Two paths to controlling COVID with vaccinations

 

As vaccination is rolled out across advanced economies, the main danger has become mutations of the virus, or variants. We all know about the B.1.1.7 variant that emerged in the UK in September and helped generate the rapid rise in cases in December. We also know about the ‘South African’ variant (B.1.351), which appears to reduce the effectiveness of all vaccines to some degree. But these are just two of the better known variants, which seem to be emerging all the time (see also here).

COVID variants are the reason that so many countries have now severely restricted travel (‘almost closed borders’) into their countries in recent weeks. One of these variants could severely reduce the effectiveness of a country’s vaccination programme. It is likely that scientists would be able to change their vaccines to deal with these variants, but that will still mean at least another year before everyone is re-vaccinated and therefore means another year of lockdowns. We also do not know whether scientists could ever win a race between vaccine development and the ability of the virus to mutate.

Virus variants arise when there is a large amount of the virus about. One of the many failings of Western countries during this pandemic is to believe that you could safely vaccinate in an environment where domestic cases were high. That is exactly the environment that encourages mutations that are better at avoiding vaccines. If Western countries had followed an elimination strategy after the initial outbreaks in Spring last year, it would have been possible to keep borders open between these countries and the chances of producing a variant that can bypass vaccines within these countries would have been eliminated. In addition we would have had a small fraction of the deaths we have seen, with much less disruption to the economy.

Western countries now face a choice of how they handle COVID as vaccines are rolled out. Although no doubt reality will be far more complex than this, I think we can illustrate two types of outcomes available to them by thinking about two possible paths. I will call these two alternative paths ‘elimination’ and ‘living with COVID’. As with any attempt to look into the future, it assumes an existing technology that could change, and it involves some assessments that may prove wide of the mark (or maybe just wrong).

Elimination

This path tries to use a combination of almost closed borders, vaccination and other measures to enforce social distancing (including lockdowns) to get cases down to very low levels. At these very low levels, measures to enforce social distancing can be relaxed and an efficient test, trace and isolate (TTI) programme can keep R<1. During the summer, zero-COVID is achieved. The advantages of elimination are (see also here)

1. Once elimination is achieved, there is no chance that COVID variants that can bypass vaccines will emerge at home. While elimination is being achieved those chances are greatly reduced. This gives scientists a chance to develop new vaccines that can deal with known overseas variants while keeping everyone safe and COVID-free.
   
   

2. Countries that have achieved elimination can very easily open their borders to other countries that have done the same. Obviously this advantage is not that great if no other Western countries eliminate the virus.
   
   

3. Once elimination is achieved, the domestic economy can fully recover, there will be no more deaths from COVID, and there will be no more new cases of long COVID.

There is an important caveat to these three advantages. No ‘almost closed border’ is going to be foolproof, as both Australia and New Zealand have seen. When failure occurs, if TTI cannot eliminate the new cases, a short sharp lockdown is required to ensure the country returns to zero-COVID.

Living with COVID

This alternative arises when governments do not make any attempt at elimination, and two other outcomes prevail

1. Because of widespread vaccination together with TTI, countries can ensure R is very slightly below one in the summer months (If R is a lot less than one, elimination may occur naturally.)
   
   

2. However because COVID cases are still around by the end of summer, as winter approaches R increases to be above one, and cases increase. However because of vaccination cases never increase by enough to threaten health services, and once spring appears (or possibly before that) cases start to decrease again. (If cases rise in winter sufficiently to overwhelm the NHS, a further lockdown will be required.)
   
   

In this situation COVID becomes more like flu (it clearly isn’t like flu without vaccination), causing many deaths in winter but largely disappearing in summer. We learn to live with COVID.

