Americans are traveling and gathering for the holiday season just as a slew of communicable diseases have begun to spread, raising risks for people in airport security lines, packed bars, and joyfully crowded homes.
Whooping cough, walking pneumonia, RSV, COVID-19, and flu — “all of them are circulating,” says Scott Roberts, MD, an infectious disease specialist at Yale School of Medicine in Connecticut. There’s concern about sudden upticks because “everyone is traveling and mingling.”
What’s more, the United States appears to be entering a post-COVID-19 period of heightened spread for some diseases. The Centers for Disease Control and Prevention (CDC) projects that “peak hospitalizations from all respiratory viruses [will] be substantially higher than they were before the emergence of COVID-19.”
Among the reasons cited by infectious disease experts:
Protective measures taken during the pandemic — such as social isolation, masking, and vaccinations — kept down the spread of viruses besides COVID-19. For example, the CDC notes that “it’s likely mitigation measures used during the pandemic (e.g., masking, remote learning) lowered transmission of pertussis [whooping cough].”
In the absence of those measures now, more people are being exposed to those viruses again. The CDC reports that cases of whooping cough are “ beginning to return to pre-pandemic patterns.”
Hesitation and weariness about COVID-19 vaccines decreased inoculations for other diseases as well, which has left more people unprotected. For example:
- The CDC reports that from the 2019-20 to the 2022-23 school years, coverage rates among kindergartners for state-required vaccines dropped from 95% (which had been the level for a decade) to about 93%.
- Among adults, the CDC finds mixed vaccination trends in recent years, with some troubling decreases. Adult flu coverage “has steadily declined since the 2020-21 season,” the agency reports. The 44.9% vaccination rate in 2022-23 was two percentage points lower than it was the previous year.
- In an October survey by the Pew Research Center, 60% of respondents said they do not plan to get the latest vaccine to protect against COVID-19.
Infectious disease experts urge awareness but not panic. These illnesses “can put you out of commission for days,” but for some people can also threaten long-term health, says Amanda Simanek, PhD, MPH, associate professor in the Chicago Medical School at Rosalind Franklin University of Medicine and Science.
Yet at this point, infections are rising slowly, mostly in a few geographic areas and among a few demographic groups. Therefore, most people can take selective protective measures, such as masking in certain high-risk environments, taking at-home tests before gatherings where people might be particularly vulnerable, and getting vaccinated.
Here is the status of several diseases, followed by advice about protection during the holiday season and into the winter.
Infections
Whooping cough (pertussis): Whooping cough is a highly contagious bacterial infection that often begins with cold-like symptoms, but the coughing can last for weeks or months.
Nearly six times as many cases had been reported by late November this year as had been reported by the same time last year, according to the CDC. The annual number of cases ran from 15,000 to 48,000 during the decade before the pandemic, then dropped significantly during the pandemic (bottoming out at 2,116 in 2021) before climbing back to about 25,000 so far this year.
“There are early signs that waning childhood vaccine uptake is causing surges in whooping cough,” Roberts says.
Walking pneumonia (Mycoplasma pneumoniae): Symptoms caused by the Mycoplasma pneumoniae bacteria are similar to those of chest colds and pneumonia, including fever, cough, and a sore throat. Serious complications, although rare, include worsening asthma, severe pneumonia, and encephalitis, according to the CDC.
Infections have increased this year over last year, especially in young children, according to CDC data through early October. Most noteworthy is the increase in cases among children ages 2 to 4 years old, from 1.0% to 7.2%. The bacteria “historically hasn’t been recognized as a leading cause of pneumonia in this age group,” the CDC notes.
The disease has also increased this year among children ages 5 to 17, from 3.6% to 7.4%, according to the CDC.
RSV (Respiratory Syncytial Virus): This common respiratory virus usually causes mild, cold-like symptoms, but cases can be serious, especially in very young children (under 6 months) and older adults (70 and older).
Infection numbers are “elevated and continue to increase” in the southern, eastern, and central United States, and emergency department visits and hospitalization rates are increasing in young children under age 4, according to the CDC.
Weekly hospitalization rates for all ages have been rising since September. Simanek says this aligns with the typical RSV season, which runs into March.
COVID-19: Positive test results have stood around 4% in recent weeks, with weekly deaths ranging from about 160 to 600, according to the latest data from the CDC. COVID-19 cases increased in August and September, and have since declined a bit.
