Three weeks ago the world found out that there was a new variant of the SARS-CoV-2 virus which had lots of mutation. The variant, named Omicron by the World Health Organization, seemed to spread way faster than any previously known ones.
Little else was known about Omicron at that time:
There are many open question about the new variant of concern:
- How fast does this variant really spread?
- Is it more infectious?
- Does it cause a more severe illness?
- Is it more deadly?
- How well do the vaccines hold up against it?
From the current data none of those questions can yet be answered. It will take two to four weeks to find out.
Some of those questions can by now be answered. Others are still open as there seems to be contradicting evidence for either side.
- How fast does this variant really spread?
Very fast. Britain has seen a doubling of new Omicron cases every 2.5 days. In London Omicron is now the dominant variant. New York City sees a rapid rise of positive Coviod-19 tests:
New York City’s Covid-19 positivity rate doubled in just three days as the city battles a virus surge ahead of the holidays, Dr. Jay Varma, a top health advisor to Mayor Bill de Blasio, tweeted Thursday.
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From Dec. 9 to Dec. 12, the percentage of positive tests in the city spiked from 3.9% to 7.8%. “This is #SARSCoV2 evading both vaccine & virus induced immunity against infection unlike any variant before,” Varma added.
In Denmark, which has an excellent surveillance system, the Omicron variant already made up 34% of all Covid-19 cases on December 14. The number will be much higher today. The vaccination rate in Denmark is over 90%. Denmark also sees a silent community spread and has had super spreading events with large numbers of infected people.
- Is it more infectious?
It is obvious by now that the current vaccines do not protect one from becoming infected with Omicron.
On November 26 some 111 participants took part in a Christmas party in Oslo, Norway. All were vaccinated. The invent was indoor and no masks were worn. 80 participants were diagnosed as infected with SARS-CoV-2. Over 70% of those cases reported several Covid symptoms. Only one case was completely asymptomatic.
Compared to all other variants Omicron is definitely more transmissible and infectious. It is therefore even more important to keep ourselves protected by non-pharmaceutical measures, i.e. masks and good ventilation, as much as possible.
- Does it cause a more severe illness?
We still do not know for sure.
The news from South Africa, where the Omicron variant was found first, is uplifting:
South Africa delivered some positive news on the omicron coronavirus variant on Friday, reporting a much lower rate of hospital admissions and signs that the wave of infections may be peaking.
Only 1.7% of identified Covid-19 cases were admitted to hospital in the second week of infections in the fourth wave, compared with 19% in the same week of the third delta-driven wave, South African Health Minister Joe Phaahla said at a press conference.
Health officials presented evidence that the strain may be milder, and that infections may already be peaking in the country’s most populous province, Gauteng.
Still, new cases in that week of the current wave were more than 20,000 a day, compared with 4,400 in the same week of the third wave. That’s further evidence of omicron’s rapid transmissibility, which a number of other countries, such as the U.K., are also now experiencing.
Here is more detailed data from South Africa. The hospitalization rate is much lower than in earlier waves. Hospital stay time is also significant reduced.
Absolute Covid-19 death in South Africa have not increased despite a huge wave of Omicron cases.
However, death through Covid-19 is usually only three to four weeks after the onset of symptoms. The number of death in South Africa could still go up. One has also to consider that the season in South Africa is currently summer while the northern countries are now in winter times during which respiratory illnesses usually hit harder. South Africa had also had a high rate of immunity through prior infections and it has a relative young population.
Contrast South Africa with a modeling study by the Imperial College in London which found that Omicron could be just as severe as the Delta variant which had caused the previous wave. 'Could' is the operative word here. Modeling must be based on data and we have too little yet to make really good predictions.
Side note:
A university in Hong Kong has made experiments with Omicron in cells from the upper bronchia and in cells deeper within the lungs. The researchers found that Omicron infects and reproduces in upper bronchia cells much better than earlier variants while it infects less cells than other variants more deep within the lungs. (The paper on the study is not out yet and I have only heard a discussion of the preliminary report on a German public radio podcast today.)
If the findings from Hong Kong turn out to be true they could explain the higher transmissibility of Omicron as well as the lower death rate.
Covid-19 caused by non-Omicron variants starts with the replication of viruses in the upper respiratory tract. About a week after first symptoms the virus wanders down into the lower respiratory tract and into the lungs. This is when hospitalization is usually necessary as oxygen shortages will follow and the immune system will start to go berserk and attack the body itself.
A higher growth of Omicron in the upper part of the bronchia would explain the higher transmissibility of Omicron as more virus could be emitted through breathing and speaking. A lower growth in the lower parts of the respiratory system would explain the lower number of hospital admittances in South Africa.
The evolutionary explanation for the above would be a typical optimization of the virus variant for total distribution. More transmissibility helps with that while killing the host does not.
Please take this side note with a large pinch of salt as no extensive paper from Hong Kong has yet been peer reviewed of published. While it is a possible explanation for what can be seen in the data from South Africa other effects could play more significant roles.
- Is it more deadly?
So far the answer for Omicron infections seems to be no. But that does not mean that there will be less death.
The Omicron infection wave will try to drown all of us. The numbers in the U.S. easily could go up to a million new infections per day. It will be impossible to get PCR test results as the number of new cases will exceed all testing capacities.
If there is a 2% hospitalization rate like in South Africa that would mean 20,000 new hospital admittances per day in the U.S. With a high number of cases all health care systems will get swamped with serious cases even if the rate of hospitalization per case is low. Emergency services for other illnesses will be restricted and such restrictions mean triage and a higher number of all causes death than usual.
- How well do the vaccines hold up against it?
The vaccines do not protect against an infection with Omicron. From the perspective of transmissibility we are all not vaccinated. But the vaccinations still help.
The vaccines used in the 'west' were all based on the spike protein of the original Wuhan variant. The various antibodies the immune system has build against the spike proteins cover specific small regions of it. Many of these epitomes have changed with Omicron which has had 30 mutations within the RNA part of its genome that defines the spike protein. Some spike regions that could be attacked by antibodies against the original spike protein will no longer exist. New ones will have formed. That is why most monoclonal antibodies that have worked as therapy against the original spike will not help against Omicron.
However some of the various antibodies that were formed during vaccination will still be able to do their job. There are also the B-memory cells which have built those antibodies against the vaccine spike and which still exist in our bodies. B-memory cells 'ripen' over time and can then create more variants of antibodies as they did when they were first activated. There are also memory T-cells created against the vaccine spike which tend to attack on a wider range than antibodies and which do not care much about tiny mutations.
Even without a booster vaccine the first two shots have prepared the body for fighting the virus and will likely prevent a severe case of Omicron Covid-19 illness.
But any Convid-19 infection, even when 'mild', is still causing some violent symptoms and is putting the body through very high stress. Covid-19 is not a flu or a simple influenza. It is way worse. There is also long Covid which effects some 10% of all who had a Covid infection. It still causes serious symptoms up to a year after the infection and we have no therapy against it.
My advice to everyone is therefore to avoid an infection as much as possible. Mask up whenever you enter public transport or a building other than your home. Avoid being in crowds. Always seek good ventilation.
This too shall pass.
New vaccines will become available. Better therapies will be found. More people will be immunized.
The waves of Covid infections that come after this one will likely have lower peaks and look more like a typical seasonal influenza wave. Some people will still die from Covid just as people die each year from influenza. Covid is on its way to become a normal disease.
We will all have to get used to it.
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Note:
I will police the comments in this thread. Any hyping of unproven medications and other not science based speculations will be removed and might get you banned.