Opening up borders now becomes a more messy affair. Countries would have to take informed guesses about whether other countries COVID cases were ‘safe’ (meaning they contained no dangerous variants) or not. However if most countries do not eliminate COVID, it will be easier to open borders to many countries than under elimination, once those countries have a similar number of cases that don’t include dangerous variants

There are two risks under this strategy. The positive risk is that vaccination turns out to be able to keep R<1 for most of the time, so COVID gradually dies out. This may happen because people feel more confident about being vaccinated as time goes on, and vaccines get better. Under this outcome, we don’t have to live with COVID for very long.

The negative risk is that during winter months when cases are high a mutation may develop that could bypass existing vaccines (partially or completely). This would be a very dangerous outcome, because it is likely to be some time before this variant is detected, by which time its numbers have multiplied substantially. (An advantage of the elimination strategy is that all outbreaks are treated as if they were dangerous, and are obviously much easier to see.) It is not clear to me how such a situation could be controlled without at least a year of lockdowns while new vaccines are developed and/or rolled out. The same danger arises from a failure in the ‘almost closed border’ that lets in a case with a COVID variant that can bypass vaccines.

Compared to the elimination strategy, there are two obvious advantages in living with COVID. The first is that lockdown can be relaxed or ended earlier. The second is that the country becomes less vulnerable to failures in its ‘almost closed borders’. The certain disadvantage compared to elimination is more deaths, and there is also the risk of allowing the development of variants that can bypass existing vaccines.

East versus West

At present the elimination strategy is being adopted by a group of countries which is small in number but does include China as well as Australia, New Zealand and Taiwan. There is no indication at the moment that any other countries are likely to join this group. It is also unclear whether these countries will continue with elimination once vaccination is widespread. They may be doing similar analysis to this (although no doubt better) to help them decide.

One prudent policy for the existing elimination countries is to wait and see how ‘living with the virus’ works out. If Western countries do learn to live with that strategy, the negative risks I point out above do not in practice occur, and they succeed in opening borders to each other at least, then there will be a strong incentive for the elimination countries to abandon that strategy. Equally, however, if it looks like Western countries are constantly playing catch-up with new domestically generated virus variants that bypass existing vaccines we may begin to see some Western countries begin to adopt elimination.

The UK government’s strategy for ending lockdown

Of the four criteria the UK government is going to use in deciding how quickly to ease its lockdown, steadily reducing cases is not among them. Instead we have “Infection rates do not risk a surge in hospital admissions” which is a much weaker criteria. It is actually exactly the criteria you would have under the ‘living with COVID’ strategy. It is therefore clear if unsurprising that the UK government has no intention of switching to an elimination strategy.

Much has been made of the government’s new step by step, data driven patient approach. What is less often said is that such an approach is essential to avoiding another resurgence in cases when most people have not yet been vaccinated. (Perhaps Tory MPs wanting to open everything quickly are only there to make the government look good?) Opening schools all at once in March is a risk. While it is good that secondary school children will be required to wear masks at all times, in France children aged six and over are told to do this. There is probably a lot more that could be done for schools in terms of ventilation, bubble sizes and so on. We also need to prepare for the possibility that schools going back may raise R to almost one, which would effectively invalidate the government's approach.

What is also not widely appreciated is that SAGE forecasts, like those released yesterday, are going to play a critical role in deciding how quickly lockdown is relaxed. Only in this context does the need to ensure “Infection rates do not risk a surge in hospital admissions” make sense. What SAGE needs to forecast is what level of cases in the summer, with lockdown at an end, is sufficient to ensure that the increase in cases over autumn and winter does not overwhelm the NHS. It is a very difficult forecast to make because we have no experience of what happens when most people are vaccinated, and if the government is wise it will base its calculations (on when to ease lockdown) on a worse case scenario. Unfortunately if it did that it would be acting out of character.

You also have to ask whether, if you intend to follow data rather than dates, it is wise to then announce a complete set of dates attached to a detailed list of the restrictions that will be lifted all the way to the end of lockdown? This gives a mixed message at the very least. In reality, given that we are far from clear how effective each element of the lockdown is, there may be a danger that the whole timetable is built on sand. But in political terms, this timetable is going to have a strong influence on expectations (where caveats are forgotten or just ignored by print media). The net result may be that disappointing those expectations will be a large political cost that politicians will not want to incur. A timetable this precise may have the effect of taking decisions away from the scientists when the data turns out to be worse than expected.  

