Holiday cheer is in the air, and so are seasonal viruses. Influenza will pose a very high risk, with respiratory syncytial virus (RSV) not far behind, said Shaun Yang, PhD, director of the Molecular Microbiology and Pathogen Genomics Laboratory and associate clinical professor at the David Geffen School of Medicine at UCLA.
To minimize your chances of getting sick, it’s important to know your individual risk profile, get vaccinated based on current guidelines and take other common-sense steps.
Flu tops list of concerns
This year, “the biggest concern is flu,” Dr. Yang said. That’s based on a confluence of factors: a low level of immunity due to mild recent flu seasons, an uptick in travel and low vaccination rates to date this season.
Current population immunity has waned due to mild flu seasons the last few years, he noted, driven largely by social distancing, masking and reduced travel. However, with travel now rebounding post-pandemic, many people will be in crowded indoor spaces such as airplanes, trains or hotels this holiday season, increasing their potential exposure.
“I expect flu to peak in mid- to late-December, which happens to overlap with the heavy travel season due to the holidays,” Dr. Yang said.
The result, when low vaccination rates are factored in, is a “perfect storm” for infection, he noted, but one that can be downgraded if more people get vaccinated.
During the last three years, most people didn’t get vaccinated against the flu and also didn’t get the flu itself, meaning they didn’t develop any immunity, Dr. Yang explained. Any residual immunity people may have had from earlier flu infections has already waned and is also less effective against this year’s flu strain. The immunity against the flu fades away pretty quickly.
“That’s just the nature of the immunity against flu,” he said, “as well as the rapid changes in the flu virus.”
Because the flu viral genome mutates from one year to the next, in any given year, “the flu can come out and be a very different virus,” Dr. Yang explained. As the virus changes each year, with certain strains becoming more dominant, flu vaccines are updated accordingly.
As a result, annual flu shots are recommended for everyone age 6 months and older. So far this flu season, however, only about 35% of U.S. adults have received a flu shot, down about 3% from the same timeframe last year, according to the Centers for Disease Control and Prevention. Just 33% of children up to age 17 have gotten the shot, also down roughly 3%.
With this year’s flu season estimated to last until early February, “the biggest message I want to put out is get the flu shot now,” said Dr. Yang. “Don’t wait.”
The flu vaccine doesn’t just help prevent infection; it also helps reduce the severity of symptoms and lowers related risks.
Some people can have the flu and only experience mild symptoms, but that’s not always the case. People can feel fine in the first few days and then deteriorate very rapidly if they get a secondary infection, Dr. Yang explained. This includes serious secondary bacterial infections, such as Group A Streptococcus or Streptococcus pneumoniae, which can require hospitalization and be life-threatening.
While the flu is usually thought of as being most dangerous for people older than 65, those with existing health complications and very young children can also develop more severe symptoms. Even people who are young and healthy can be at risk for these secondary complications, Dr Yang pointed out. To best prevent a very severe scenario like this, he said, “all it takes is one shot.”
RSV risk remains high
Last year was a particularly bad year for RSV, a respiratory infection that’s most dangerous for very young children and older adults. Typically, RSV symptoms are similar to those caused by regular colds. However, RSV can also cause lung infections or pneumonia and can worsen existing lung or heart conditions.
Although RSV typically peaks during the winter months, RSV got an earlier start this year and has just about crested. This means it won’t be circulating quite as widely during the bulk of holiday travel, Dr. Yang noted.
However, he still recommends following the CDC guidelines for getting the RSV vaccine, which is recommended for adults older than 60 and for infants whose mothers weren’t vaccinated against RSV during the pregnancy.
Don’t overlook COVID
The one bright spot in the winter illness outlook is that COVID-19 won’t be as high of a risk compared to the last three winters, Dr. Yang noted. That’s based in part on the timing of the most recent surge in the fall and the subsequent window of immunity for those who were recently infected.
“Most people who were infected should have immunity for about six months,” which would last until the spring, Dr. Yang explained.
The flu and COVID-19 differ when it comes to longer-lasting immunity, he pointed out. People who have either gotten at least two COVID-19 shots or been infected generally develop cellular immunity, which likely lessens the severity of any subsequent COVID-19 infections.
“With COVID, my prediction is that eventually it will become more seasonal,” Dr. Yang said, making it more similar to a common cold virus.
For now, though, the CDC recommends that everyone 6 months and older receive the updated 2023 vaccine.
Keep in mind when getting vaccinated that it can take about two weeks for the full effect of the immunity to kick in, Dr. Yang noted.
Another consideration: Getting enough sleep the nights before getting vaccinated can help the immune system produce more antibodies.
What about colds?
Common colds, typically caused by the rhinovirus, can occur throughout the year and generally cause milder symptoms.
Colds typically cause upper respiratory symptoms such as a runny nose, congestion or a cough, while the flu tends to cause lower respiratory symptoms, such as breathing difficulties or shortness of breath, along with persistent fever.
Those with breathing difficulties should seek immediate medical attention, Dr. Yang said.
Other steps for healthy holidays
The likelihood of contacting all of these illnesses increases during the winter as people spend more time indoors and in closer proximity to each other. Because travelling can heighten the risk, Dr. Yang recommends that people who are considered high-risk limit their travel plans over the holidays.
Wearing a mask can be another good option, especially for those considered at higher risk. While the decision is an individual one, Dr. Yang acknowledged, people who are sneezing or coughing can help protect others by wearing a mask to keep their infectious droplets from spreading.
“Flu is typically not airborne; it’s spread via droplets,” he explained, “If somebody puts on a mask when they’re coughing or sneezing, they’ve already effectively blocked the transmission to the others.”
The second-most important step, after getting vaccinated, according to Dr. Yang: “Don’t touch your face.” That’s because touching an infected area and then touching the eyes, nose or mouth provides a direct pathway for transmitting pathogens.
Washing one’s hands is also important, he said, as is avoiding sharing food or drink with others.
Finally, pay attention to the basics – sleep, diet and exercise – to avoid getting run down, Dr. Yang noted, as this increases susceptibility to illness.
While getting enough sleep (seven to nine hours nightly) plays a role in strengthening immunity, sleep is also important when recovering from an illness.
Physical movement can also help with immunity, Dr. Yang noted, as can a diet rich in fruits and vegetables, given the variety of nutrients they contain, including beta carotene and vitamin C. Staying well-hydrated is also important, he noted.
This type of self-care can be harder during the holidays, especially when traveling, he acknowledged, but can also help lessen symptoms for those who do end up getting sick.
Still, for those who are up to date on their vaccines and aren’t in the high-risk category, holiday travel or gatherings needn’t be off the table. Those with vulnerable family members or friends should still consider wearing a mask at gatherings, however, especially if they’re symptomatic.
“You don’t want to create an environment that could increase their exposure,” Dr. Yang said, given that what’s mild for someone who’s generally low-risk can be quite serious or even life-threatening for someone who’s elderly or immunocompromised.
“What I would emphasize the most is to get your vaccines,” he said. “Then go out and enjoy your daily life.” And while it can be difficult to avoid catching a cold, the symptoms will generally be mild and quick to resolve.
“It won’t knock you out and make you so sick that you won’t be able to enjoy the rest of the holidays,” he pointed out. “I think that’s the main difference. Getting vaccinated and following these precautions will lower the risk of having a bad holiday season or a bad winter.”
Lisa L. Lewis is the author of this article.