Omicron is transmitted through airborne transmission
You get it by breathing in the air that someone else has breathed out when they have Omicron. When someone is infected with Omicron they can transmit it by coughing, breathing, sneezing or even speaking.
The virus particles stay in the air, either in droplets (which are bigger particles that stay in the air for a short time and then fall to the ground) or aerosols (which are very small particles that stay in the air).
One study has found that tha virus remains infectious in the air for about 20 minutes. So after the 20 minute mark its ability to infect you drops by about 90%.
It’s appears Omicron spread most often via these airborne droplets, as opposed to getting it by touching a doorknob that someone with Omicron has touched and then touching your face, for example.
Another major difference is that Omicron targets people’s uppers airways, rather than their lungs.
With Delta it targeted the lungs, with serious cases getting lung infections, or pneumonia. Pneumonia is a serious illness which can lead to hospitalisation, intensive care and in some cases can be fatal. The symptoms of Delta lung infections include fevers, a persistent cough, shortness of breath or chest pains.
In contrast Omicron is generally found in the upper airways, in the back of the nose and in the throat.
The symptoms of Omicron appear to be more like a cold with on of the most common symptom being a runny nose. One UK-based reseracher has found that almost three quarters, 73% of infected people, will have a runny nose.
About 68% will have a headache. Fatigue is also prominent, as is sneezing or a sore throat.
The common symptoms of Delta (such as a cough, fever, altered smell and taste, chest pains) can happen, but are much less common.
Symptoms that present as a cold tend to be less serious medically than symptoms that present as a lung infection or lower respiratory tract infection. That is why hospitalisation rates for serious illness are lower for Omicron then we saw for Delta.
How does Omicron affect children?
Small children, especially under five, have very reactive airways, and if they get an upper respiratory tract infection can get croup (croup is when they wake in the night with a barking cough, or they have difficulty breathing).
So Omicron can cause croup. This has seen an increase in the hospitalisation of children compared to previous variants. But it is treatable with steroids. So it is important that parents are aware of the risk of croup and seek medical care if they are concerned.
Although the virus prefers upper airways, some people (especially the elderly and immuno-supressed) can still get serious respiratory illnesses. There will be some people who will get very unwell from Omicron.