This compares with 2,578 weekly deaths during the last COVID-19 surge, in January 2024, and the overall peak of nearly 26,000 weekly deaths in January 2021.
Flu: Influenza is increasing “slightly” among children but remains low nationally, the CDC says. Positive clinical lab tests have been increasing for several weeks (standing at 2.5% of all tests in the week ending Nov. 23) and that trend is expected to continue.
Flu ranks among the most damaging communicable diseases in the United States. The CDC estimates that each year, from 2010 through 2023, influenza caused 41 million illnesses, 100,000 to 710,000 hospitalizations, and 4,900 to 51,000 deaths.
Protections
People can take numerous steps to protect themselves from infection or severe illness, and from transmitting a disease to others. Roberts urges everyone “to take stock” of the risk factors in various travel and gathering environments.
“I will view the question differently if I am [gathering] with my young, healthy college friends versus my family dinner table, where some people are elderly or might be on chemotherapy,” he says. “What I really worry about are vulnerable people: very old, very young, or immunocompromised.”
Masking
“Masking is a tough issue because many people don’t want to do it,” Roberts notes.
Michelle Barron, MD, senior medical director of infection prevention and control at UCHealth and professor of medicine at the University of Colorado School of Medicine, recommends masking in certain high-risk situations, mainly those that bring together lots of people from various places to an indoor space, with no knowledge of who among them has taken precautions or might be infected. These situations include airports, especially in security lines; on planes before and after the flight (because the air-circulation systems are strong during flights); on crowded trains and buses; and when sitting adjacent to someone who is coughing or sneezing (such as in a theater).
Says Simanek: “Why not capitalize on another layer of protection in those high-risk environments?”
If you think you are going to be next to someone who is highly vulnerable, such as a very old or immunocompromised person, consider bringing a mask. If you are sick, you should mask to protect people next to you.
Tests
If you have cold-like symptoms, consider taking an at-home rapid test before visiting with people indoors – especially infants, elderly relatives, and those who are immunocompromised. The federal government has approved at-home tests for flu, COVID-19, and RSV. (Several of these are available for free at pharmacies or through the mail, as listed on the websites.) Lab tests are reliable for whooping cough.
“It is important, at least for COVID-19, to remember that a single negative test isn’t that informative on its own,” Simanek cautions. “If you have symptoms, it’s a good idea to test again in one to two days, to make sure you didn’t have a false negative.”
Vaccines
COVID-19: The Food and Drug Administration approved three COVID-19 vaccines for this fall and winter — two that are made with messenger RNA (by Pfizer and by Moderna) and a traditional protein-based vaccine (by Novavax). All three target recent subvariants of the omicron variant, which has been the dominant COVID-19 strain in the United States.
Flu: The annual influenza vaccine is the same type for just about everyone. This year’s vaccine targets influenza A(H1N1), A(H3N2), and B/Victoria. The CDC recommends an enhanced vaccine for those 65 and older.
RSV: There are vaccines for pregnant women and people over 60, and antibodies for babies. The vaccines are intended to be once-in-a-lifetime inoculations, although the recommended frequency could change in response to new variants in coming years.
For more information about vaccines for the three diseases above, including who should get them and where to get them, go to vaccines.gov.
Whooping cough: This is covered in the DTaP (Diphtheria, Tetanus, and acellular Pertussis) vaccine for children through 6 years old. States require this vaccine for enrollment in school (although various exemptions exist). Whooping cough is also covered by the voluntary Tdap (Tetanus, diphtheria, and acellular pertussis) vaccine for everyone else. Because protection fades over time, the CDC recommends that adults get boosters. Learn more here.
Walking pneumonia: No vaccines are available for this, but there are vaccines for pneumonia, which is different.
When to get the vaccines: The diseases peak and ebb on slightly different cycles. Nevertheless, at this point in the season, infectious disease experts recommend immediately getting all the vaccines you still need. (They typically take several weeks to reach full effectiveness.) The main reason is efficacy, says Barron at UCHealth. She worries that people who try to spread out their vaccinations will invariably forgo some of them.
“You’re better off getting [multiple] shots than getting one shot and saying, ‘I’ll get the next one the next time,’” Barron says. “The next time doesn’t end up being convenient.”