Why vaccines alone are not enough, how the UK government could mess things up again and which European country will eliminate COVID first?

 

Why has the UK government decided to apply serious travel restrictions to incomers because of COVID now, almost a year after the pandemic began? What took them so long, and what has changed? The obvious answer to the second question is vaccination and mutation.

We don’t know how much the vaccines so far approved will stop people passing on the infection to others, but what evidence we have suggests there will be at least some dampening effect. Israel is likely to provide the first firm evidence on this. That will reduce R, the number of people one infected person passes the illness on to. What vaccines will certainly do is substantially reduce the chance of people getting ill from COVID.

The danger is that, as vaccines are rolled out, the virus develops the ability to bypass them through mutation, so vaccines either don’t work at all against this new variant or work less well. This doesn’t seem to have happened to a large extent yet, and it isn’t inevitable, but it has happened to a small extent and it would be unwise to assume it will not happen. The chances are that variants are likely to emerge in other countries first, so it makes sense to try and stop that variant entering into the UK for at least as long as possible.

While this provides an excellent justification for creating travel restrictions today, it doesn’t explain why effective general restrictions were not imposed before. (There have been requirements to self-isolate, but these seem largely voluntary.) A cynic might say that the underlying UK strategy is and always has been herd immunity, but I think that only applied at the beginning of the pandemic. After then, with UK cases more often than not higher than elsewhere, the incentive for effective and generalised border controls was not enough to motivate this government.

While the chances are that any variants that can bypass vaccines will emerge abroad, it is possible they will emerge in the UK because we are vaccinated in an environment of widespread infection. The big danger left is that Johnson will once again relax lockdown restrictions too soon, before enough people have been vaccinated. The quicker we reduce case numbers in the UK, the less chance there is that a vaccine-resistant mutation develops in the UK. In addition the more cases there are, the easier it is for an overseas variant to multiply. No restrictions on people entering can be 100% safe, as New Zealand recently found, and a complete ban on people entering is not feasible because of returning nationals. Johnson should know this because his failure to get case numbers really low over the summer allowed the UK variant to develop and multiply.

It makes sense to reduce UK cases as quickly as possible to very low numbers, to reduce the chances of mutation and increase the chances of isolating any variant that comes in from abroad. Whether you call it zero-COVID or elimination or whatever, that strategy has always been the one that minimizes deaths and gets the UK back to normal as quickly as possible. Vaccines don’t change that reality, they just make it easier to implement. One argument put forward against an eradication strategy has been the costs of quarantine in hotels, but now the UK government is doing quarantine that argument falls away.

Just as the UK is now imposing quarantine for incoming travellers, or requiring recent tests, the same is likely to happen in other countries for similar reasons as their vaccine programmes are rolled out. For a period of time we will have many Western countries where there is much reduced inward human travel. This is an outcome that I imagined happening many months ago once the scale of the pandemic became clear, and should have happened if best practice had been followed.

Once such a situation comes about, it creates two sets of very positive incentives for countries imposing quarantine. First, each country has a strong incentive to eliminate the virus, so that they can free travel up with other countries that have done the same. We will get travel bubbles being formed. Those bubbles will be fragile, as they have been for Australia and New Zealand, but they represent the beginnings of international cooperation to eliminate the virus.

The second incentive for those countries that do eliminate COVID is to get other countries to do the same, so free travel between countries becomes possible again. But even with quarantine, risk can only be completely eliminated when all countries have eliminated the virus. So the second incentive is to get the vaccine to poorer parts of the world as quickly as possible, with the help of international cooperation.

