An urgent update about the UK covid strain, about which I'm alarmed. So excuse the wordiness of this post. Keep in mind that none of what I write below is certain. I'd say there's about a 70% chance that the new strain spreads much faster (>50%) than existing strains of covid. Here's how we know that and why it is terrible news. As always, I'm not an expert in this, please correct me if you spot errors.
1) We already knew that the strain was rising to dominance in the South and East of the UK, starting in September. It's now been found all over the UK, across Europe, in the US, South America, Middle East, Australia, Asia...basically everywhere they've had time to look. Brooks Miner has helpfully made this map showing where cases are being found: https://public.tableau.com/profile/brooks.miner#!/vizhome/MapVariants/Dashboard. So far very few cases detected outside the UK but we have almost certainly missed many, many more. In the US and several European countries, there's already good evidence of local transmission, at least on a small scale. If we're very lucky, it hasn't had time to spread much - but this is looking increasingly unlikely.
2) See my last post for what we knew a few days ago. The main new information we have is twofold. (i) Virus levels in people with the UK strain seem to be 10-100 times higher than people with other strains on average (although with huge variation between individuals). This *might* be because of biases in the data - this sudden rise in testing may mean that cases are now caught earlier, before the immune system has reduced virus levels. But the most plausible explanation is that this is a real biological difference. It would also explain why the strain is transmitted so much more - people infected with it are producing more viruses and (presumably) expelling more as well. (ii) There's also some moderately persuasive data showing that people infected with this strain recently have infected more people themselves (more precisely, the secondary attack rate was about 50% higher). Along with the rise to dominance of the strain in the UK and what little we know about the mutations, these pieces of information point towards this being a real and dangerous phenomenon. There isn't consensus about this and there are still some puzzling pieces - we don't have clear evidence of rapid rise in other European countries though the opportunity has been there. But if true the implications are disastrous and I'm very glad countries did not wait to react. They will have to do much more, and fast.
3) What does a 50% rise in transmission mean? It's very, very bad - much worse than a 50% increase in how lethal the virus is! That's because we are talking about increasing the speed of an exponential process - like compound interest for your bank account, or GDP growth rate. I'm just going to steal this excellent example from Adam Kucharski on Twitter to explain what it does. Remember that R = reproduction number, or number of people 1 infected individual will go on to infect on average (so the goal is to get R below 1, which means a decreasing epidemic):
"As an example, suppose current R=1.1, infection fatality risk is 0.8%, generation time is 6 days, and 10k people infected (plausible for many European cities recently). So we'd expect 10000 x 1.1^5 x 0.8% = 129 eventual new fatalities after a month of spread... Now suppose transmissibility increases by 50%. By above, we'd expect 10000 x (1.1 x 1.5)^5 x 0.8% = 978 eventual new fatalities after a month of spread."
So increasing the fatality rate by 50% would kill about 60 more people in a month, but increasing the transmission rate by 50% would kill 850 more. And the 1 month time horizon is arbitrary. If you look a bit longer it gets even worse, at least till the virus has infected so many people that it has limited its pool of people to infect (which is what approaching herd immunity means).
Full thread at https://twitter.com/AdamJKucha.../status/1343567425107881986
4) It took from September to December for the strain to rise to a majority or near-majority across several regions in the UK, despite lockdowns. Lockdowns reduced R below 1 for other strains - but not this new one. Measures that used to be enough to reduce R below 1 and control the pandemic are no longer sufficient (this is a complicated topic but FWIW, I don't think stay-at-home orders were or are necessary). We need to take measures that earlier would have reduced R below 0.67 for the earlier strains, because a 50% increase in 0.67 = 1 (R would have to go ever lower if the strain spreads more than 50% faster, which remains possible). This is incredibly difficult. There are only a small handful of countries in the world that have ever reduced R below 0.67 in the past year. In recent months, it looks like only Azerbaijan and possibly Cambodia, Belgium and Papua New Guinea have done it, and that's assuming we can trust the numbers. (R estimates from https://epiforecasts.io/covid/, which covers most but not all countries). Some of the harshest lockdowns in the world have not driven R this low - and we need to do this now, in the face of an exhausted populace with an angry and conspiratorial minority. I don't think we will do it.
