Between measles and bird flu, there is no shortage of outbreaks to monitor. But experts suggest adding another to your radar: the latest strain of COVID, NB 1.8.1, which is surging in China and has been detected by the U.S. Centers for Disease Control and Prevention’s airport screening program in California, Washington, Virginia, and the New York City area.
Its appearance in the U.S. came just before Robert F. Kennedy Jr’s announcement on Tuesday that the CDC will no longer recommend COVID vaccines for healthy children and pregnant women.

The cases of NB 1.8.1 detected in the U.S. are, as of now, few and far between, a CDC spokesperson tells Fortune.
“CDC is aware of reported cases of COVID-19 NB.1.8.1 in China and is in regular contact with international partners. There have been fewer than 20 sequences of NB.1.8.1 in the U.S. baseline surveillance data to date, so it has not met the threshold for inclusion in the COVID Data Tracker dashboard,” the spokesperson notes. “We monitor all SARS-CoV-2 sequences, and if it increases in proportion, it will appear on the Data Tracker dashboard.”
Dr. William Schaffner, Vanderbilt University School of Medicine professor of medicine and preventive medicine, says the new variant is “kind of scattered about the U.S. at the moment, in small numbers.” It appears to be another variant of the Omicron family, he tells Fortune, “So it’s not a dangerous new mutant, but the latest cousin.”
So how worrisome is the new strain, and what should you watch out for? Below, all you need to know about the detection of NB 1.8.1.
Symptoms of the latest COVID strain
The new variant has no unique characteristics, says Schaffner, and causes mild symptoms—typically congestion or a runny nose, cough, fatigue, headache, body aches, and fever or chills.
It is highly contagious and will likely continue to spread, he adds, pointing out that there is typically a winter surge as well as a mid- to late-summer surge.
But, as over 95% of the U.S. population has either had COVID or the vaccine or both, we now have “extraordinary population immunity,” he points out.
“Now, this is not to say that Omicron is trivial, because there are on the order of 200 to 300 deaths that are occurring weekly, still due to COVID infection,” Shaffner says. “Of course, those are in highly vulnerable populations—older persons and people with chronic underlying medical conditions—by and large.”
Another lingering concern always the possibility of winding up with long COVID. “That hasn’t gone away, and that can actually follow milder infections as well as more severe infections,” he says, stressing that the data “are really quite reassuring” regarding vaccination, meaning that it not only helps prevent severe acute disease, but also reduces the risk of getting long COVID.
How to stay safe—and what vaccine protocol to follow
Recently, the Food and Drug Administration announced it was likely to limit access to immunizations among healthy children and adults under 65 this fall.
Schaffner, for one, wishes the latest recommendations had waited until the CDC’s next Advisory Committee on Immunization Practices (ACIP), set for June. “The current mechanism seems to have turned the recommendations process upside down—namely, it’s coming from the top down, rather than from the bottom up,” he says.
He points to and endorses the recommendations that, as of just before the CDC announcement, called for pregnant women to receive COVID shots. “And not just I, but the American Academy of Pediatrics and the American Academy of Family Physicians were recommending universal vaccination pending the meeting of the ACIP in June,” he says. “So I will make the observation that we could have waited just a month and have the normal process address this issue.”
People who are at higher risk—older people, those with chronic underlying medication conditions, and those who are immune compromised—should certainly consider vaccination.
“And then dust off your masks,” Shaffner says. “Use them when you’re indoors in large gatherings.”
Why tracking COVID strains is important
It’s important to track the strains, explains Schaffner, “because we want to be sure that the vaccines we offer are going to provide reasonable protection against severe disease caused by these various strains.” The current belief is that the vaccines on offer will protect against the new strain.
Monitoring globally, he adds, helps public health officials from being caught unprepared by a new, aggressive strain. “Because these viruses don’t need passports. They can move rapidly around the world.”
More on illness:
As measles spreads throughout the U.S., here’s how to tell if you need a booster shot
Top virologists sound the alarm on bird flu and plead with world leaders to prepare for another pandemic
Health anxiety is becoming more common. The cost is mounting
This story was originally featured on Fortune.com
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