What is the red list for?

2 Sept

Time to reassess the purpose of the UK’s red list

Countries which are on the UK’s “red list” face some of the most draconian travel restrictions imposed anywhere in the world. UK citizens are told that “you should not travel to red list countries”. If you have been in a red list country in the last 10 days, you will only be allowed to enter the UK if you are a British or Irish National, or have residency rights in the UK. Even then, you need to quarantine for 10 days in a government managed hotel, at a cost of £2,285 for a single adult. A pre-departure test and two post arrival PCR tests are required too.

The red list is designed to protect against the importation of cases from countries with variants of concern or a high incidence of cases. The system was modelled on the mandatory hotel quarantine requirements of Australia and New Zealand. Both of these countries have been pursuing “COVID-zero” strategies, although Australia has now accepted that this strategy is no longer tenable with the Delta variant, at least in New South Wales.

The UK has never pursued anything close to a zero COVID strategy, so what is the red list for? I’m going to look at that question in this post.

Before we start, it is worth reminding everyone how much of an outlier the UK is in the Western World. Germany’s policy is pretty typical amongst European countries. Let’s look at what they do by comparison.

Germany’s rules

The classification of country risk which underpins Germany’s travels restrictions is managed by the Robert Koch Institute, an agency of the Federal Government responsible for disease control and prevention. The assessments are updated whenever there is a change in risk. That’s different to the UK, where classifications are changed on an artificial three-weekly cycle, with risk assessments managed and mediated by politicians. The thresholds and criteria that are used in Germany are much more transparently spelt out than is the case in the UK, and overall it seems to me a much superior system. The latest update can be found here.

The most restrictive conditions apply for “countries affected by coronavirus variants”. German citizens are free to travel to such countries, but otherwise there is a travel ban in place. On return to Germany, a 14 day self-isolation period is required, but that can be carried out at home. A pre-departure test is needed, but there is no requirement for post-arrivals testing. That is similar to the current UK requirements for unvaccinated people arriving from an amber list country, who only need to self-isolate for 10 days, but also need to take two post-arrival PCR tests. If they test positive, they need to extend their self-isolation by a further 10 days.

The other difference is the number of countries which are covered. The UK has 62 countries on its red list. Until recently, there were only two countries included on Germany’s most restrictive list - Brazil and Uruguay. That was due to concerns about the Gamma variant. But the most recent update to the risk guidelines now says that “No states/regions are currently considered to be areas of variants of concern”. So 62 versus 0.

Germany’s next most restrictive conditions are for “high-risk areas”, defined as places where case numbers are high. There are 73 countries where at least a part of the country is defined as high-risk. About half of those are on the UK’s red list, with the rest mainly rated as amber by the UK. But the rules for the high-risk countries are more relaxed than the UK’s amber list rules. In both countries, unvaccinated travellers need to self-isolate at home for 10 days, with fully vaccinated people exempt. But in the UK, you also need to take either one or two expensive post arrivals PCR tests, depending on vaccination status. The UK has 134 countries on the amber list at the moment.

Ironically, one of the countries that Germany rates as “high-risk” is the UK, due to the high level of cases currently.

What variants are we worried about anyway?

Germany has acknowledged that there aren’t any variants out there that are worse than the Delta variant that it already has. The UK recently had to concede that keeping countries like India on its red list because of the presence of the Delta variant makes no logical sense, given that it makes up virtually 100% of UK cases . However, it continues to fret about other variants. Only a few days ago, it moved Thailand to the red list citing the presence of cases of the Beta variant.

In addition to Beta, which variants is it concerned about? In the most recent Weekly Test & Trace report, the government split the variants that it is monitoring in its arrivals testing programme into three categories, which they label “Standard Priority”, “High Priority” and “Very High Priority”. Let’s look at the specific variants they include in each category, starting with the lowest risk catagory.