That is the strategy that the UK should now follow. However the UK is a country that has more than a 100,000 dead from the virus, with currently one of the highest death rates in the world. This reflects in part the fact that we have a weak Prime Minister, who is very indecisive, puts off decisions, wants to please and is easily swayed by pressure from others. We already have a large number of Tory MPs and business people who are clamouring to end the lockdown whatever dangers that brings.

The problem is that Johnson does not only listen to scientific advice, which is to avoid any relaxation for some time. He also listens to his MPs, some of whom have very strange but strongly held views on lockdowns. He has already said that he hopes to reduce some restrictions at the end of February, despite also saying that closing schools will be the first restriction to end and it probably will not happen until Easter. Of all the restrictions in the current lockdown there is a strong case for getting schools back first, but any relaxation of other elements of lockdown before then makes that less likely or more dangerous. Time and time again Johnson has gone for short term popularity with terrible long term costs, using as an excuse a trade-off between health and the economy that does not exist beyond the very short term.

Another indicator that Johnson may mess things up is how he has oversold vaccines. They have been presented as the solution to the pandemic, rather than as a key tool among many in ending the pandemic. With new infectious variants already circulating, we cannot be sure that the vaccination of everyone who is willing to be vaccinated will be enough to achieve herd immunity (see also here). But the main reason why vaccination is not enough on its own is the generation of variants. As this excellent discussion from Anjana Ahuja suggests, Taiwan, China, Australia and New Zealand are the examples to follow, and vaccination will make it much easier to follow that strategy.

It would be nice to be optimistic that some other Western countries will follow this advice. Unfortunately, while most European governments are not as foolish as ours, very few have shown much wisdom either. Read this from Le Monde on how Macron is also putting off the inevitable as cases climb. To quote, Macron “does not want to let this measure be imposed as long as the figures do not show the urgent need for it. With around 20,000 new cases per day, France can still avoid it, he believes.” You only need to look at the data to see how unlikely he is to be right.

It is an interesting question why no Western government has learnt the lessons from the East. Why do none have a leader who is prepared to go with the science? Instead we have politicians who balance what the experts say with pressure from small businesses and others in various sectors to do the opposite. Everyone wants financial support and Ministers of Finance worry about the cost. Few with any power seem to realise that the strategy that minimises costs, disruption to business and saves the most lives is locking down hard and fast, and trying to minimise cases. The media reflects the myopia of actors rather than leading. (How many discussions on how Australia has handled the pandemic have you seen in the UK broadcast media, and has it been greater than discussions of Sweden?)

The common idea as to why Australia and New Zealand have followed an eradication strategy from the start is that it is easy because they are islands with less international travel than European countries. That is not quite right for Australia. COVID policy is determined at the state level, and the states have imposed land border restrictions between each other when outbreaks have occurred. We can only hope that once European countries start imposing international travel quarantines as their vaccine programmes are rolled out, and now they have a better understanding about how not to handle the virus, some at least will follow Australia and adopt eradication as a goal.

I think it is likely that once a few European countries do this, most will follow as the advantages of an eradication policy become clear. As Norway already has a variety of border controls including hotel quarantine in place, and a low number of cases, my guess is that Norway may be among the first European countries to adopt elimination of COVID as a strategy. Finland, which also has strict entry requirements and a relatively low number of cases, is another possibility. With a head start in terms of vaccine supply it could be the UK, but with a Prime Minister who says he wants to wait before learning from past mistakes I somehow think it won't be. 

The political economy and psychology of COVID rebounds

You can call it a second wave, or a resurgence of the first wave. But whatever you call it we are seeing in some European countries a steady (and occasionally rapid) increase in new cases after a longer period when new case numbers have been coming down or been stable.

A good reason to not call this a second wave is that the first wave never went away. Changing social behaviour, aided by government support and a lockdown, reduced new case numbers rapidly. However governments relaxed the lockdown before new cases fell to almost zero, and so domestic transmission continued at a low level. But why have the number of new cases started increasing in the last few weeks in many countries, after a period of apparent stability?