5) If we cannot control spread (which is possible but seems unlikely to me), rich countries may just about get ahead of this by going all out on vaccinations as fast as possible (assuming the vaccines protect against it, which is still very likely). It will probably take 1-2 months before this strain rises to dominance in countries other than the UK and some countries are well-placed to take advantage of this. Canada and the UK have already taken the wise decision to not hold on to people's second doses but to vaccinate as many people as possible with the first dose right away. The UK is going further by stretching out the period between the first and second dose to vaccinate more people. This is going to be extremely controversial because this is not how the vaccines were tested and they are going on the expectation that immunity will reduce quite slowly. It's a risky but warranted measure in my opinion. It slightly increases risk to individuals being vaccinated - which is why many doctors will hate it - but will save many more people in the population (see my last post for a related discussion of ethics). The US is not taking these steps but is distributing huge numbers of vaccines. It is failing miserably in administering them so far (potentially wasting many doses), but I expect this will turn around and they will have ~60-100 million people vaccinated by March. This will make it much harder for the strain to spread, and since they will vaccinate old people first, the number of possible deaths should be much lower by April despite the new strain. The EU will take much longer to get vaccines, and there is also surprisingly high vaccine scepticism (40-60% in France unwilling to take it!). Given that there is already community spread on the continent and it was already doing a bad job controlling the previous strains, I expect the new strain to spread rapidly. I'd put a high probability on the situation across Europe getting much worse by early March because of the new strain (several assumptions here, and I really hope this is wrong). Again, targetted vaccinations could ameliorate this substantially, but Europe has a lot of old people and not many vaccines. Germany expects to begin mass vaccination only by March or April, by which time 1/3 to 1/2 of the US will probably be vaccinated. For a comparison with a more competent response, Israel has already vaccinated nearly 50% of people over 60, and about 10% of its whole population.
6) My biggest concern is developing countries that have just about been able to control spread. For example, India has had covid numbers reduce steadily since September (this merits its own post) with R at about 0.8 to 0.9 for several months. Increase that by 50% and we're quickly back in an exploding epidemic in a country that has already been hammered by covid; its economic consequences alone have undone several years of poverty reduction, which almost certainly has led and will lead to a large loss of life. And because rich countries have monopolised (to exaggerate only a little) doses from all the approved and soon-to-be-approved vaccines, a majority of the population may not be vaccinated even by end-2021, when Europe and North America are well on the road to recovery. The Chinese and Russian vaccines may help poor countries a great deal if they are effective (as seems increasingly likely) and production can be rapidly ramped up, because it seems likely that they will be shunned by developed countries. But overall, it's hard to escape the feeling that in 2021 and likely beyond, developing countries will continue to bear the brunt of bad policy in developed countries.
7) And at the risk of flogging a dead horse, I hope the last 2 points bring home just how much good we might have done by evaluating, producing and distributing vaccines faster. The vague desire to preserve confidence in the system and to not cause risk to individuals has led to the loss of countless lives already, with many, many more to come. If nothing else, 2020 should have made you more sceptical of governments and bureaucracies, even those run by well-intentioned experts.
8) We don't know yet if the UK strain is more lethal. You will see reports saying it's not different, but these are based on very limited case numbers that are being overinterpreted. We just don't know, and there's a decent chance that it actually is more lethal because of the increased virus numbers. It may be a while before we have enough data to evaluate that with any confidence.
9) What can you do? (i) Talk to people you know about vaccinations! If you have questions about them, chime in here or contact me and I'll try to help you find an answer. I would strongly recommend you get any vaccine you have access to right now, but there's a lot of very reasonable uncertainty and concern about them. If you have training in science or medicine, please talk to friends and family about this - you might be surprised at just how common worries about vaccination are. (ii) Pressure your governments to get vaccines out ASAP if you have any influence. (iii) Avoid people especially for the next week, since many will have returned from meeting family over the holidays - that might lead to a spike in cases by late January. (iv) Expect case loads to rise in Feb even if the conditions are presently improving where you are, and plan accordingly. Don't make plans for late Feb or March. (v) Otherwise, do the same things we've been talking about for months, but remember that there's now less margin for error. Don't meet people indoors, in semi-enclosed spaces or in crowded outdoor spaces. If you must be indoors, wear a mask and push hard for better ventilation. Don't mistake the surface-cleaning and hand-sanitising for actual safety, those do not achieve much and only give the appearance of safety.
