The dizzying speed of omicron’s spread has left Americans questioning much of what they know about COVID-19, especially following holiday travel.
“This is hitting us at a very inopportune time,” said Dr. Katherine Poehling, an infectious disease specialist and vaccinologist at Atrium Health Wake Forest Baptist in North Carolina.
Though much remains unknown about omicron, experts are beginning to understand more about the variant and how it affects people who are vaccinated, unvaccinated or who have had a previous COVID-19 infection. For example, people who are exposed to omicron appear to get sick faster and may have symptoms that are different than those of other variants.
Early evidence suggests that for most people, at least for those who are up to date on their COVID-19 vaccines, omicron appears to result in mild illness that can resemble the common cold, another form of the coronavirus. Poehling, who is also a member of the Advisory Committee on Immunization Practices, which helps guide the Centers for Disease Control and Prevention’s decisions on vaccines, said there appear to be prominent symptoms from omicron:
- Fatigue or tiredness.
- Congestion and runny nose.
Unlike in previous variants, the loss of taste and smell seems to be uncommon, she said.
But Poehling and other experts say those symptoms are based on early reports of omicron cases, not scientific studies.
“Anecdotal reports represent just one person,” said Dr. Bruce Y. Lee, a professor of health policy and management at the City University of New York School of Public Health. “We have to take them with a grain of salt.”
What’s more, they may only reflect certain segments of the population: young and otherwise healthy, as well as those who are fully vaccinated.
“It is clear that if you’re vaccinated, particularly if you’ve had a booster, omicron tends to produce milder infections,” said Dr. William Schaffner, an infectious disease expert at the Vanderbilt University Medical Center in Nashville, Tennessee.
“What we haven’t seen yet is a substantial body of information about what omicron will do in unvaccinated people,” he added.
Indeed, at least one person who was not vaccinated is reported to have died of omicron. Officials in Houston announced Monday that the unvaccinated man in his 50s succumbed to the virus.
For people who have been vaccinated, but have not had a booster, typical symptoms include more coughing, more fever and more fatigue than those who have received an extra dose, said Dr. Craig Spencer, director of global health in emergency medicine at New York-Presbyterian/Columbia University Medical Center.
There is also emerging evidence that omicron tends not to burrow deep into the lungs as much as previous variants. A study, which was posted online by the University of Hong Kong and not yet peer-reviewed, found that while omicron is less severe in the lungs, it can replicate faster higher up in the respiratory tract.
In this way, omicron may act more like bronchitis than pneumonia, said Dr. Hugh Cassiere, director of critical care services for Sandra Atlas Bass Heart Hospital at the North Shore University Hospital, on Long Island, New York.
“Usually patients with acute bronchitis tend not to be short of breath. They tend to cough and produce sputum,” he said. “Patients with pneumonia tend to be short of breath and feel more fatigued than bronchitis in general.”
A small study from the CDC found that people who had COVID-19. and are later reinfected with omicron may experience fewer symptoms than they did during their initial bout with the virus.
Still, it’s virtually impossible for people to rely on symptoms to self-diagnose an illness. In addition to omicron, the delta variant continues to circulate, along with increasing cases of the flu.
For these reasons, doctors urge people who have any cold symptoms or flulike symptoms to get tested.
According to early data, the time it takes for an infected person to develop symptoms after an exposure may be shorter for omicron than for previous variants — from a full week down to as little as three days or fewer.
While much more research is needed, it makes scientific sense that a highly contagious virus like the omicron variant would have a shorter incubation period. Its goal, after all, is to infect as many people as possible, as quickly as possible.
“That’s why the spread is occurring at a much faster pace,” said Dr. Anita Gupta, an anesthesiologist and critical care physician at the Johns Hopkins School of Medicine. She added that it’s possible the incubation period could be shorter or longer depending on a number of variables, including age, underlying health problems and vaccination status. “There is no hard and fast rule here.”
Given the potential for a shorter incubation period, Vanderbilt’s Schaffner advised that anyone who has been in contact with an infected individual get tested about 72 hours following the exposure.
“If you’ve been exposed and now you’re asking yourself, ‘When should I get tested?’ I think you would best wait at least three days to see if you’ve turned positive,” he said.
For the millions of people without any known COVID-19 exposure, but who are getting together with friends and family over the Christmas holiday, Schaffner said, it would be prudent to get a rapid test the day of the gathering.
Dr. Anthony Fauci, chief medical adviser to President Joe Biden, agreed.
“By all means, go the extra step, go the extra mile to get tested” to alleviate any concerns about gatherings, he said on NBC’s “TODAY” show Tuesday.
“But if you don’t have the availability of the test and you are fully vaccinated and boosted, you should feel comfortable having a holiday meal or gathering with family members who are also vaccinated and boosted,” Fauci said.
Though much remains unknown about omicron, experts say the variant could lead to long COVID-19, even with a mild case.
Patients with long-term symptoms can experience crushing fatigue, irregular heart rhythms and other issues months after their initial COVID-19 infection. This occurred during the first wave of the pandemic, and has continued to lead to long COVID-19 issues through the delta wave.
“We should assume that this variant can do the same thing that previous variants have until proven otherwise,” Lee, of CUNY, said.
Previous research, however, suggests that vaccination can greatly reduce the risk for long COVID-19.
Cases of omicron are doubling about every two days. In the past week, the percentage of omicron cases in the United States rose from 13% to 73%.
“The major question for everyone right now isn’t whether omicron is going to hit their area. It will,” said Dr. Michael Saag, an infectious disease expert and associate dean for global health at the University of Alabama at Birmingham.
“The question,” he said, “is how much disease will it cause?”
Experts continue to urge people to get vaccinated and get a booster shot to reduce the risk for severe illness.
As of Tuesday, about 61% of the population had been fully vaccinated. Just under 30% had the booster shot.
“This is going to hit us hard,” Poehling, of Wake Forest Baptist, said. But she added that the sheer speed of omicron’s spread could mean that the variant will run its course quickly. “If you look at South Africa, they seem to be doing much better now. I don’t anticipate this as long lasting.”