The simplest answer to this question is why shouldn’t they. The natural development of the virus is to create an explosive increase in cases. The first wave didn’t come near to creating herd immunity, so if people started to behave as they did before the virus emerged a second explosion is the inevitable result. What governments and those advising them must have hoped is that

1. social behaviour had been sufficiently scarred by the pandemic that people didn’t relapse into pre-virus behaviour, and instead that they continued to social distance, wash their hands etc

2. changing social behavior was sufficient on its own to keep R at or below one, even though the economy returned to normal, and most social restrictions had lapsed.

3. the country’s track, test and isolate (TTI) technology was good enough to deal with any local outbreaks.

Even if (b) and (c) are correct (and there is no certainty they will be), there is the danger that (a) is a function of the length of time since the initial pandemic. This will be true particularly for an age group where the virus is much less of a personal threat. It is therefore quite possible that the economy remains depressed because a large group of people worry about resuming their previous levels of social consumption, and at the same time another group of people are happy to forget about the pandemic altogether.

Another factor that may account for the recent pick up in new cases is the increased social mixing that generally comes from taking holidays. Someone who has an asymptomatic case of COVID-19 could possibly infect not just their usual social circle, but also all the people they meet on holiday. Such cases, because they transcend local areas, may be more difficult for TTI to deal with.

Why were governments so keen to end the lockdown? The political economy here is pretty obvious. Governments are under pressure from business, together with individuals.who fall through or are substantially disadvantaged by the government’s support apparatus. Because social consumption is such a large part of the economy, this pressure from social consumption sectors can be intense. For the holiday industry, almost a whole year’s business may be lost over a few summer months.

In addition governments start worrying about the cost of the support they are giving. Just the hint that the current level of support may be reduced is also enough to get individuals and businesses putting pressure on governments to relax the lockdown as soon as possible. National Treasuries may add to that pressure. Finally there is the ideology of neoliberalism, which can elevate the economy to become an entity that is more important than the people within it. That influence is very clear in the UK. (Whether the UK is on the point of joining other countries suffering a COVID rebound is difficult to tell, but in some parts it probably is.)

At some point the rise in cases in some countries may force them to reimpose elements of lockdown, particularly when schools reopen. There is a danger of a cycle of periodic lockdowns as cases rise and then fall, at least until a vaccine is available. One possible alternative is to make elimination of COVID-19, rather than just its suppression, the goal of each national government. Few governments have made elimination of COVID-19 their goal, with three exceptions being New Zealand, Scotland and Northern Ireland.

Why might elimination be a better strategy? Individual psychology is shaped by social (in this case government) goals. Most governments have focused on changes (the first derivative), then people and so typically the media has done the same. If cases are rising you throw everything you have at the problem, if cases are falling you can steadily relax any lockdown, but if cases are steady (and governments tolerate that) COVID drops down the news lineup. So (a) above is more likely to fail if governments focus on changes rather than elimination.

If instead the focus becomes eliminating any new cases then initial lockdown might be a little longer, but you could achieve some positive results. First, those that are naturally cautious know that it is safe to resume social consumption, and so the economy recovers more completely, although with bigger short term costs. Second, you would save more lives. Third, and this is much more speculative, if new cases start to emerge that becomes headline news and it receives the full attention of government and TTI resources (see very recent developments in New Zealand). However New Zealand’s success with this strategy owes a lot to enforced quarantine for anyone travelling from overseas, which would be more difficult for most other countries.

I do not know whether an elimination strategy would be more successful at avoiding the kinds or rebounds in cases we are seeing in many European countries, but what is very surprising is that there seems to be little public debate on this question outside Australia. There should be a lot more debate in the UK beyond the pages of the Lancet, given the different strategies pursued by the different nations within it. With previous administrations we would expect some kind of strategy document from the UK government on something so important.

Still knee deep in boxes, so next post will be in a few weeks time.