The US is starting 2024 in its second-largest COVID surge ever, experts say

The United States is in the middle of a wintertime COVID wave, driven by holiday gatherings, people spending more time inside, waning immunity from low uptake of the new COVID vaccine and a new highly infectious COVID variant, JN.1.

The U.S. Centers of Disease Control and Prevention released an update on Jan. 5 about the prevalence of JN.1, explaining that the new variant may be "intensifying the spread of COVID-19 this winter." Test positivity and wastewater data show that viral activity in the U.S. is higher than this time last year, with wastewater data especially rising rapidly the past several weeks. (COVID-19 deaths and hospitalizations are still lower than last year, the CDC noted.)

Cases are high globally, too, an official with the World Health Organization said during a Jan. 12 media briefing. Maria Van Kerkhove, Ph.D., WHO's COVID-19 technical lead, estimated that viral levels are two to 19 times higher than what's being reported around the world.

According to some experts and data models, the current surge in the U.S. is its second-largest since the pandemic began — after only the omicron surge from late 2021 to early 2022, which infected more people than even the early days of the pandemic.

According to Lucky Tran, Ph.D., science communicator at Columbia University Irving Medical Center, projections show as many as 1 in 3 people in the U.S. could be infected with COVID during the peak months of the current wave and up to 2 million people could be infected in a single day — data he attributed to Michael Hoerger, Ph.D., assistant professor at Tulane University School of Medicine who leads the Pandemic Mitigation Collaborative's data tracker.

Tran tells TODAY.com that "many people underestimate just how much virus is around." But research shows that once people are aware of the real levels, "they (are) more willing to wear a mask, social distance when required, to stay home and get vaccinated and take all of those measures," he adds.

Is the U.S. in a COVID wave in 2024?

Yes, the U.S. is in the middle of a COVID wave, multiple experts tell TODAY.com.

A CDC chart of national and regional COVID trends in wastewater shows the national viral activity rate of 12.44 from the week ending Dec. 30, 2023 is higher than anything seen since January 2022, as far back as the publicly available CDC data goes. (The national rate for the week ending Jan. 15, 2022, was 22.78.) However, the rate dipped for the week ending Jan. 6, 2023, to 11.79.

CDC spokesperson Tom Skinner tells TODAY.com via email that "COVID 19 in wastewater is currently (at) very high levels across the country."

"Last year, the peak of infections occurred in late December, early January. We are seeing early evidence of the same timing this year, but we will continue to monitor closely," Skinner continues.

"These levels are much lower than the Omicron wave in early 2022," he says, adding that JN.1 is the most frequently detected variant in wastewater. Skinner did not specify if the current COVID wave is the country's second-largest.

The CDC noted in its Jan. 5 statement that wastewater and test positivity data are both higher than the year before by about 27% and 17% respectively. It added that wastewater levels "are currently high and increasing in all regions."

Hoerger tells TODAY.com that based on the wastewater data collected from Biobot Analytics (which used to provide the CDC its wastewater data), the U.S. is in its second-largest COVID surge. He says his own predictive model indicates cases will continue to rise until mid-February. He estimates that mid-December 2023 to mid-February 2024 will be the peak of the current wave and that 1 in 3 Americans will be infected with COVID during this timeframe.

He says his data also show that on the highest day of the current wave, there will be 2 million new COVID cases, which would lend to many more infections than last winter, which had its highest day of about 1.7 million new infections. While CDC data suggest viral activity levels have been similar the last two Decembers, Hoerger explains that the acceleration in COVID activity in 2023 was faster than in 2022, suggesting there will be a higher peak this season.

"I think people can get a little bit too concerned about the height of the peak," Hoerger says. "What's really troubling is just the total number of days with a really high transmission based on my model or if you're just looking at the wastewater."

Dr. Albert Ko, infectious disease physician and professor of public health, epidemiology and medicine at Yale School of Public Health, agrees that focusing on peaks isn't as helpful as stressing that COVID is spreading widely in much of the country right now.