Standard Priority Variants

The Standard category includes the Alpha (B.1.1.7) and Delta (B.1.617.2) variants that we already have. It also includes B.1.617.3, Delta’s underachieving sibling, and B.1.1.318, which made a brief appearance in the UK in the Spring before it got killed off by the Delta wave. These are the variants that have been or still are in general circulation in the UK. The government isn’t worried about these.

At the other extreme, we have the Very High Priority variants. Presumably these are variants that would get a country sent straight to the red list. Two of them have WHO names, Lambda (C.37) and the freshly named Mu (B.1.621). We also have the so-called Nepal variant, which is Delta with a K417N mutation, and two as-yet unnamed variants, C.36.3 and AV.1.

Where have each of these variants been spotted in the world, and how they are doing against other variants?

Lambda (C.37)

In terms of cumulative numbers, 36% of the confirmed cases of Lambda have been found in Peru, with Chile in second place at 27%. The rest of the cases are mostly in Latin America and the USA, with a few cases cropping up in Spain, France and Germany.

Looking at the combined prevalence data for Peru and Chile, Lambda has been growing at a similar rate to Gamma, but recent data suggests it is in retreat now that Delta has arrived.

In the USA, it peaked at 0.4% of cases at the end of June, but has now essentially vanished.

I can understand why the government was worried about it, but it seems very likely now it is not as scary as Delta. Maybe we need a few more weeks of data, but my bet is on Delta winning this race.

Mu (B.1.621)

This variant has only just acquired its WHO name, but already seems destined to fade into the pandemic history books. This is another Latin American variant that began in Colombia and then spread into Mexico and the USA, with a few cases making it into Europe via Spain. The presence of this variant was one of the two reasons cited for moving Mexico to the red list at the start of August (the other was rising case numbers).

In Colombia, it is still the dominant variant and seems to be able to “outcompete” Gamma. However, Delta has only just arrived in the country and it is quickly making inroads.

In Mexico, Mu never got that high as a share of cases and has now been squashed by Delta. The same thing happened in the USA.

Nepal variant (Delta + K417N mutation)

The so-called Nepal variant, sometimes also referred to in the media as “Delta Plus”, was cited as one of the reasons for moving Portugal from green to amber at short notice. The reason the government is so jumpy about this variant is that they are worried about a version of the all-conquering Delta variant that might acquire a mutation which gives it a greater level of vaccine evasion.

To date, 3,156 examples of Delta sequences with this mutation have been uploaded to GISAID in total, with about 430 a week being submitted recently. Over 90% of the recent submissions are coming from the USA, with the majority in California. However, that is less than 1% of all US Delta cases and that proportion has been holding pretty steady since May. It doesn’t look like Delta variants with this mutation are showing any sign of growing faster than other Delta cases.

The country with the second biggest number of confirmed cases of this variant is actually the UK, with 0-17 cases a week being submitted to GISAID since May. Once again, that number hasn’t been growing at all, with an average of 12 cases a week being detected in August.

C.36.3

This variant initially appeared in Egypt but hasn’t been seen there since June. Admittedly, Egypt does so little sequencing (1-2 cases a week) that this doesn’t tell you very much.

The largest number of cases that have been reported come from Germany, the USA, Switzerland, the UK and Italy. But it seems to have disappeared there in recent months and those countries do enough testing to suggest that it really has died out there.

AV.1

The final “Very High Priority” variant is AV.1. Only 220 cases have ever been seen, 70% of which were in the UK and almost all the rest in the USA. In both countries, it died out three months ago. Not much of a “scariant”.

It seems to me that all of the “Very High Priority” variants have either died out already or are on their way to extinction in the face of Delta.

High Priority

What about the middle risk category? Given how non-scary the Very High Priority variants look, you won’t be surprised to see that none of these seem to be much of a worry either.

This category includes most of the other WHO named variants. Beta, Gamma, Eta, Theta, Kappa and Zeta. Let’s look at how they have fared in the countries where they have been most prevalent.

