Omicron’s best trick by far is how well it dodges our pre-existing immunity, so that comes from either the vaccines, getting infected or both, reports npr.
Delta Vs Omicron
On that playing field, the majority of the variants that we’ve seen couldn’t survive. And the delta virus could survive, but really at a tie, where it was not really growing very rapidly or decreasing very rapidly.
Schiffer’s at the Fred Hutchinson Cancer Research Center says, ”now along comes omicron, and it’s thriving because it has these mutations that let it get by the vaccines pretty easily. So all these people that delta couldn’t get to, omicron can. But what we’re trying to figure out is whether omicron has other things going for it, aside from breaking through the vaccines, that explain why it’s spreading so fast.”
A study from Hong Kong that looked at samples of human tissue taken from the bronchus. And these are the airways connecting your windpipe to the lungs. And scientists found that omicron multiplies 70 times faster than delta in that tissue. And at the same time, they also found it does not do a great job infecting cells that are deeper in the lungs.
“You’re shedding more virus in your upper respiratory tract, meaning out your nose. So potentially, you could be shedding more than you would be if most of the replication was happening deep in your lungs”, says Angie Rasmussen.
Is omicron inherently more contagious than delta?
Scientists in Denmark looked at how well omicron spreads in households, and they compared that to delta. And first, they found omicron is substantially better at infecting vaccinated people, so that’s no surprise.
But when they only looked at unvaccinated people, the interesting thing is they found no difference between delta and omicron. The infection rates were the same. So that suggests that omicron’s big competitive advantage over delta is simply that it’s able to infect vaccinated people.
Are vaccinated people contagious?
A small study from the University of Maryland that tried to get at this, and this research was done in a lab where you can measure how much virus is being exhaled by people infected with omicron. Dr. Don Milton led the study, and he says four of the five people had detectable virus in their breath.
“These were vaccinated people, and they’re shedding frequently. But what’s striking is I was expecting to see the amounts be much higher, and they’re not”, Don Milton.
Milton says his experiment did not find that vaccinated people are spewing out tons of virus like he had suspected. But the bad news is most people who are vaccinated appear to be very capable of spreading the virus. And this could well be one reason the virus is spreading as quickly as it is, even if it isn’t making vaccinated people very sick.
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Source: npr
