A colorized electron micrograph image of a cell that has been exposed to the SARS-CoV-2 virus is isolated from a patient sample.
Science source
A crowd of more than 100 people gathered at a restaurant for a Christmas party. Most of the guests were protected from diseases. One returned from South Africa a few days later and was carrying the omicron variant of the disease.
About 70% of the partygoers were exposed to something.
The scientists concluded that omicron was highly transmissible among fully-vaccinated adults.
omicron's worldwide ascent makes it clear that the party wasn't an isolated example. The new variant has been more successful than the previous variant in every country it has been in. There have been record highs in parts of Europe and the U.S., where half a million new infections have been recorded in a single day.
"This is a game-changing virus, especially in the vaccine population, where people have had a level of invincibility," says a professor in the Department of Immunology and Microbiology.
In a world where vaccinations and infections have built up immunity, other variant were having trouble gaining a foothold. Omicron is thriving.
"This changes the equation for everyone," says Chanda.
Scientists are trying to figure out what caused omicron's lightning quick spread.
They're starting to piece together why the new variant is so infectious, and whether assumptions about how to stay safe need to be changed.
How does it fare in the air?
omicron's best trick so far is dodging our immunity, which is what helps explain its success more than anything else.
Many more people are at risk because of the variant's many mutations on the spike protein. Because of that, "immune escape" alone could be the reason why the variant looks so contagious.
The original strain of the coronaviruses spread at a very fast pace despite the world's newfound immunity.
The playing field for the virus is different now than it was in the early days, says Dr. Joshua Schiffer, an infectious disease researcher at Fred Hutchinson Cancer Research Center. The majority of the variants we've seen couldn't survive in this environment. He says that even though it was at a "tie," it was not growing very rapidly or decreasing very rapidly.
The variant's ability to evade the body's immune defenses is said to be a key factor in its dominance.
Researchers found that omicron is more infectious than the delta variant among people who have been vaccined and boosted.
There was no difference in the rates of infections between delta and omicron for people who were unvaccinated. That would mean that the omicron variant is not more transmissible than the delta variant.
The findings would support the idea that omicron's increased transmissibility can be attributed to its immune evasiveness.
This is also what a small study from the University of Maryland may suggest, although the findings are preliminary and yet to be peer reviewed.
Researchers measured how much virus people with omicron were releasing into the air after shouting and singing. The amount of virus that was exhaling into the air was comparable to the amount that was shed by unvaccinated people.
The amounts were not much higher than expected by the leader of the study.
The findings suggest that the spread of omicron could be linked to the fact that more people are getting vaccine and that more people are getting the same vaccine. If the results hold true, long distance transmission is unlikely to become a new concern with omicron, above and beyond what has already been seen with other contagious variants.
The source strength of the disease is so intense that even if you are in the next room, you are still at risk of getting it. "You don't see much of that with this virus, because it gets so watered down by the time it reaches the next room", said the person.
There is a negative side. The vaccine doesn't mean you're not going to transmit it to someone else.
He says that the findings are limited to those who are vaccine-vaccinated.
Omicron has other advantages that could give it a leg up.
It's possible that omicron has additional advantages that make it more contagious than other versions, because of the way it breaks through our immunity.
Maybe omicron can make more copies of itself? Maybe it sticks to cells more effectively. Maybe it's better to hang in the air.
"Any of those things would make the virus more spread," says Schiffer of Fred Hutchinson.
One key difference between omicron and other types of infections is how quickly someone becomes infectious.
Omicron appears to have a shorter period of time for people to get sick. The study found that the period of time between the outbreak and the next one could be three days. The CDC puts the period at about three days.
"That's a pretty significant difference," says Schiffer. There are more cycles of infections and less time for people who are exposed to take precautions not to expose others.
A study from Hong Kong in December led scientists to think that omicron may be able to replicate better in certain cells and thus have a leg up against delta.
Researchers found that omicron was 70 times faster than delta in reproducing tissue samples from the bronchus. The original version of the coronaviruses that was first identified in China had more trouble infecting cells in lung tissue than omicron did.
"If most of the replication was happening in your lungs, you could be getting more virus in your upper respiratory tract than you would be," says the University of SASKATCHEWAN's Angie Rasmussen.
Omicron spreads through respiratory droplets at close range and through virus particles that float through the air and can stay suspended for quite a while, especially in places with poor ventilation.
If you have a sore nose, you might have more virus in your respiratory secretions, which can come out as mucus, if you have a faster bronchus tissue.
Airborne concerns as omicron spreads.
Linsey Marr, a professor of engineering at Virginia Tech who studies how viruses transmit in the air, says that faster replication in the bronchus is one of the two most likely explanations. She says that if you are an infectious person, you can either release more virus particles into the air or breathe in fewer of them.
While the Hong Kong study focused on what happens in the lab, a cautionary tale of omicron spreading through the air has emerged from an isolation facility there.
In a report published in early December, Hong Kong scientists describe how a traveler in a hotel room was able to transmit the disease to another person in the hallway. The most probable explanation is airborne transmission across the corridor.
"That suggests a small amount of the virus was able to cause an illness," says Dr. Michael Klompas, an infectious disease physician and hospital epidemiologist. He says there is no data yet to prove that omicron requires a smaller dose than previous versions.
Early anecdotes need to be interpreted with care. Hotels and other places that can be used to isolated travelers are hard to turn into a Quarantine facility.
Is it possible to catch omicron more easily through the air than other versions? "I don't think that's known." It's clear that you can catch it more easily.
A reassuring point.
Scientists say it's important to realize that the coronaviruses has not evolved into a new virus despite many unanswered questions.
The rules have not changed, but the margin for error has decreased.
If you want to minimize your personal risk, wear a high quality mask like an N95, choose outdoors over indoors, and avoid large gatherings with people who are not vaccine-free.
You should try to apply as many of the risk reduction measures as possible.
People have relied on the vaccines as their only defense against omicron, which makes face-to-face interactions riskier. "If you walk into a room full of people and someone is sick, the chances have increased that you will get the virus", whether you're boosted or not.
