”. By lowering the peak, you reduce the overall number of people who get the infection.
PV: Many groups are working on serological (blood) tests. That would tell us who has had it and now has antibodies, therefore won’t catch it again. Scaling this up will take time.
PV: There are 8000 or so deaths from flu in an average season. If we can contain this to a level that is comparable to that, that would be a remarkable outcome, given we don’t have vaccines.
CW: The mitigation strategy has 2 components: pull the peak down to reduce demand. The second part is to increase supply. The NHS is working hard to do that.
Will the virus mutate to become more virulent? CW: We can't predict that, but viruses tend to adapt to become less virulent. Mutations help us to track the virus spread by building family trees.
Q: Should containment and isolation be used more? CW: If you have a global pandemic that’s everywhere in the world, the idea that you can contain it in the UK isn’t plausible.
Q: Lots of young people don’t seem to get that this is more serious than flu. Is your message landing? CW: The majority of those who die are in the later part of their lives, or have pre-existing conditions. There are also some young people who end up in intensive care.
PV: Unless everybody follows the measures introduced by the government, it won’t work. Young people can’t ignore it. Mixing in pubs is an important part of spread and it needs to stop among young and older people.
The briefing has now finished. You can catch up with all our latest #covid19 coverage and analysis here. newscientist.com/article/223747…