Beta originated in South Africa, but has been driven to virtual extinction by Delta.

Brazil is Gamma’s home. The sample sizes for the last few weeks are quite low, which makes the trend a bit less clear, but another clear win for Delta in my books. This chart also shows how puny Zeta is.

None of the others is any scarier. Eta appeared in Canada, the USA and a few other countries and then disappeared again. Theta was found in the Philippines and was killed off by Alpha and Beta. Kappa was a sibling of Delta which appeared in India early on in the Delta wave but died out pretty quickly.

As a final demonstration of how non-scary these variants are compared to Delta, I offer as my final exhibit what has happened in Spain. The country has good sequencing data and vaccination levels which are similar to the UK, so is a good test case of how variants which have a level of vaccine immunity perform in a highly vaccinated country. Given the country’s close connections with South America and the large amount of travel from other European countries, it has had outbreaks of all the main variants over the course of the pandemic. None of them really made much headway even against Alpha and they’ve all been blown away by Delta.

Of course, it could be the case that new variants do emerge which are more worrying than Delta. But at the moment, there doesn’t seem to be anything out there that justifies locking people up in hotels at great expense. Especially as any such theoretical new variant could emerge anywhere in the world. Many of the biggest mutations occurred in a single immunocompromised individual fighting the virus over a long period.

Countries with high case numbers

Maybe the red list is justified for countries with high case rates, because of the risk of importing large numbers of cases? There are a few red list countries with very high case rates, like Georgia (855 weekly cases per 100,000 at the last review date), Cuba (536) and Botswana (494). But Dominica had a case rate of 785 and stayed green. So did Israel with 481. So high case numbers don’t seem to be enough to get you listed as red by themselves.

Everyone travelling to the UK has to take a pre-departure test, even if they are fully vaccinated. That is true even for green list countries. But as I’ve said a number of times, a single test cannot guarantee that a person is not infected, so a certain proportion of travellers will arrive in the UK with COVID. I looked at how big that risk was in this post, and showed that even travellers from red list countries were less likely to be infected on arrival than a person selected at random in the UK.

So what is the red list for?

Once the UK catches up with Germany and acknowledges that there are no existing variants in circulation in the world that are worse than Delta, what is the point of the red list?

The only remaining logic for the red list would be for countries where we think there is a high risk of a dangerous new variant emerging. A very high case rate is one reason to be concerned. Another is where sequencing data is poor or non-existent. For such countries, the first we would hear about such a variant could be after its arrival in the UK. Until such a theoretical new variant actually does emerge, this seems to be the only role for the red list. It is a list for countries where infection rates are known to be very high, could be very high (where low rates of testing mean lower case rates may be misleading), and which also have poor sequencing data. Thailand and Montenegro were recently added to the red list with exactly that justification:

“The high rates combined with lower levels of published genomic surveillance in Thailand and Montenegro than other countries, mean that an outbreak of a new variant or existing variants of concern (VOC) or variants under investigation (VUI) cannot be easily identified before it is imported and seeded across the UK,” said the DfT.

But do we really think that by the time we found out about such a variant, it wouldn’t already have got to the UK via a third country which doesn’t have such draconian travel restrictions? Like via green-listed Germany, for example? Even Australia, with ample warning about Delta and a completely closed border has failed to keep the variant out. The best that could be hoped for is to slow down the arrival of any new variant.

In any case, 62 red-listed countries seems excessive to me. If the red list was abolished completely and only amber and green were retained, the UK’s border controls would still be more restrictive than Germany’s are today.

Maybe the red list made sense when it was established. But like many COVID policies that were put in place at the height of the crisis, it is looking increasingly like something that should now be dismantled, or at least put into “standby mode”, to be reactivated if a new scary variant is discovered before it has already arrived in the UK.

Let’s hope the politicians have the courage to look at the facts, ask themselves whether they really know better than every other country, and admit that it is time for a change of policy.

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Robert Boyle