1) We already knew that the strain was rising to dominance in the South and East of the UK, starting in September. It's now been found all over the UK, across Europe, in the US, South America, Middle East, Australia, Asia...basically everywhere they've had time to look. Brooks Miner has helpfully made this map showing where cases are being found: https://public.tableau.com/profile/brooks.miner#!/vizhome/MapVariants/Dashboard. So far very few cases detected outside the UK but we have almost certainly missed many, many more. In the US and several European countries, there's already good evidence of local transmission, at least on a small scale. If we're very lucky, it hasn't had time to spread much - but this is looking increasingly unlikely.
2) See my last post for what we knew a few days ago. The main new information we have is twofold. (i) Virus levels in people with the UK strain seem to be 10-100 times higher than people with other strains on average (although with huge variation between individuals). This *might* be because of biases in the data - this sudden rise in testing may mean that cases are now caught earlier, before the immune system has reduced virus levels. But the most plausible explanation is that this is a real biological difference. It would also explain why the strain is transmitted so much more - people infected with it are producing more viruses and (presumably) expelling more as well. (ii) There's also some moderately persuasive data showing that people infected with this strain recently have infected more people themselves (more precisely, the secondary attack rate was about 50% higher). Along with the rise to dominance of the strain in the UK and what little we know about the mutations, these pieces of information point towards this being a real and dangerous phenomenon. There isn't consensus about this and there are still some puzzling pieces - we don't have clear evidence of rapid rise in other European countries though the opportunity has been there. But if true the implications are disastrous and I'm very glad countries did not wait to react. They will have to do much more, and fast.
3) What does a 50% rise in transmission mean? It's very, very bad - much worse than a 50% increase in how lethal the virus is! That's because we are talking about increasing the speed of an exponential process - like compound interest for your bank account, or GDP growth rate. I'm just going to steal this excellent example from Adam Kucharski on Twitter to explain what it does. Remember that R = reproduction number, or number of people 1 infected individual will go on to infect on average (so the goal is to get R below 1, which means a decreasing epidemic):
"As an example, suppose current R=1.1, infection fatality risk is 0.8%, generation time is 6 days, and 10k people infected (plausible for many European cities recently). So we'd expect 10000 x 1.1^5 x 0.8% = 129 eventual new fatalities after a month of spread... Now suppose transmissibility increases by 50%. By above, we'd expect 10000 x (1.1 x 1.5)^5 x 0.8% = 978 eventual new fatalities after a month of spread."
So increasing the fatality rate by 50% would kill about 60 more people in a month, but increasing the transmission rate by 50% would kill 850 more. And the 1 month time horizon is arbitrary. If you look a bit longer it gets even worse, at least till the virus has infected so many people that it has limited its pool of people to infect (which is what approaching herd immunity means).
Full thread at https://twitter.com/AdamJKucha.../status/1343567425107881986
4) It took from September to December for the strain to rise to a majority or near-majority across several regions in the UK, despite lockdowns. Lockdowns reduced R below 1 for other strains - but not this new one. Measures that used to be enough to reduce R below 1 and control the pandemic are no longer sufficient (this is a complicated topic but FWIW, I don't think stay-at-home orders were or are necessary). We need to take measures that earlier would have reduced R below 0.67 for the earlier strains, because a 50% increase in 0.67 = 1 (R would have to go ever lower if the strain spreads more than 50% faster, which remains possible). This is incredibly difficult. There are only a small handful of countries in the world that have ever reduced R below 0.67 in the past year. In recent months, it looks like only Azerbaijan and possibly Cambodia, Belgium and Papua New Guinea have done it, and that's assuming we can trust the numbers. (R estimates from https://epiforecasts.io/covid/, which covers most but not all countries). Some of the harshest lockdowns in the world have not driven R this low - and we need to do this now, in the face of an exhausted populace with an angry and conspiratorial minority. I don't think we will do it.
