– There seems to be a common assumption that an omicron variant will replace a delta mutation, just as delta has replaced alpha, beta and gamma before that again. This may be the case, but it is by no means certain.
writes epidemiologist and virologist Trevor Bedford at the Fred Hutchinson Cancer Research Center in Seattle Twitter. In a long chain of letters, he explains why.
According to Bedford, we are scientifically faced with three possibilities:
One possibility is that an omicron mutation could take over the delta job.
We could also have a long-term “double epidemic” where both variants destroy a community at the same time, or we could see a wave of omicron infection followed by a new delta wave that eventually causes the omicron to die.
– Can you coexist
How could that be, you might be wondering?
Bedford explains that the more an immune omicron evades delta-specific immunity, the more the two variants acquire distinct ecological niches and thus can coexist without one stepping on each other’s toes.
Immunization or immune flight is what happens when a pathogen is able to avoid the shutdown of the immune system it is facing. It can be caused by specific mutations or mechanisms that prevent it from being effectively detected or attacked by the immune system, according to Wikipedia.
Bedford shared a number of models where he calculated omicron and delta spreads. It is stated here that the greater the immune evasion, the less impact of omicron spread on delta virus spread.
Line Vold, director of the National Institute of Public Health’s Division of Infection Control and Emergency Preparedness, explains to Dagbladet how this could happen:
– This is something that has been discussed internationally. The discussion arose because Omicron is so different from Delta, that one wonders to what extent one variant provides protection against another, says Fuld – and explains:
So if you don’t have a certain cross-immunity, you can have two that are much more different. Whereas if you get good cross-delta omikron protection, you’ll see such an evolution to a lesser degree.
– It grows faster
She says it will now be exciting to follow the further development in countries that we know are experiencing rapid omicron growth, not least in Norway – where she sees omicron on the cusp of establishing itself well.
– Omicron has a fairly steep growth rate. In fact, it has the fastest growth rate of the previous variables of concern that have proliferated in Norway. It is growing faster than both Alpha and Delta when they entered the country. Then we’ll see if it leads to delta displacement, and how development will continue, she tells Dagbladet.
According to the latest FHI risk report, published on December 13, they concluded that Omicron has greater dispersal capacity than the delta variant.
– The main reason is that the omicron variant largely bypasses immunity after infection or vaccination, they explain and detail:
– Then there are many in our fully vaccinated community who are likely to get infected and pass the infection further. Fortunately, vaccinators may still have good protection against the dangerous path.
The National Institute of Public Health has already published some models of how Omicron has spread in Norway.
They stress that estimates of when omicron will dominate are uncertain, because the growth rate and number of omicron cases present in Norway are highly uncertain.
– Hints about the score
One such model shows that if the omicron continues to grow at the same speed, the omicron could make up more than half of the cases in Norway sometime between December 18 and 23.
But in these estimates, the variables are modeled independently of each other. If the two types of virus have an effect on each other, as Bedford suggests, it could mean we’d see a very different picture.
If the omicron and delta were to rotate simultaneously, Bedford believes we can expect higher levels of viral circulation than in the scenario where one mutation replaces the other.
“I very much hope we see a shift, but we should see the first hint about the outcome in the next few weeks, as we’ll see to what extent microwaves will reduce delta rotation in the US and Europe,” he writes.
“Organizer. Social media geek. General communicator. Bacon scholar. Proud pop culture trailblazer.”