美国国家公共电台 NPR-科学家探索奥密克戎毒株与其他新冠病毒的区别（在线收听）

Scientists explore how omicron symptoms differ from other COVID signs

Transcript

Most people know the telltale signs of COVID-19. But given omicron's many mutations, are the common symptoms still the same? Doctors are noticing at least some differences with the new variant.

RACHEL MARTIN, HOST:

The omicron variant is a lot different from its predecessors. It has lots of mutations. It gets by the vaccines more easily. But when it comes to actually getting sick, are the symptoms different? NPR's Will Stone reports.

WILL STONE, BYLINE: Infectious disease doctors like John Vanchiere are getting a sense of what omicron cases, at least the less serious ones, tend to look like.

JOHN VANCHIERE: Runny nose, sore throat and the cough is milder, if any cough at all - fever, it seems to be a little less common.

STONE: Vanchiere is at LSU Health Shreveport in Louisiana. He says one significant difference - loss of smell used to be a telltale sign of COVID. But with omicron...

VANCHIERE: The clinical looks more like the flu than the old COVID, right? You don't have the loss of taste and smell.

STONE: The clinical picture of omicron is still messy. But scientists in the U.K. have found the classic symptoms of fever, cough and loss of smell are much less prevalent there. And early data from Europe, Africa and now the U.S. does suggest a reduced risk of severe disease with omicron compared to delta. But some people are still getting very sick. Dr. Brendan Carr is chair of emergency medicine at Mount Sinai in New York City. He says what's clear is that fewer patients are showing up with low oxygen levels.

BRENDAN CARR: That was a hallmark of the first disease and of delta, and that is not nearly as prominent in omicron.

STONE: Good news because that means fewer people need oxygen and ICU care. This also fits with some early lab research that shows omicron does not infect the lungs as well as other variants.

CARR: That, however, isn't the end of the story. The next piece is people who have chronic medical problems - heart failure, diabetes, have hypertension, emphysema - or, frankly, are older and just a little bit less able to bounce back rapidly from getting sick.

STONE: Carr says these patients are still ending up in the hospital. Now, there are some symptoms that seem to be showing up more with omicron. For example, South Africa doctors have noticed lower back pain. But Carr says it could be that doctors are simply paying closer attention because fewer people are struggling to breathe.

CARR: When there's a car crash and the car's on fire, you're focused on the fire and less focused on the fact that the car has structural damage.

STONE: Dr. Scott Roberts at the Yale School of Medicine agrees. He says yes, omicron looks more like a typical upper respiratory infection. But...

SCOTT ROBERTS: The symptom differences between people infected with the omicron variant versus the delta variant are really more similar than they are different.

STONE: That means you may get dizzy, have a terrible fever, suffer from aches and pains, GI problems - all of which were true with delta. And Roberts says what's also still true is the risk of not being vaccinated.

ROBERTS: We are seeing about 80% of our inpatients who get admitted with COVID are unvaccinated. The 20% who are vaccinated, the vast majority of those are not boosted.

STONE: Sorting out why omicron looks different is tricky right now. Dr. Daniel Griffin at Columbia University says in part, that's because many of these clinical observations are based on patients who already have some level of immunity.

DANIEL GRIFFIN: It just seems that people who are been vaccinated ahead of time are getting much milder symptoms across the board.

STONE: This was the case even before omicron. Breakthrough cases were not as severe. People tended to have fewer symptoms and recovered more quickly. Griffin says the bottom line is your overall risk still very much depends on who you are.

GRIFFIN: It's hard for me to buy the idea that this is so much milder when I'm taking care of reinfected patients who I took care of in hospital in, you know, April of 2020.

STONE: And with so many more people getting infected, he says omicron can still do a lot of damage.

Will Stone, NPR News.

(SOUNDBITE OF FEVERKIN'S "SILHOUETTE")