"More important than saying this is more than the last wave or two waves or three waves ago ... is that we are getting into surge, and the public should be aware about how to protect themselves," Ko tells TODAY.com.

A surge this time of year is expected, Dr. William Schaffner, infectious disease specialist at Vanderbilt University Medical Center, tells TODAY.com, and it's “perfectly reasonable” to call the current COVID wave the country’s second-largest, he says.

“But I don’t want to panic people,” he explains. “This winter increase is not going to be akin to the previous winter increases, which really stressed hospitals," though it is likely to keep medical professionals "very busy," he adds.

Tran stresses that it's important to understand the burden of COVID beyond hospitalizations and deaths being lower than they were earlier in the pandemic.

"While we're not seeing the same levels of hospitalizations or deaths as 2020 or 2021, it's still a very high baseline compared with before the pandemic, and that's something that we should still care about," Tran says. He adds that more virus circulating can also lead to increases in long COVID and chronic illness, more people (especially health care workers) missing work and other important events, and immunocompromised people not being able to access essential services, like health care.

COVID-19 mask mandates

Amid a rise in COVID cases, as well as influenza and respiratory syncytial virus (RSV), masks mandates have returned in medical settings in several states, Reuters reported:

• New York

• Illinois

• Massachusetts

• California

But even if you're not required to mask, the experts say that now is a good time to wear your N95 or KN95.

"Get your mask out again if you're going indoors, even to the supermarket," Schaffner says. "Certainly if you're traveling, going to religious services, going to that basketball game, where everybody's close together and cheering, those are environments where the virus can spread."

If you have some respiratory illness symptoms but not enough to stay home, wear a mask when around other, the experts say. And keep in mind that the CDC recommends wearing a mask for 10 days if you test positive for COVID. You are most contagious the day before your symptoms start and for three to five days afterward.

How bad is the new COVID variant?

The new COVID variant JN.1 is responsible for more than 61% of cases in the U.S. as of the week ending Jan. 6, 2024, according to CDC data. The variant may be more transmissible or better at evading immune protection than previous COVID variants, TODAY.com previously reported.

It also appears to be "intensifying" the spread of COVID this winter, the CDC said in a statement.

“The current strain right now seems to be packing a meaner punch than the prior strains,” Dr. Joseph Khabbaza, a pulmonary and critical care specialist at the Cleveland Clinic, previously told TODAY.com. “Some features of the current circulating strain probably (make it) a little bit more virulent and pathogenic, making people sicker than prior (variants).”

JN.1 COVID variant symptoms

The symptoms you'll experience if infected by the latest COVID variant, JN.1, will depend on your underlying health and immunity. But generally speaking JN.1 symptoms are similar to those caused by other variants, such as HV.1 and BA.2.86, aka “Pirola.”

According to the CDC, these are:

• Sore throat

• Congestion

• Runny nose

• Cough

• Fatigue

• Headache

• Muscle aches

• Fever or chills

• Loss of sense of taste or smell

• Nausea or vomiting

• Diarrhea

How to protect yourself in a COVID wave

The experts all agree that the current rate of new COVID cases means it's time to take precautions to prevent further spread. This is especially important for individuals who are at high risk for severe illness, such as the elderly and immunocompromised.

But even if you or loved ones don't fall into this category, by taking precautions, you can prevent spreading the virus to someone who may get much sicker than you and reduce your risk of long COVID.

So, the experts urge:

• Wearing a mask in indoor settings with lots of people

• Considering avoiding crowded settings, especially if you're high risk

• Staying home if you're sick

• COVID testing

• Getting the new COVID vaccine, approved for everyone ages 6 months and older since September 2023

• Seek out antivirals if you test positive for COVID, especially if you're high risk

It's tempting to think the pandemic is over, but Hoerger stresses that data show it isn't. In fact, Van Kerkhove recently posted on X that we're heading into the fifth year of the pandemic.

"The bottom line," Ko says, "is everybody should consider themselves under risk of getting COVID.”

This article was originally published on TODAY.com