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With a population 1/60th that of the United States, Denmark has already detected (n=134) more than twice as many COVID variant cases as has America (n=63), which is both a testament to their level of surveillance, and an indication of how quickly the virus is spreading there.
Three days ago, in Denmark: Statens Serum Institute (SSI) Estimate Of COVID Variant B.1.1.7 Growth, we looked at estimates that by the middle of February, the B.1.1.7 variant would become dominant in Denmark.The numbers from both countries are a massive undercounts, as only a small fraction of cases are sequenced. Denmark, however, sequences a vastly larger percent of their cases than does the U.S.
Today the SSI has published a new update that doubles down on that prediction, updates the current numbers, and calls for even tighter restrictions going forward.
(translated)
Status of development with cluster B.1.1.7
The latest results from random samples of positive SARS-cov-2 samples indicate that the proportion of infected with cluster B.1.1.7 is still growing in Denmark. Therefore, the monitoring of mutated variants is being stepped up.
Last edited January 9, 2021
The proportion of people in this country who are infected with the covid-19 variant cluster B.1.1.7 is still growing.
In Denmark, B.1.1.7 has so far been detected in 134 Danes. They were found by sequencing positive Danish samples in the period from 14 November to 2 January.
During that period, a total of 14,753 samples were sequenced, meaning that B.1.1.7 has been found in 0.9% of the samples. It appears that a new note from the Statens Serum Institut (SSI) .
Dominant from mid-February
The B.1.1.7 variant was first discovered in England, but has since been found in several other countries, including Denmark.
SSI still expects that the variant B.1.1.7 will become dominant in Denmark from mid-February. This increases the demand for Danish efforts to maintain control of the epidemic. This has increased the risk level to 5, and has led to the need for stricter restrictions.
A serious development
"It is a serious development. A total of 13% of all detected cases have been sequenced from week 46 to 53, which means that the actual number infected with B.1.1.7 is probably about eight times higher. We have also seen a clear increase in the proportion with this variant among the sequenced samples. Between weeks 49 and 52, the proportion approximately doubled from week to week ", says department doctor at SSI Rebecca Legarth. She continues "The numbers may change a little as we continuously get answers to more tests for the last few weeks".
So-called sequencing is used to detect B.1.1.7. That is, uncovering the entire virus' genetic material, which can reveal mutations and thus determine whether there are special variants such as B.1.1.7
Stricter restrictions needed
The consequences of infection spread with a more contagious SARS-CoV-2 virus variant are that the epidemic curve will be steeper and have a higher peak compared to other less infectious variants. In addition, a higher proportion of the population must be immune to obtain herd immunity.
“If we are to avoid exponential growth in infection with covid-19 in February, the infection rates and contact numbers must decrease significantly during January. At the same time, there is a need for stricter monitoring of B.1.1.7 and other mutated virus variants ", says Rebecca Legarth
The monitoring is further tightened
Seen in an international context, Denmark has a very high capacity for sequencing.
“But despite that, we do not currently have the complete picture of how many infected people are found in Denmark with B.1.1.7, or where in the country they are all. We are now working to change that, ”says Rebecca Legarth
SSI is therefore working to strengthen the monitoring of the new virus variant. This is to be done by increasing the sequencing capacity from 3,000 to 5,000 weekly analyzes in the first instance. In the slightly longer term, the intention is to increase capacity further so that all samples can be sequenced.
“In addition, there is a delay in data from the sequencing of 1-2 weeks, from a person being tested positive until a response is ready. The response time has therefore been optimized in recent weeks, but work is underway to bring it down further, ”says Rebecca Legarth.
Finally, as early as next week, a screening will be started among positive samples for, among other things, B.1.1.7 using the new "Delta-PCR" test. It is a PCR test that specifically detects one of the mutations in the new virus. This means that all positive samples can be screened for whether they have this mutation, and in this way the development can be followed closer in real time.
More contagious, but not more dangerous to the individual.
B.1.1.7 has 9 genetic changes in the Spike protein. These are 2 so-called deletions and 7 mutations. Modeling studies from England suggest that B.1.1.7 is 50-74% more contagious than other virus strains. Preliminary data from Denmark also indicate that the growth rate for this variant is 70% higher than for other variants.
However, studies do not suggest that B.1.1.7 is more or less pathogenic than other virus strains.
It is also estimated that vaccines will work against this variant, but studies are underway to determine whether the sensitivity / resistance to antibodies is the same for the B.1.1.7 variant as for the already known variants.