5) If we cannot control spread (which is possible but seems unlikely to me), rich countries may just about get ahead of this by going all out on vaccinations as fast as possible (assuming the vaccines protect against it, which is still very likely). It will probably take 1-2 months before this strain rises to dominance in countries other than the UK and some countries are well-placed to take advantage of this. Canada and the UK have already taken the wise decision to not hold on to people's second doses but to vaccinate as many people as possible with the first dose right away. The UK is going further by stretching out the period between the first and second dose to vaccinate more people. This is going to be extremely controversial because this is not how the vaccines were tested and they are going on the expectation that immunity will reduce quite slowly. It's a risky but warranted measure in my opinion. It slightly increases risk to individuals being vaccinated - which is why many doctors will hate it - but will save many more people in the population (see my last post for a related discussion of ethics). The US is not taking these steps but is distributing huge numbers of vaccines. It is failing miserably in administering them so far (potentially wasting many doses), but I expect this will turn around and they will have ~60-100 million people vaccinated by March. This will make it much harder for the strain to spread, and since they will vaccinate old people first, the number of possible deaths should be much lower by April despite the new strain. The EU will take much longer to get vaccines, and there is also surprisingly high vaccine scepticism (40-60% in France unwilling to take it!). Given that there is already community spread on the continent and it was already doing a bad job controlling the previous strains, I expect the new strain to spread rapidly. I'd put a high probability on the situation across Europe getting much worse by early March because of the new strain (several assumptions here, and I really hope this is wrong). Again, targetted vaccinations could ameliorate this substantially, but Europe has a lot of old people and not many vaccines. Germany expects to begin mass vaccination only by March or April, by which time 1/3 to 1/2 of the US will probably be vaccinated. For a comparison with a more competent response, Israel has already vaccinated nearly 50% of people over 60, and about 10% of its whole population.
6) My biggest concern is developing countries that have just about been able to control spread. For example, India has had covid numbers reduce steadily since September (this merits its own post) with R at about 0.8 to 0.9 for several months. Increase that by 50% and we're quickly back in an exploding epidemic in a country that has already been hammered by covid; its economic consequences alone have undone several years of poverty reduction, which almost certainly has led and will lead to a large loss of life. And because rich countries have monopolised (to exaggerate only a little) doses from all the approved and soon-to-be-approved vaccines, a majority of the population may not be vaccinated even by end-2021, when Europe and North America are well on the road to recovery. The Chinese and Russian vaccines may help poor countries a great deal if they are effective (as seems increasingly likely) and production can be rapidly ramped up, because it seems likely that they will be shunned by developed countries. But overall, it's hard to escape the feeling that in 2021 and likely beyond, developing countries will continue to bear the brunt of bad policy in developed countries.
7) And at the risk of flogging a dead horse, I hope the last 2 points bring home just how much good we might have done by evaluating, producing and distributing vaccines faster. The vague desire to preserve confidence in the system and to not cause risk to individuals has led to the loss of countless lives already, with many, many more to come. If nothing else, 2020 should have made you more sceptical of governments and bureaucracies, even those run by well-intentioned experts.
8) We don't know yet if the UK strain is more lethal. You will see reports saying it's not different, but these are based on very limited case numbers that are being overinterpreted. We just don't know, and there's a decent chance that it actually is more lethal because of the increased virus numbers. It may be a while before we have enough data to evaluate that with any confidence.
9) What can you do? (i) Talk to people you know about vaccinations! If you have questions about them, chime in here or contact me and I'll try to help you find an answer. I would strongly recommend you get any vaccine you have access to right now, but there's a lot of very reasonable uncertainty and concern about them. If you have training in science or medicine, please talk to friends and family about this - you might be surprised at just how common worries about vaccination are. (ii) Pressure your governments to get vaccines out ASAP if you have any influence. (iii) Avoid people especially for the next week, since many will have returned from meeting family over the holidays - that might lead to a spike in cases by late January. (iv) Expect case loads to rise in Feb even if the conditions are presently improving where you are, and plan accordingly. Don't make plans for late Feb or March. (v) Otherwise, do the same things we've been talking about for months, but remember that there's now less margin for error. Don't meet people indoors, in semi-enclosed spaces or in crowded outdoor spaces. If you must be indoors, wear a mask and push hard for better ventilation. Don't mistake the surface-cleaning and hand-sanitising for actual safety, those do not achieve much and only give the appearance of safety.
